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Friday, September 27
 

9:45am HST

GG 3 - Transcriptomic responses underlying host-pathogen interactions between resistant and susceptible Prunus accessions and two Armillaria Root Rot fungi
Friday September 27, 2024 9:45am - 10:00am HST
Armillaria root rot (ARR) caused by Desarmillaria caespitosa and Armillaria mellea represents the main cause of premature stone fruit and nut tree decline in the United States. A. mellea is a primary concern for almond and peach growers in California, while D. caespitosa threatens peach production in the southeast region of the U.S. These fungi survive as facultative necrotrophs and colonize roots of several agriculturally important crops, including peach, almond, and sweet cherry. This colonization ultimately kills the woody roots and therefore host, severely limiting the tree’s lifespan and ability to provide a return on investment for the grower. Few management options are available to slow down ARR disease progression, and no management practice eliminates ARR fungi presence in an infested field. Additionally, most of the commercially available rootstocks are susceptible to infection, with only two peach/plum hybrid commercial rootstocks (Prunus umbellata × P. persica ‘MP-29’ and P. cerasifera × P. persica ‘Krymsk® 86’) showing partial resistance to ARR. The shared plum genetic background in these hybrids, paired with the lack of ARR resistance observed in peach germplasm suggests the source of resistance originated from plum. In this work, induced genetic responses in one susceptible accession, P. persica ‘Guardian®’, and two resistant accessions, P. cerasifera ’14-4’ and ‘MP-29’, when infected with D. tabescens and A. mellea were analyzed. Additionally, expression of genes encoding effectors and cell wall degrading enzymes (CWDEs) were investigated in the ARR fungi while infecting the three hosts. The results of the infection assays revealed unique responses between each of the three hosts in their progression of disease symptoms over time and in their transcriptomes while under infection by the two ARR fungi. Analysis identified key hub genes expressed by the two resistant Prunus accessions involved in the sensing and enzymatic degradation of chitin and the upregulation of GSTs, oxidoreductases, and transcription factors. Investigation of the ARR fungi transcriptomes similarly identified host-dependent expression of fungal effectors and CWDEs responsible for degrading the cell wall components cellulose, hemicellulose and pectin. Comprehensive analyses considering transcriptomes produced by both the host and pathogen during the infection course provides a deeper understanding of the factors driving resistant and susceptible responses to ARR infection, and their effects on the infecting pathogen’s gene expression.
Speakers
SP

Stephen Parris

Clemson University
Co-authors
CS

Christopher Saski

Clemson University
NA
GS

Guido Schnabel

Clemson University
NA
JW

Jared Weaver

Clemson University
NA
JA

Jeffrey Adelberg

Clemson University
NA
KG

Ksenija Gasic

Clemson University
LC

Lichun Cai

Clemson University
NA
Friday September 27, 2024 9:45am - 10:00am HST
Coral 1

10:00am HST

CE 7 - Foliar Nutrient Concentrations of Strawberry Mother and Daughter Plants Grown in Controlled Environments
Friday September 27, 2024 10:00am - 10:15am HST
Few published studies provide foliar tissue nutrient concentrations for strawberry (Fragaria × ananassa) mother and daughter plants. Recommendations primarily focus on tissue concentrations for field-grown plants during fruit production. As controlled environment production of strawberry increases, a need exists to define tissue nutrient concentration ranges for healthy foliar tissue, for both vegetative and fruit production. Defining deficient, sufficient, and toxicity ranges will assist growers in selecting nutrient solution recipes and correcting nutritional issues that arise. The objective of this study was to identify nutrient concentration ranges for healthy strawberry mother and daughter plants grown in controlled environments. Foliar tissue samples were collected from two separate experiments: 1) ‘Albion’, ‘Fronteras’, and ‘Monterey’ grown in a peat-based substrate, and 2) ‘Monterey’ grown indoors in deep water culture. Plants received a modified strawberry nutrient solution (Yamazaki) that provided 100 mg·L-1 nitrogen (N). The percent total N provided as ammonium (NH4 ) ranged from 0% to 40% in both experiments. Plants did not exhibit any visual symptoms of foliar nutrient deficiencies or toxicities. Foliar tissue from mother (n=72) and daughter plants (n=144) were collected and analyzed individually. Nutrient concentration ranges comprised the middle 75% of plant samples (12.5% – 87.5% quantiles). Mother plant macronutrient concentrations ranged from 2.12%–2.64% nitrogen (N), 0.53%–1.23% phosphorus (P), 2.05%–3.88% potassium (K), 2.01%–3.36% calcium (Ca), 0.33%–0.56% magnesium (Mg), and 0.14%–0.28% sulfur (S). Daughter plant foliar macronutrient concentrations ranged from 2.18%–3.38% N, 0.49%–0.92% P, 2.20%–4.19% K, 1.01%–3.03% Ca, 0.31%–0.53% Mg, and 0.15%–0.30% S. Mother plant foliar micronutrient concentrations ranged from 158–233 mg·kg-1 boron (B), 1.5–5.6 mg·kg-1 copper (Cu), 57–587 mg·kg-1 iron (Fe), 131–384 mg·kg-1 manganese (Mn), and 11–29 mg·kg-1 zinc (Zn). Daughter plant foliar micronutrient concentrations ranged from 69–212 mg·kg-1 B, 1.2–4.5 mg·kg-1 Cu, 56–347 mg·kg-1 Fe, 78–315 mg·kg-1 Mn, and 18–36 mg·kg-1 Zn. In general, these macro- and micronutrient ranges overlap between mother and daughter plants. These values represent a first step in developing and refining foliar nutrient ranges for strawberry mother and daughter plants in controlled environments.
Speakers
JB

Jennifer Boldt

Research Horticulturist, United States Department of Agriculture
Co-authors
EY

Erin Yafuso

United States Department of Agriculture
Friday September 27, 2024 10:00am - 10:15am HST
Nautilus

10:00am HST

CHMG 2 - Evaluating Knowledge Gained from Extension Education Provided in a Citizen-Science Gardening Project
Friday September 27, 2024 10:00am - 10:15am HST
A citizen-science gardening project was conducted in 2023 with 300 participants from Indiana, Iowa, and Tennessee, who were recruited to compare three cultivars of compact tomato (Solanum lycopersicum) plants in an 18-week experiment. The study used a pre- and post-test format where participants were asked 15 questions that assessed their confidence levels about pest management, healthy cooking, and safe handling and preservation of home-grown tomatoes. Monthly educational sessions were delivered virtually by Extension faculty at Land-grant institutions from each state, covering the aforementioned topics. The pest-management session was the most popular with 81 live participants and 207 views of the video recording. This was followed by the healthy-cooking session with 67 live participants and 129 views. Participation and views of the last session that focused on safe handling and preservation were lower (58 live participants and 43 views), likely attributed to decreases in engagement throughout the project, or due to relevancy, as not all gardeners engage in produce preservation. At the end of the project, 224 participants completed questions from both surveys enabling an evaluation of knowledge gained. Overall, a positive increase in mean scores was measured across all questions, indicating that participants gained knowledge from the Extension programing provided. The largest knowledge increases were observed for pest-management questions, ranging from 6% to 20%. Most other questions had an increase of 1% to 8%, except those pertaining to knowledge about the use of canning and freezing methods, and food-safety practices for preservation, with 16% and 13% increases, respectively. The largest differences in confidence levels between pre- and post-test responses were found in questions about implementing control strategies for garden pests, using eco-friendly pest management methods, and reducing food waste, for which “very confident” responses changed from 10% to 82%, 14% to 76%, and 11% to 41%, respectively. Similarly, for all three questions, “not very confident” responses decreased from an average of 12% to 0%. However, there was a shift in confidence for a question regarding food-safety practices for preservation, with “very confident” responses decreasing from 57% to 35% and “not very confident” responses increasing from 0.5% to 5%. This suggests participants may have overestimated their knowledge initially. Our findings demonstrate the positive impact of Extension education on gardening-related knowledge and highlight the value of collaboration between university researchers, Extension faculty, and stakeholders as citizen scientists.
Speakers
CG

Celina Gomez

Purdue University
Co-authors
CH

Cynthia Haynes

Iowa State University
KM

Karen Mitchell

Purdue University
NA
MF

Michael Fidler

Purdue University
NB

Natalie Bumgarner

University of Tennessee
Friday September 27, 2024 10:00am - 10:15am HST
South Pacific 1

10:00am HST

FLOR 3 - Multiple Foliar Applications of Ethephon for Growth Control of Lantana Camara
Friday September 27, 2024 10:00am - 10:15am HST
Lantana (Lantana camara) is a popular annual bedding plant among consumers because it is heat tolerant and attracts pollinators with its vibrant and often multi-colored flowers. Greenhouse growers commonly apply plant growth regulators (PGRs) to control lantana growth and produce a compact, well-branched, and flower. Introduction of new lantana cultivars instigates review of previously known PGR recommendations. As such, the objective of this study was to evaluate the effectiveness of multiple foliar spray applications of ethephon [(2-chloroethyl) phosphonic acid] to control growth and stimulate branching of lantana ‘Bandana Red’. Unrooted cuttings of lantana were received from a commercial propagator and stuck into 105-cell plug trays (30-mL individual cell) filled with a propagation mix. Cuttings were propagated for 35 d under 23 °C air temperature, 24 °C root-zone heating, and a daily light integral of 12 mol·m–2·s–1. Rooted liners were transplanted into individual containers (11.4-cm; 600 mL) filled with a commercial peat-based substrate. Beginning 7 d after transplant, eight single-plant replicants received 1 to 3 foliar spray applications on a weekly basis containing 0 (control; deionized water), 250, 500 or 750 mg·L–1 ethephon. Plants were grown in a glass-glazed greenhouse at 20 °C under ambient daylight supplemented with a photosynthetic photon flux density of ≈125 µmol·m–2·s–1 delivered from LED arrays from 0600 to 2200 HR (16-h photoperiod) to achieve a daily light integral of 12 mol·m–2·d–1. At 42 d after transplant, plants were destructively harvested, and data collected. In general, multiple foliar spray applications with increasing ethephon concentrations affected lantana plant height, diameter, branch number, and shoot dry weight to different magnitudes. For example, lantana plant height was suppressed by 21% to 39% (12.7 to 9.7 cm) from 250 to 750 mg·L–1 ethephon, respectively, compared to untreated plants and were more compact as applications increased. Plant diameter decreased by 13% to 19% (25.5 to 23.7cm) compared to untreated plants as concentration increased from 250 to 750 mg·L–1, respectively, and as spray applications increased. A similar trend was observed for branch number and shoot dry weight. Overall, multiple foliar spray applications of 250 to 750 mg·L–1 ethephon can control the growth of lantana ‘Bandana Red’; however, growers will need to conduct in-house trials to evaluate the level of control desired. Further studies investigating the effects of multiple foliar spray applications with increasing concentrations of ethephon on additional lantana cultivars are warranted.
Moderator
LW

Lark Wuetcher

The Ohio State University
Co-authors
GO

Garrett Owen

The Ohio State University
Friday September 27, 2024 10:00am - 10:15am HST
Kahili

10:00am HST

GG 3 - Fine mapping of Linkage Group 7 (LG7) Eastern Filbert Blight (EFB) Resistance in Hazelnut
Friday September 27, 2024 10:00am - 10:15am HST
Eastern filbert blight (EFB) disease caused by the fungal pathogen Anisogramma anomala (Peck) E. Müller is a major threat to Oregon’s hazelnut (Corylus avellana) industry. The Oregon State University (OSU) hazelnut breeding program has used ‘Gasaway’ as a source of resistance in many releases. Cultivars with ‘Gasaway’ resistance mapped to linkage group 6 (LG6) including ‘Jefferson’ and ‘McDonald’ have been extensively planted throughout Oregon’s Willamette Valley over the past decade. However ,‘Jefferson’ and ‘McDonald’ have exhibited small cankers in commercial orchards under high disease pressure. In New Jersey, cultivars with ‘Gasaway’ resistance develop large cankers. Thus, there are concerns about the long-term durability of ‘Gasaway’ resistance and the sustainability of Oregon’s hazelnut industry. The disease is also a main limiting factor to commercial hazelnut production in the eastern USA. New sources of resistance would be interesting, and a few major resistance genes have been mapped to LG7. Four populations were developed for fine mapping the LG7 resistance region using the ‘Ratoli’ (from Spain) and OSU 1166.123 (from Sochi, Russia) resistance sources. SSRs narrowed the resistance region to < 20 cM, and recombinant individuals were identified using 4-5 SSR loci within the region. Recombinants were inoculated with Anisogramma anomala in the greenhouse and in the field, and disease was evaluated 18 months later. A set of 22 new SSR markers were developed from di- and tri-nucleotide repeats between the flanking markers in the ‘Jefferson’ genome (v4). SSR markers were characterized using a diversity panel of 50 hazelnut accessions. To develop KASP/PACE primers for SNPs in the region, an initial set of 3000 SNPs was reduced to 100 using a SNP array. High density genetic linkage maps with new SSR and KASP markers were constructed for all four mapping populations. The results of this study will aid marker-assisted selection and the breeding of EFB-resistant cultivars with these new sources, and facilitate the pyramiding of R-genes in a single clonal selection for more durable resistance.
Speakers
RM

Rion Mooneyham

Oregon State University
Co-authors
JS

Jacob Snelling

Oregon State
NA
SM

Shawn Mehlenbacher

Oregon State University
Friday September 27, 2024 10:00am - 10:15am HST
Coral 1

10:00am HST

ORGH 3 - Biostimulants Promoted Onion Plant Growth and Helped Mitigate Drought Stress During the Seedling Stage
Friday September 27, 2024 10:00am - 10:15am HST
Climate change and global warming are increasing the frequency of drought incidents, which negatively impact crop production. Onion is one of the major vegetable crops produced in Texas, which requires a long growth period and prone to drought stress as it has shallow roots and needs frequent irrigation. Plant biostimulants may offer a potential solution to mitigate drought stress in onion production. This study investigated the effect of different biostimulants (no application as control, Kelpak, Spectrum DS, MycoApply, and Tribus Continuum) on onion seedling growth under well-watered and drought stressed (50-60% field capacity) conditions. Results showed that there was no significant interaction between biostimulants and drought stress on most of the parameters we collected. All biostimulants significantly increased shoot weight, leaf area, plant height, and root weight compared to the control. Notably, Spectrum DS, MycoApply, and Kelpak specifically enhanced root morphology by increasing root length, root area, and root volume compared to the control. But the application of biostimulants didn’t significantly affect average root diameter or the number of root tips. Drought stress significantly reduced the growth of onion seedlings across all measured parameters, except for the number of root tips, compared to the well-watered group. While drought stress caused a 36.9% decrease in shoot fresh weight, application of Kelpak, Spectrum DS, MycoApply, and Tribus Continuum increased shoot fresh weight by 29.8 to 34.9%, partly offsetting the growth reduction and alleviating the stress experienced by the seedlings. In conclusion, the application of the investigated biostimulants shows promise for enhancing drought tolerance in onion seedlings.
Speakers
avatar for Qianwen Zhang

Qianwen Zhang

Assistant Professor, Mississippi State University
I am a researcher investigating the synergy between organic practices, biostimulants, controlled environment agriculture, and hydroponics to develop sustainable horticultural solutions that enhance human nutrition.
Co-authors
GN

Genhua Niu

Texas A
JM

Joseph Masabni

Extension Vegetable Specialist, Texas A
NA
JL

Jun Liu

Texas A
NA
Friday September 27, 2024 10:00am - 10:15am HST
South Pacific 3

10:00am HST

TROP - Maturity stage at harvest modulates fruit softening and quality of jackfruit
Friday September 27, 2024 10:00am - 10:15am HST
The maturity stage at harvest influences the postharvest quality and storage life of fruit. Harvesting jackfruit (Artocarpus heterophyllus Lam.) at the optimum maturity stage is more important due to the very large size of the fruit. Therefore, the present investigation was conducted to determine the impact of four different maturity stages on physicochemical parameters and fruit-softening enzymes in two jackfruit genotypes (Accession 242 and Accession 341). Fruit for the initial three stages were harvested at 10 days intervals commencing 90 days after flowering (DAF), while fruit for the final stage were harvested based on traditional maturity parameters (142 and 153 DAF) in Accession 341 and Accession 242 respectively. Results indicated an increase in fruit size, seed and bulb weight with the advancement of fruit maturity in both accessions. Moreover, there was a concurrent decline in spine density and an increase in spine flatness with the progression of fruit maturity. Whilst pulp percentage increased, there was a decrease in rag and core percentage at advanced maturity stages. However, peel and seed percentage were not influenced significantly by the advancement of fruit maturity. Additionally, there was a decrease in L* value with a concomitant increase in a*, b*, and C* values of the bulb with the advancement of fruit maturity. In both accessions, bulb firmness, and moisture content were highest in fruit harvested at 90 DAF. The decline in bulb firmness was associated with higher activities of polygalacturonase, pectin methyl esterase, cellulase, and pectate lyase. In both accessions, soluble solid content (SSC), DPPH radical scavenging activity, total flavonoids, and ascorbic acid content were higher in fruit harvested during the last stages of maturity while titratable acidity and total phenolics content were comparatively lower in advanced maturity stages. These findings highlight that the earlier stages (90 and 120 DAF) are suitable as meat alternatives due to better texture, while the most favourable stages for fresh consumption are 142 ± 4.7 and 153 ± 5.7 DAF in ‘Accession 341’ and ‘Accession 242’ due to better colour, higher pulp percentage, higher SSC and antioxidant activity, respectively.
Speakers
ZS

Zora Singh

Foundation Professor Horticultural Science, Edith Cowan University
Zora Singh is a Foundation Professor Horticultural Science in the School of Science with noteworthy expertise in Production technology and Postharvest physiology of fresh horticultural produce, undergraduate teaching and research training to domestic and international MSc and PhD... Read More →
Co-authors
AW

Andrew Woodward

Edith Cowan University
NA
EA

Eben Afrifa-Yamoah

Edith Cowan University
NA
HM

Hafiz Muhammad Shoaib Shah

Edith Cowan University
NA
JK

Jashanpreet Kaur

Edith Cowan University
MS

Muhammad Sohail Mazhar

Department of Industry, Tourism and Trade
NA
Friday September 27, 2024 10:00am - 10:15am HST
Lehua Suite

10:00am HST

VCM 6 - Field-Based Remediation Strategies for Groundwater Nitrogen Contamination
Friday September 27, 2024 10:00am - 10:15am HST
Agricultural pollutants are commonly detected in Wisconsin groundwater samples, particularly in areas with coarse-textured soils and high input agriculture. Practical and effective techniques are needed to reduce contaminants in agricultural leachate to protect human health and the nearby environment. Organic soil additives may be able to capture excess nitrogen fertilizer in the soil and prevent groundwater contamination with minimal grower expense. Five soil additives were tested in soil columns for nitrogen fertilizer capture ability. Two biochar treatments, two papermill waste treatments, and one humic acid treatment was tested against an untreated control. Leachate volume remained constant among treatments, but biochar and papermill waste treatments reduced nitrogen content in leachate (up to 8.5% and 35%, respectively). Humic acid was ineffective at reducing nitrogen content in leachate in an abiotic system, prompting a second soil column experiment currently underway that includes live potato plants. Intercropping systems may also be able to reduce agricultural pollutants in groundwater. Potatoes were intercropped with adjacent strips of fall-planted winter rye, spring-planted winter rye, and spring-planted yellow mustard to investigate the effects of companion crops on potato yield compared to a monoculture potato control plot. Intercropping did not impact potato yield or size distribution compared to monoculture potato. A second intercropping study was designed to explore potato yield when companion crops were planted directly in the furrow between each potato row. Treatments included a spring-planted winter rye and a spring-planted yellow mustard, seeded at three intervals post hilling, with nitrogen fertilizer banded over the potato row or conventionally broadcast. Neither intercropping nor fertilizer application method affected potato yield. Further research is underway to test intercropping systems in other high-nitrogen vegetable crops such as sweet corn.
Speakers
ES

Emma Schmidt

University of Wisconsin- Madison
NA
Co-authors
DH

Daniel Heider

University of Wisconsin-Madison
NA
JS

Jacklyn Slivicke

University of Wisconsin-Madison
NA
JC

Jed Colquhoun

University of Wisconsin
Friday September 27, 2024 10:00am - 10:15am HST
South Pacific 2

10:00am HST

WCPM 4 - Can Multi-species Cover Crops and Beneficial Microbes be Utilized for Soil Borne Pathogen Management in Watermelon?
Friday September 27, 2024 10:00am - 10:15am HST
Watermelon is highly susceptible to soil borne pathogens, typically Fusarium oxysporum sp. Niveum (FON) that can lead to a yield loss of upto 60-80%. Out of the four pathogenic races of FON, race 2 is more prevalent in the Southeastern US on more than 60% of watermelon fields. Cover crops are known for improving soil health, diversity, and abundance of microorganisms, and reported to decrease Fusarium wilt (FW) disease severity by up to 20-60%. However, previous studies have only evaluated single species cover crops for its impact on FW in watermelon whereas for ecosystems services, multi-species cover crops are recommended. A greenhouse and field study were conducted with aims to determine the effects of multi-species cover crops and beneficial microbes in controlling FW in watermelon. The cover crop mixtures included in the studies were, mixture A: rye, oat, Austrian winter pea, crimson clover, hairy vetch; mixture B: oat, wheat, crimson clover, radish, turnip. The field study was conducted at two locations in upper coastal region of South Carolina. Periodic cover crop biomass was taken. At location one cover crop mixture A accumulated a fresh biomass of 1017.50 tons/ha as compared to mixture B (907.16 tons/ha), at 97 days after planting. On the other hand, at second field site, mixture A accumulated fresh biomass of (349.6.4 tons/ha) and fresh biomass weight of mixture B was (153.59 tons/ha) at 120 days after planting. This could be due to more sandy and poor soil conditions at second field site. Further we will evaluate the impact of different treatments on FW disease severity index, watermelon fruit yield and fruit quality parameters.
Speakers
SK

Sukhman Kaur

Clemson University
Co-authors
BJ

Bhupinder Jatana

Clemson University
TS

Tom Sanders III

Clemson University
NA
Friday September 27, 2024 10:00am - 10:15am HST
South Pacific 4

10:15am HST

CE 7 - Increasing Nutrient Solution Electrical Conductivity Increases Vegetative Growth of Strawberry
Friday September 27, 2024 10:15am - 10:30am HST
Established guidelines for electrical conductivity (EC) for strawberry (Fragaria ×ananassa) fruit production exist for plants grown in soilless substrates. However, EC recommendations for strawberry mother plants may differ when the goal is prolific runnering instead of flowering and fruiting. Our objective was to evaluate the impact of EC concentration strawberry runner and daughter number. Strawberry ‘Monterey’ were grown in a greenhouse in 19.1-cm diameter pots filled with a soilless substrate (50 perlite : 25 coco coir : 25 peat). To formulate the EC treatments, all components of a strawberry nutrient solution (Yamazaki) increased equally, which corresponded to nitrogen (N) concentrations of 50, 100, 150, 200, 300, and 400 mg·L-1 N. After adding 0.8 mM potassium bicarbonate as a buffer and adjusting pH to 5.7, the final nutrient solution EC values were 0.9, 1.6, 2.3, 2.8, 3.9, and 4.9 mS·cm-1. After 12 weeks of treatment, runner and daughter plant number, morphological assessments, and mother plant leaf burn index were evaluated. The qualitative assessment of leaf burn utilized a 1 to 5 scale (1 = no tip burn; 2 = mild, margins of ≥ 3 leaves; 3 = moderate, necrosis on at least half of ≥ 3 leaves; 4 = moderate to severe, complete necrosis on ≥ 3 leaves; and 5 = severe, complete necrosis on ≥ 4 leaves and necrosis of daughter plants). Leaf burn values ranged from 1.6 ± 0.2 (± SE) in the 50 mg·L-1 N treatment to 5.0 ± 0.0 in the 400 mg·L-1 N treatment. Runner number exhibited a quadratic response and ranged from 2 ± 0 at 50 mg·L-1 N to 7 ± 1 at 300 mg·L-1 N. Daughter plant number also exhibited a quadratic response. It increased from 14 ± 3 at 50 mg·L-1 N to 44 ± 4 at 200 mg·L-1 N, then declined to 30 ± 13 at 400 mg·L-1 N. Total plant biomass (mother plant, stolons, and daughter plants) exhibited a quadratic relationship. It increased from 23.5 ± 4.0 g at 50 mg·L-1 N to 65.9 ± 7.9 g at 200 mg·L-1 N, then declined to 40.0 ± 5.2 g at 400 mg·L-1 N. Overall, the optimal nutrient solution EC range for strawberry mother plants was 100 to 200 mg·L-1 N (or 1.6 to 2.8 mS·cm-1). In this range, mother plants produced a high number of runners and daughter plants, with minimal leaf burn due to high substrate EC values.
Speakers
EY

Erin Yafuso

United States Department of Agriculture
Co-authors
JB

Jennifer Boldt

United States Department of Agriculture
Friday September 27, 2024 10:15am - 10:30am HST
Nautilus

10:15am HST

CHMG 2 - Using Citizen Science to Evaluate Cultivar Preferences of Compact Tomato Plants
Friday September 27, 2024 10:15am - 10:30am HST
Citizen science can be used as a research method to evaluate consumer preferences in horticulture. In 2023, 300 participants from Indiana, Iowa, and Tennessee were recruited to grow three cultivars of compact tomato (Solanum lycopersicum) plants started from seed or as transplants in an 18-week experiment. The cultivars evaluated were Cocoa, Red Robin, and Micro Tom. After completing a pre-experiment survey to characterize demographics and gardening experience levels, participants were provided with a plant kit containing all materials required to complete the experiment. Participant engagement was maintained using a social-media community page, monthly virtual educational sessions, and frequent email communications. At the end of the experiment, 203 participants had completed the post-experiment survey focused on evaluating cultivar and plant-type preferences. Furthermore, three focus group sessions with six random participants each were conducted to further assess survey responses. Cocoa was the preferred cultivar by 41% of participants, followed by Red Robin at 31%. Cultivar preferences of plants started from seed followed the same trend for appearance, fruit number, and fruit taste. However, growth and appearance of ‘Red Robin’ transplants were ranked higher than ‘Cocoa’. Approximately 70% of participants preferred plants started as transplants compared to those from seed, regardless of cultivar. These preferences were attributed to the higher yield, better growth and perceived fruit taste, and lower maintenance required to use transplants. Overall, 69% of participants reported they would be willing to pay between $1.00 to $7.49 more for a transplant of their favorite cultivar compared to currently available tomato plants at local nurseries. Findings from the focus group sessions indicated participants liked the potential gift-use of these compact cultivars, and their versatility to be used in different gardening spaces such as kitchen countertops or windowsills. Results from this study indicate potential consumers value appearance, fruit yield, and fruit taste when selecting compact tomato cultivars, whereas ease of care and plant growth are more important factors when choosing a plant type.
Speakers
MF

Michael Fidler

Purdue University
Co-authors
CG

Celina Gomez

Purdue University
CH

Cynthia Haynes

Iowa State University
KM

Karen Mitchell

Purdue University
NA
MK

Melinda Knuth

North Carolina State University
NB

Natalie Bumgarner

University of Tennessee
Friday September 27, 2024 10:15am - 10:30am HST
South Pacific 1

10:15am HST

FLOR 3 - Ethephon Substrate Drenches Control Growth of Containerized Annual Bedding Plants and Herbaceous Perennials
Friday September 27, 2024 10:15am - 10:30am HST
Containerized annual bedding plants and herbaceous perennials account for 57% of the 2020 U.S. floriculture market with a reported combined wholesale value of $3.2 billion. To produce high-quality, compact containerized ornamental plants, foliar spray applications and substrate drenches of plant growth regulators (PGRs) are often utilized. Ethephon [(2-chloroethyl) phosphonic acid] is a common PGR used to control growth, stimulate branching, and manipulate flowering, but is only labelled for foliar applications. Therefore, our objective was to evaluate the response of 35 floriculture species drenched with increasing concentrations of ethephon. Annual bedding plants and herbaceous perennials were received as unrooted cuttings and propagated at 23°C under 10 mol·m–2·s–1 for 21 or 28 d, respectively. Plants were transplanted into containers filled with a soilless substrate and grown in a glass-glazed greenhouse at 20°C under 14 mol·m–2·d–1. At 10 d after transplant, eight single-plant replicates received a substrate drench of 296-mL aliquots of solution containing 0 (control; deionized water), 25, 50, 75, 100, or 200 mg·L–1 ethephon for annuals or 0, 125, 250, 500, 750, or 1,000 mg·L–1 ethephon for herbaceous perennials. Plant growth metrics including height, diameter, shoot and root dry weight were determined 6 weeks after transplant. Time to flower was determined for select species by recording the date of anthesis for each plant. In general, plant height of annual bedding plants and herbaceous perennials were suppressed and shoot and root dry weight reduced as concentrations of ethephon increased. For example, petunia (Petunia × hybrida ‘Flame Red’) drenched with 200 mg·L–1 was ≈40% (5.8 cm) shorter than untreated plants. Similarly, in dahlia (Dahlia × hybrida ‘Dark Red’) height and diameter were decreased by 50% (15.4 cm) and 30% (12.4 cm), respectively as concentrations increased from 0 to 200 mg·L–1. In digiplexis (Digiplexis × hybrida), substrate drenches increasing from 0 to 1,000 mg·L–1 ethephon reduced shoot dry mass by ≈55% (17.1 g). Root dry weight of catmint (Nepeta faassenii) was reduced by 35% (1.54 g) as concentrations increased from 0 to 1,000 mg·L–1. Time to flower was unaffected at all concentrations of the species selected. These growth and development trends were reflected in most of the species evaluated. As such, this research demonstrates that ethephon, if labelled for substrate drenches, provides adequate growth control of floriculture crops.
Speakers
WR

William Rich

The Ohio State University
Co-authors
GO

Garrett Owen

The Ohio State University
Friday September 27, 2024 10:15am - 10:30am HST
Kahili

10:15am HST

GG 3 - Estimation of Breeding Values to Improve Kernel Weight in Almond (Prunus dulcis)
Friday September 27, 2024 10:15am - 10:30am HST
Improving nut and kernel quality traits is a high priority in almond breeding programs around the world. Almond has a long juvenile period and phenotypic selection for nut and kernel traits can only be conducted after three years from planting. In early stages of planting, individuals with desirable nut and kernel traits can be identified by marker-trait associations (MTAs) using molecular markers. Currently, MTAs are identified by quantitative trait locus (QTL) mapping using progeny from bi-parental crosses or association mapping panels. However, the efforts of identifying MTAs using current QTL detection methods are hampered either by unavailability of genomic information or required genetic linkage maps. In addition, most kernel traits have polygenic inheritance, and many genes and genomic regions affect genetic variations. In crop research, genomic selection would provide promising approach to accelerate the genetic gains and reduce the length of breeding cycle. Yet, application of genomic selection in almond breeding and research is limited. We present results demonstrating the predictive ability of whole-genome and pedigree-based models to identify elite candidate parents for almond kernel weight. In this work, we used ancestral pedigree and phenotypic data from 13,000 progeny that were derived from 57 parents and 291 families. Ancestral pedigrees were recorded from the available literature from the almond breeding programs in USA, Spain, Italy, France, and Australia. Average kernel weight was obtained for each progeny tree from 30 nuts. All parents were resequenced using whole-genome sequencing at a depth of 15x. Over 80k high quality, independent single-nucleotide polymorphisms were used to construct realised genomic relationship matrix and linkage disequilibrium (LD) regions were used to compute LD weights. Genomic best linear unbiased prediction (GBULP) using Asreml-R was used to predict genomic estimated breeding values (GEBV). Pedigree model derived from linear mixed model was used to predict individual tree effects (PEBV) to validate the predicted GEBVs. EBVs were compared using Pearson correlation coefficient (r) and elite candidate parents were selected based on the selection index. For kernel weight, both pedigree and genomic models resulted similar EBVs, and r was 0.97. A high level of correlation in EBVs obtained from two methods indicates the suitability of these models in estimating BVs for future predictions. Predicted elite candidate parents from this study can reduce the conventional breeding cycle of almond by 6 years. The constructed models mainly represent Australian context and multi-environmental trials are required to identify the broader applicability of these models.
Speakers
SG

Shashi Goonetilleke

The University of Queensland
Co-authors
CH

Craig Hardner

The University of Queensland
NA
MW

Michelle Wirthensohn

The University of Adelaide
NA
Friday September 27, 2024 10:15am - 10:30am HST
Coral 1

10:15am HST

ORGH 3 - Effluent of the Anaerobic Digestion of Food Waste as a Biofertilizer for Red Cabbage
Friday September 27, 2024 10:15am - 10:30am HST
Food and farm waste processed by anaerobic digestion (AD) generates a nutrient-rich digestate suitable for use as a biofertilizer. Small-scale AD systems production of biofertilizer offer an on-site solution accessible to individual households and small horticultural producers. Unlike common and more complex AD solutions, small-scale systems do not require extensive management or infrastructure investments. In 2022, we investigated the nutrient content and usability of digestate from two small-scale biodigester models: A commercially built digester with a 1,200 L digester tank, and a prototype we designed with a 114 L capacity. Locally sourced fresh raw cow milk served as inoculum. Over a span of 16 weeks, 12 randomly selected households in Bozeman, Montana, tested the two digester models, feeding them with the food waste they generated. Six of the households received the commercial model, and six tested the prototype. Digestate samples were collected biweekly to analyze their chemical properties and potential as a biofertilizer. After 16 weeks, we blended all digestate, taking equal parts from all household samples, and tested it in a greenhouse study as a fertilizer for red cabbage (Brassica oleracea L. Capitata Group) seedlings. In addition to a control treatment where no biofertilizer was used, we applied 40 ml of biofertilizer per plant in a “high dose treatment” and 20 ml biofertilizer per plant in a “low dose treatment.” Each treatment involved 50 cabbage plants growing individually in trays of 10 cm diameter. On a weekly interval, the biofertilizer was sprayed on the substrate, with amounts varying by treatment. The substrate consisted of loam soil, washed sand, Canadian sphagnum peat moss, perlite, vermiculite, and dolomitic lime. Seedlings were irrigated manually every second day. To ensure sufficient nitrogen supply, all three treatments received an initial application of 40 mL of fish emulsion per cabbage plant. No pest or disease management practices were implemented. After 30 days, all plants were harvested, and their aboveground dry biomass was measured. A trend towards higher aboveground dry biomass in the "high biofertilizer dose" treatment compared to the "low biofertilizer dose" and control treatments was observed. Additionally, the aboveground biomass underwent nutrient content analysis, revealing a tendency towards the highest potassium content in the "high dose treatment." This study showed that household food waste processed through small-scale AD systems generates valuable biofertilizer that can help manage crops’ nutrient needs.
Speakers
avatar for Roland Ebel

Roland Ebel

Assistant Professor, Montana State University
Roland Ebel has a Ph.D. in Organic Farming, granted by the University of Natural Resources and Life Sciences, Vienna. His dissertation project on the diversification if organic tomato systems was conducted in Gran Canaria, Spain. From 2008 to 2014, Dr. Ebel was a member of the Agroecology... Read More →
Friday September 27, 2024 10:15am - 10:30am HST
South Pacific 3

10:15am HST

TROP - Growing papaya in Mississippi
Friday September 27, 2024 10:15am - 10:30am HST
Papaya (Carica papaya) is an herbaceous perennial plant native to the tropical Americas. It thrives in tropical and subtropical climates. While the United States is the world’s largest papaya importer, it also cultivates a modest number of papayas, primarily in Hawaii, California, Texas, and Florida. The subtropical climate in Mississippi offers favorable conditions for papaya cultivation. However, frosts in late fall or early spring could pose threats to both plants and fruits. Appropriate cultivar selection and management strategies are critical for successful papaya production in MS. Currently, limited information is available on growing papayas in MS. The objective of this study was to investigate the potential of growing papaya as an alternative crop for specialty crop growers in MS. Preliminary data suggest that papaya plants can grow well in Mississippi. Different cultivars exhibited variations in plant size and vigor. Plants produced papaya fruits with variations in fruit number, size, and shape, as well as timing to fruiting among different cultivars. However, the relatively shorter growing season in MS compared to tropical climates resulted in insufficient time for most fruits to ripen before the onset of frost in late fall. Further research will involve evaluating additional cultivars, adjusting production schedules, employing season extension techniques, and assessing economic feasibility.
Speakers
GB

Guihong Bi

Mississippi State University
Co-authors
JL

Jacob Land

Mississippi State University
NA
TB

Taylor Blaise

Mississippi State University
NA
TL

Tongyin Li

Mississippi State University
NA
Friday September 27, 2024 10:15am - 10:30am HST
Lehua Suite

10:15am HST

VCM 6 - Can Healthy Soil Make Healthy People? Investigating The Impact Of Soil Biota On Micronutrient Uptake In Vegetable Crops
Friday September 27, 2024 10:15am - 10:30am HST
The health of humans and ecosystems are closely interlinked, therefore fostering healthy soils may aid in addressing micronutrient deficiencies. Healthy soils are active with diverse microbial and mesofauna communities that carry out soil processes that are essential for crop growth and development. A greenhouse experiment was conducted to investigate the effect of soil mesofauna on micronutrient content in vegetable crops and determine if plant root structure or shifts in soil microbial community composition (relative pathogen abundance) impact these affects. Crop species (snap beans and beets), Collembola (Isotomiella minor) abundance (none, low, or high), and microbial community composition (native community and pathogen-dense community) treatments were imposed and replicated five times. The soil treatments were prepared by sterilizing soil and inoculating the soil with the two different microbial communities. The inoculated soil was placed in pots and one cup of compost was mixed into the top 5 cm. Snap beans and beets were planted at a depth of 2.5 cm and 0.25 cm, respectively. The Collembola treatments (none, 100 Collembola, 200 Collembola) were then added to the appropriate pots. Weekly checks were conducted to monitor plant health and growth. Once each crop reached maturity (approximately 60 days), a destructive harvest was conducted. Crop biomass and marketable yield fresh weights were recorded and I. minor abundance was verified at the harvest. Crop biomass samples were frozen for later analysis of minerals relevant to human health including essential nutrients (e.g., calcium, sodium, magnesium, potassium, iron, and zinc) and heavy metals (e.g., lead, cadmium, and arsenic). Minerals were extracted via microwave digestion in nitric acid and quantified via ICP-MS. We hypothesized that the concentration of micronutrients in the vegetables will increase as I. minor abundance increases, and that the I. minor will have a greater effect on the snap bean compared to the beets due to the greater root surface area. Additionally, we conjectured that a pathogen-dense microbial community will diminish the effects of I. minor on micronutrient uptake, since greater pathogen presence would likely decrease their direct interactions with crop roots. We found that the addition of I. minor enhanced crop growth regardless of soil microbial community composition. The beets were more sensitive to changes in soil microbial community composition compared to the snap beans. Our findings illustrate the importance of healthy soil biological communities for quality vegetable production.
Speakers
AJ

Ashley Jernigan

Assistant Professor, Virginia Tech
Co-authors
DC

Dennis Cladis

Virginia Tech
NA
Friday September 27, 2024 10:15am - 10:30am HST
South Pacific 2

10:15am HST

VSF 5 - Two Years, Three Genotypes, and Two Locations: Fruit Quality of Native and Cultivated Aroniaberry Grown in Georgia.
Friday September 27, 2024 10:15am - 10:30am HST
Aroniaberry or chokeberry (Aronia sp., Rosaceae) is an attractive new native fruit crop. Native to eastern and central United States, this deciduous tree-like shrub produces berries with one of the highest concentrations of anthocyanins compared to other fruits. Bred for northern climates, A. ‘Viking’ is the most popular fruit cultivar. Fruit production and quality of A. ‘Viking’, Red Chokeberry (A. arbutifolia), and black chokeberry (A. melanocarpa) was evaluated during the 2022 and 2023 growing seasons, in two locations in the state of Georgia: Blairsville (Zone 7a, Blue Ridge region) and Griffin (Zone 8a, Piedmont region). At both locations, 15 two-year old plants of each genotype were planted in 2021. All genotypes increased their yields between growing seasons (2022 to 2023) but the increment was much higher, and plants had higher yields in Blairsville. A. ‘Viking’ performed poorly in Griffin in 2022 (38.33 g and 119.4 average berries /plant) compared to plants in Blairsville (184.83 g and 237 average berries /plant); in 2023, Blairsville yields were 705.58 g and 1308 average berries /plant, but yields were almost zero in Griffin. A similar trend was observed in A. melanocarpa, with higher yields in Blairsville in the first year and no berry production in Griffin during the second year. A. melanocarpa was the genotype with the biggest increment in yield from 30.62 g and 21 average berries/plant in 2022 to 1111.41 g and 1594.95 average berries /plant in 2023 (Blairsville). A. arbutifolia had better yields in Blairsville compared to Griffin, but plants produced berries at both locations during both years. In terms of fruit quality, A. ‘Viking’ berries were tougher and with a stronger skin in Griffin, and there were no significant differences in texture from 2022 to 2023 in Blairsville. A. melanocarpa berries had similar texture and skin strength in both years. A. arbutifolia texture was similar in both locations in 2023, but in 2022 Griffin plants produced tougher fruit with stronger skin. Plants in Blairsville produced sweeter fruit compared to Griffin, across all genotypes.
Speakers
avatar for Leynar Leyton

Leynar Leyton

Assistant Professor, University of Florida
Co-authors
BP

Bodie Pennisi

University of Georgia
NA
CR

Carol Robacker

University of Georgia
NA
Friday September 27, 2024 10:15am - 10:30am HST
Coral 3

10:15am HST

WCPM 4 - Evaluation of Celery Breeding Lines and Commercial Cultivars for Resistance to Fusarium oxysporum f.sp. apii Race 2 and Race 4
Friday September 27, 2024 10:15am - 10:30am HST
Fusarium wilt of celery, caused by the soil-borne pathogen Fusarium oxysporum f. sp. apii (Foa), has been a persistent challenge for celery growers in California. Two races of the pathogen are documented in California. Foa race 2 was described in the 1970s and is widespread throughout celery-growing regions of California, typically causing yellowing and stunting of established plants, resulting in failure to produce marketable heads. Foa race 4 was identified in Ventura County in 2013 and by 2022 had displaced race 2 as the predominant race causing celery losses in Ventura County. Foa race 4 is more aggressive than race 2, often causing plant stunting and death within weeks after planting, particularly if soil temperature is 22ºC or higher. In support of celery breeding programs, USDA and University of California developed a collaboration to conduct resistance evaluation field trials. Trials were conducted in two coastal California locations naturally infested with Foa in 2022 and 2023: Santa Maria (race 2) and Camarillo (race 4). Cultivars and breeding lines from private companies and public germplasm collections were evaluated in replicated field plots. Plant mortality was assessed, and soil temperature was recorded during the growing season. At harvest, disease severity of internal symptoms of Fusarium wilt were scored from 0 (no visible symptoms) to 5 (severe crown decay) for a subset of plants from each plot. Each celery entry was assessed for petiole length, weight, petiole greenness, cracking, bolting, ribbiness, pithiness, and suckering for a subset of plants from each plot. At Santa Maria in 2022, there was minimal plant mortality, but most entries appeared susceptible with disease severity scores ranging from 2.0-3.6, indicating vascular symptoms in roots and crowns. Many entries did not produce marketable celery due to stunting. Entries exhibiting the most tolerance to Foa race 2 had disease severity scores of 0.1-0.7 and produced the heaviest stalks with the longest petioles. At Camarillo in 2022, daily mean air temperatures during the two weeks after planting were 24 to 27ºC, likely promoting rapid disease development of Foa race 4 and severe early decline in susceptible entries. Six weeks after planting, 23 of 42 entrees exhibited 80-100% plant mortality. However, five entries had disease severity scores of 1.0-1.5 and less than 15% mortality. These more tolerant lines produced marketable celery. These results contribute to the development of Foa-resistant breeding lines and inform growers about the performance of cultivars in local conditions.
Speakers
CG

Christopher Greer

University of California
Co-authors
AP

Alexander Putman

University of California, Riverside
NA
OD

Oleg Daugovish

University of California Cooperative Extension
RE

Renee Eriksen

USDA Agricultural Research Service
NA
Friday September 27, 2024 10:15am - 10:30am HST
South Pacific 4

10:30am HST

CE 7 - Impact of Artificial Chilling on Yields of Indoor-Propagated Strawberry Plants in California, Florida, and North Carolina
Friday September 27, 2024 10:30am - 10:45am HST
Unavailability of pathogen-free strawberry propagules in commercial quantities necessitates the development of a novel completely indoor precision propagation technology for the crop, which also seeks to reduce dependence on soil fumigants including methyl bromide. Artificial chilling of plug plants could also enhance transplant vigor, flowering, and yield of strawberry. Under this novel technology, strawberry tips which consisted of five short day (SD) cultivars (Fronteras, Camarosa, Chandler, Sensation and Brilliance) and one long day (LD) cultivar (Monterey) were collected from tissue cultured mother plants. Plants were propagated under completely controlled environment (CE) conditions in a plant factory. Strawberry daughter plants were rooted in 50 cc trays filled with a commercial substrate and were arranged in the controlled environment under 90 – 100 % humidity, 27 °C temperature, 80 – 100 µmol m-2 s-1 light (LED), 18 hours photoperiod, and fertigated using the ebb and flow technique for 28 days. Our hypothesis was that artificial chilling will improve plant vigor and yield of CE-propagated strawberry transplants. We therefore assessed the impact of 350 – 450 hours of artificial chilling on the plant performance and yield of the transplants in four different locations in the US. Monterey, Brilliance, and Sensation cultivars received 350 hours of chilling while Fronteras, Chandler, and Camarosa cultivars were chilled for 450 hours. Strawberry plug plants (chilled and no-chill) were planted in replicated field trials in California, Florida, and North Carolina. Camarosa and Chandler cultivars were transplanted in North Carolina, Fronteras in Southern California, Monterey in Central California, while Brilliance and Sensation were transplanted in Florida. Preliminary results show improved vigor and yield from chilled plants in Florida and North Carolina field trials, while no differences were observed in California. Final results of the study will be shared during the conference.
Speakers
avatar for Ibraheem Olamide Olasupo

Ibraheem Olamide Olasupo

Postdoctoral Research Scholar, North Carolina State University
Co-authors
CS

Calyssa Stevenson

North Carolina State University
NA
GH

Gerald Holmes

Cal Poly San Luis Obispo
NA
GF

Gina Fernandez

North Carolina State University
NA
MH

Mark Hoffmann

North Carolina State University
NA
OD

Oleg Daugovish

University of California Cooperative Extension
RH

Ricardo Hernandez

North Carolina State University
NA
SS

Samantha Simard

Cal Poly- San Luis Obispo
SA

Shinsuke Agehara

University of Florida
Friday September 27, 2024 10:30am - 10:45am HST
Nautilus

10:30am HST

CHMG 2 - Extension Master Gardeners and Pollinator Research: The Challenges and Benefits
Friday September 27, 2024 10:30am - 10:45am HST
Extension Master Gardeners (EMGs) have participated in a variety of citizen science projects providing new knowledge. This knowledge acquisition may not occur without the assistance of EMGs. Research projects that are focused on consumer horticulture challenges are not typically given a high priority by those who financially support scientific research in consumer horticulture. Therefore, researchers turn to EMGs as citizen scientists to assist with consumer horticulture research. In 2022, Ohio State University partnered with the Cincinnati Zoo and Botanic Garden, Dawes Arboretum, and Ohio EMGs to evaluate 10 cultivars of native plants to determine if they were attractive to pollinators. EMGs were tapped to monitor the cultivars and collect data on abundance and diversity of species. Thirteen Ohio counties with EMG programs were involved in this research along with the partners. The first year of data collection was a pilot year and the second year was the first year for data analysis. In this session you will learn about the steps involved in this research project as well as the challenges addressed and benefits to both the EMGs and the consumer. You will also learn about the results of the research.
Speakers
avatar for Pam Bennett

Pam Bennett

State Master Gardener Program Director, Associate Professor, Ohio State University
Friday September 27, 2024 10:30am - 10:45am HST
South Pacific 1

10:30am HST

FLOR 3 - Microbial Communities in the Vertical Profile of a Container Substrate
Friday September 27, 2024 10:30am - 10:45am HST
A moisture gradient exists in containers filled with soilless substrates where the substrate is wetter at the bottom of the container and becomes drier towards the top of the container. This moisture gradient affects other substrate chemical properties and therefore may affect biological properties including the microbial communities present. Microbial communities in soilless substrates have only recently been studied and little is known about their uniformity throughout the container. This research aimed to evaluate how the bacterial and fungal portions of the microbial community may change along the vertical profile of a container substrate. A substrate was mixed that consisted of manure compost, peat moss, and perlite (20:65:15 v/v) and planted with a single sunflower seedling. After 0, 3, and 6 weeks in a greenhouse environment, samples of soilless substrate from the top, middle, and bottom of the container (approx. 4.3 cm depth for each layer) were collected for DNA extraction. Bacterial and fungal communities were characterized by sequencing PCR amplified 16s rRNA genes and ITS regions, respectively. We found that the phyla Pseudomonadota, Bacteriodota, and Ascomycota were present throughout the container profile in all three layers. However, bacterial genera Paucibacter, Pseudomonas, and Iodophanus, and fungal genera Cercophora and Mortierella differed in abundance within each layer. Pseudomonas tolerant to negative abiotic factors were greater in the bottom layer after 6 weeks. Likewise, Coprinellus , responsible for lignin and cellulose degradation, was also present only in the bottom layer. The diversity of bacterial communities differed between layers, with the greatest in the middle and the lowest in the top layer. The percentages of all bacterial amplicon sequence variants (ASVs) that were shared among the three layers at 3 and 6 weeks were only 16% and 28%, respectively. The diversity of fungal communities was less affected by layer and time, but the percentages of shared fungal ASVs among layers were still only 27% and 28% at 3 and 6 weeks, respectively. In consequence, it is necessary to consider sampling technique and location when collecting a DNA sample from a container substrate.
Speakers
SV

Silvia Valles Ramirez

Ohio State University
NA
Co-authors
FM

Frederick Michel

Ohio State University
NA
JP

Jelmer Poelstra

Ohio State University
NA
Friday September 27, 2024 10:30am - 10:45am HST
Kahili

10:30am HST

GG 3 - Alternative RNA Splicing Associated with Pecan Dichogamy
Friday September 27, 2024 10:30am - 10:45am HST
Pecan (Carya illinoinensis), a North American native nut crop, exhibits two distinct flowering habits where male and female flowering occur at separate times. Trees that shed pollen before their pistillate flowers become receptive are classified as protandrous or type 1 (recessive homozygous, pp), while those with pistillate flowers receptive before pollen shed are protogynous or type 2 (dominant heterozygous, PP/Pp). Establishing commercial pecan orchards requires planting both types of pecan cultivars to ensure optimal pollination for maximum production. To investigate critical genes associated with pecan heterodichogamous flowering, we collected tissues from four stages (dormant buds, swollen buds, immature catkins, and immature pistils) of three genotypes (PP, Pp, and pp). Paired-end RNA sequencing at 125/150 bp read lengths was conducted on an Illumina platform. Clean and unique reads were mapped to an annotated 'Pawnee’ reference genome. Out of 32,267 annotated genes, over 5,000 (~15%) were identified to have alternative splicing events associated with pecan flowering dichogamy. We illustrate by three genes that present significant alternative splicing patterns associated with dichogamy genotypes, distinguishing the pp genotype from PP and Pp genotypes. These genes exhibited 6-18 nucleotide differences in RNA sequence between the pp genotype and PP/Pp genotypes, potentially resulting in an altered protein product with 2-6 amino acid differences between type 1 and type 2 genotypes. This study provides evidence for the prevalence of alternative RNA splicing in the transcription regulation of pecan dichogamy.
Speakers
avatar for Xinwang Wang

Xinwang Wang

Plant Geneticist, USDA ARS
Co-authors
JR

Jennifer Randall

New Mexico State University
NA
JS

Joe Song

New Mexico State University
NA
WC

Warren Chatwin

USDA ARS Southern Plains Agricultural Research Center
NA
YL

Yiyi Li

New Mexico State University
NA
Friday September 27, 2024 10:30am - 10:45am HST
Coral 1

10:30am HST

ORGH 3 - Optimizing the Application of Anaerobic Soil Disinfestation in Organic High Tunnel Vegetable Production Systems
Friday September 27, 2024 10:30am - 10:45am HST
The growth of the U.S. organic vegetable industry is currently limited by the availability of viable and effective solutions for the management of soilborne pests and pathogens. Anaerobic soil disinfestation (ASD) is a pre-planting biological method proposed for the management of a range of soilborne pests and pathogens affecting horticultural crops. As an organic amendment-based approach, ASD is implemented incorporating in the soil an easily degradable carbon (C) source, tarping the soil with plastic mulch, and irrigating the soil to field capacity. The selection of organic amendments suitable as C sources is critical for the efficacy of the treatment and its sustainability. Understanding how the physicochemical properties of alternative amendments may affect the efficacy of the ASD treatment, the soil fertility during and post ASD, and consequently the crop performance is critical. Therefore, a study was conducted on organic-certified land at the Penn State High Tunnel Facility to compare wheat middlings (WM), molasses (M), and soybean meal (SM) and their combination as C sources. Treatments tested included WM, M, SM, WM SM, and M SM applied at the standard rate of 6 Mg/ha of total C, SM0.5 applied to reach the equivalent of 3 Mg/ha of total C, and the untreated controls with (UTC W) and without (UTC) initial irrigation. Three weeks after the ASD treatment, Romaine lettuce was planted as a test crop. Organic amendments tested as C source were characterized by different C:N ratio, ranging between 6.3 (SM) and 57.2 (M). All the amendments tested ensured the achievement of good soil anaerobicity levels. The C:N ratio of the amendments significantly influenced the availability of nitrate-N during and post-ASD, thereby influencing the lettuce crop yield and quality performance. Having the highest C:N ratio, M applied by itself decreased the availability of nitrate-N during and post-ASD. Instead, SM characterized by the lowest C:N ratio, increased the availability of nitrate-N. The availability of N during the growing cycle, determined by the characteristics of the organic amendment and by the ASD treatment influenced the crop yield and nutritional profile. The results of the present study provide new insight for the selection of alternative C sources and the optimization of the ASD treatment in organic protected culture systems.
Speakers
FD

Francesco Di Gioia

Pennsylvania State University
Co-authors
BM

Ben Morrison

Pennsylvania State University
NA
ER

Erin Rosskopf

USDA Agricultural Research Service
NA
FD

Francisco Dini Andreote

Pennsylvania State University
NA
JK

Jason Kaye

Pennsylvania State University
NA
JO

Joe Ono Raphel

Pennsylvania State University
NA
KA

Kathleen Arrington

Pennsylvania State University
NA
RC

Radhika Chalam

Pennsylvania State University
NA
Friday September 27, 2024 10:30am - 10:45am HST
South Pacific 3

10:30am HST

VCM 6 - Optimizing nitrogen fertilizer concentrations in vegetable transplant production
Friday September 27, 2024 10:30am - 10:45am HST
Vegetable transplant producers supply approximately $250 million worth of transplants to vegetable growers throughout the United States. Proper nutrient application for transplant production is important for crop establishment and minimizing excessive fertilizer waste which can negatively affect surface and groundwater. However, nutrient application guidelines for vegetable transplants grown in soilless substrate are limited. Therefore, researchers undertook a study to determine optimal nitrogen (N) concentrations for the top five transplanted vegetable crops produced in California. Greenhouse trials were conducted on leaf lettuce, romaine lettuce, processing tomato, broccoli, and celery transplants. Three treatments were applied in each trial (One 200-cell plug tray per treatment, replicated five times each): (1) 400 ppm N; (2) 200 ppm N; (3) 50 ppm N. Fertigation was applied to trays placed on weighing-lysimeters and total daily transpiration was recorded. Once transplants were fully developed, they were harvested and analyzed for shoot fresh weight and shoot dry weight. Fresh plant tissue was sent to an agricultural laboratory for nutrient content testing. Total nutrient uptake (mg) was calculated by multiplying nutrient tissue content (%) by shoot dry weight (mg). N fertilizer concentration (mg*L-1) was calculated by dividing the total N uptake value (mg) by transpiration (L). Transplants in the 400 ppm treatment had significantly higher N tissue content, compared to the 200 and 50 ppm treatments, in all crop trials except for leaf lettuce. In the leaf lettuce trial, the 400 and 200 ppm treatments had similar N tissue content. Average shoot dry weight was similar between the 200 and 400 ppm N treatments in all five crops, indicating that both treatments provided sufficient N. Based off these results, we recommend applying 246 ppm N to leaf lettuce, 232 ppm N to romaine lettuce, 304 ppm N to processing tomato, 437 ppm N to broccoli, and 262 ppm N to celery transplants. These values are based off the calculated N fertilizer concentrations which produced the highest shoot dry weights.
Speakers
EV

Emma Volk

UC Cooperative Extension
Co-authors
BP

Bruno Pitton

University of California Cooperative Extension
NA
LO

Lorence Oki

University of California, Davis
NA
Friday September 27, 2024 10:30am - 10:45am HST
South Pacific 2

10:30am HST

VSF 5 - Prohexadione Calcium is an Effective, Dose Dependent Growth Retardant of ‘Osage’ Blackberry
Friday September 27, 2024 10:30am - 10:45am HST
Blackberry primocane growth management in the Southeastern US relies on tipping to manage vegetative growth. Tipping can increase lateral branching, bearing surface, and subsequent yield. However, the practice is labor intensive and expensive (~$600/acre). Furthermore, tipping wounds are sites for cane blight infection (Leptosphaeria coniothyrium) resulting in cane dieback, decline and death. Alternative strategies to tipping could reduce labor and fungicide inputs in a given season. Prohexadione calcium (P-Ca) is commonly used to control terminal shoot growth in other Rosaceous crops. We evaluated the relationship between P-Ca rate on blackberry vegetative and reproductive development. The experiment was conducted on a mature planting of ‘Osage’ floricane-fruiting blackberry at Clemson University’s Musser Fruit Research Center in Seneca, SC. The experiment had a completely randomized design with four replications. Treatments consisted of an untreated control and P-Ca applied at 62.5, 125, 250, and 500 ppm with a 0.125% (v:v) non-ionic surfactant and 0.39% (v:v) water conditioner. P-Ca treatments were applied 6 times at ~21 day intervals to the same plots across two consecutive years, 2019 and 2020. Regression analysis was conducted to determine the relationships between P-Ca and measured parameters. There was a consistent, negative relationship between P-Ca rate and primocane height across two years, which was linear in 2019 and curvilinear in 2020. A negative curvilinear relationship between P-Ca rate and yield was observed in 2020 beginning 8 weeks after P-Ca treatments were initiated until the final harvest. There were no consistent effects of P-Ca on fruit weight. P-Ca reduced total lateral length, number of lateral branches, and final cane length by 60 - 65% at the 250 ppm and 500 ppm rates. P-Ca is an effective growth retardant of blackberry, but the negative relationship between P-Ca rate and yield merits additional research. Future research should focus on post-harvest applications of P-Ca to minimize dormant pruning costs and applications in controlled environments.
Speakers Co-authors
JC

Juan Carlos Melgar

Clemson University
NA
TM

Thomas M. Kon

North Carolina State University
NA
Friday September 27, 2024 10:30am - 10:45am HST
Coral 3

10:30am HST

WCPM 4 - Directed Energy System: A Non-chemical Approach for the Management of Nematodes, Pathogens, and Weeds in Nurseries
Friday September 27, 2024 10:30am - 10:45am HST
Oregon leads the United States in the production of several ornamental nursery products including shade trees, conifers, and flowering trees. Soilborne pathogens and weeds are major constraints to the production of tree seedlings for the ornamental industry. Failure to control pathogens can result in seedling death or unintentional distribution of infected nursery stock while failure to control weeds can lead to competition with seedlings for water and nutrients. One of the primary ways to control soilborne pathogens and weeds is through pre-plant fumigation with methyl bromide. The use of this chemical is detrimental to the environment and human health, making it urgent to develop safer alternatives. Our long-term goal is to discover new ways to manage nematodes, soilborne pathogens, and weeds that will reduce reliance on pesticides and soil fumigants and be safer for the environment. Directed Energy System (DES) has been developed as a novel application technique, which generates pulses of electricity capable of killing nematodes, pathogens, and weeds. Controlled experiments were conducted against Meloidogyne chitwoodi, Phytophthora cinnamomi, and Cyperus esculentus to determine the electrical parameters required to kill each organism. Preliminary data demonstrated that the energy required to kill 90% of M. chitwoodi eggs was 23.4 J/cm3 of soil and for C. esculentus nutlets the energy for reduce weed growth by 50% ranged from 55 to 116 J/cm3 of soil.
Speakers
avatar for Tatiana Benedetti

Tatiana Benedetti

Oregon State University
Co-authors
JC

Jason Crisp

Lisi Global
NA
MM

Marcelo Moretti

Oregon State University
Friday September 27, 2024 10:30am - 10:45am HST
South Pacific 4

10:45am HST

CE 7 - The Nitrate to Ammonium Ratio Impacts Strawberry Runnering and Daughter Plant Number
Friday September 27, 2024 10:45am - 11:00am HST
The use of controlled environments to produce disease-free vegetative clones of strawberry (Fragaria ×ananassa) is increasing. However, protocols for mother plant management that optimize runner and daughter plant number need to be developed. Studies have shown that decreasing the fraction of nitrogen (N) supplied as nitrate (NO3-) can encourage vegetative growth in other crops. Our objective was to identify the %NO3--N that maximized runner and daughter plant number. Strawberry ‘Albion’, ‘Fronteras’, and ‘Monterey’ were grown in 19.1-cm pots filled with a peat-based substrate. Plants were irrigated with a modified strawberry nutrient solution (Yamazaki) that provided a total of 100 mg·L-1 N. The percent of total N supplied as NO3- ranged from 0% to 100%, with the remainder supplied as ammonium (NH4 ). Runners and daughter plants were harvested after eight and 16 weeks of treatment. The impact of %NO3- on cumulative runner number was cultivar specific. ‘Albion’ was not impacted, and the overall mean was 9 ± 1 (± SE).‘Fronteras’ exhibited a quadratic response. It increased from 10 ± 2 at 0% NO3- to 17 ± 2 at 60% NO3-; the calculated maximum runner number was with 64% NO3-. ‘Monterey’ exhibited a linear increase, from 14 ± 1 at 0% NO3- to 22 ± 1 at 100% NO3-. The impact of %NO3- on cumulative daughter plant number was also cultivar specific. ‘Abion’ exhibited a linear increase, from 28 ± 2 at 0% NO3- to 37 ± 10 at 100% NO3- . ‘Fronteras’ exhibited a quadratic response and increased from 19 ± 2 at 0% NO3- to 45 ± 7 at 60% NO3-. ‘Monterey’ also exhibited a quadratic response and increased from 49 ± 4 at 0% NO3- to 90 ± 7 at 80% NO3-. Calculated maximum daughter plant number occurred at 66% and 81% NO3- in ‘Fronteras’ and ‘Monterey’, respectively. Overall, at least 60% NO3- provided robust runner and daughter plant number, but the response depended on cultivar evaluated. ‘Monterey’ and ‘Albion’ appear to prefer a higher %NO3- than ‘Fronteras’ for maximum runner and daughter plant number.
Speakers
EY

Erin Yafuso

United States Department of Agriculture
Co-authors
JB

Jennifer Boldt

United States Department of Agriculture
Friday September 27, 2024 10:45am - 11:00am HST
Nautilus

10:45am HST

CHMG 2 - Utilizing Facebook and Instagram to Distribute a Residential Horticultural Needs Assessment
Friday September 27, 2024 10:45am - 11:00am HST
Homeowners and gardeners source their landscape education from various media outlets and social media platforms. Leveraging the substantial following of the UF/IFAS Master Gardener social media page, which boasts over 40,000 followers, presents a unique opportunity to discern the horticultural education needs of homeowners and their preferred dissemination methods. In 2023, a Qualtrics horticultural needs assessment survey was developed and distributed via Facebook and Instagram to followers. Prior to survey distribution, an Institutional Review Board was completed and approved under the non-human/exempt auto-determination tool. The Qualtrics needs assessment comprised twelve questions covering topics such as horticultural interests, availability, and preferred learning platforms. Four visually engaging posts were shared, two each in December 2023 and January 2024. Of these posts, 309 respondents agreed to participate in the study. Our findings aligned with current gardening trends, with homeowners expressing a need for information on native plants, pollinators, vegetable gardening, and invasives. Among respondents, 21% favored online classes over 15% for in-person classes. Additionally, digital documents were preferred by 18% of respondents compared to 14% for print documents. Notably, 20% of respondents expressed a preference for short online videos for receiving horticultural information. Survey participants were also queried on their preferred time of year for attending classes, both in person and online, with no clear preference observed. Regarding in-person classes at local extension offices, 54% indicated willingness to attend, while 11% were unaware of their local extension office's location. When asked about their interactions with Master Gardener Volunteers, 31% reported satisfaction, 12% dissatisfaction, and 48% had not interacted with a Florida Master Gardener Volunteer. Interestingly, 62% of respondents expressed a preference for garden-related content on YouTube. While the response rate was relatively low, it suggests that direct email or in-person approaches might have yielded more productive results. Nonetheless, the findings are compelling, indicating a promising direction for extension programming in the digital age. They underscore the potential benefits of transitioning towards short-form video content and utilizing platforms like YouTube to effectively meet homeowners' horticultural education needs. Overall, the study illuminates the evolving landscape of horticultural education and underscores the importance of adapting dissemination strategies to better engage homeowners in the digital realm.
Speakers
CJ

Claude Judith Jean

University of Florida
Friday September 27, 2024 10:45am - 11:00am HST
South Pacific 1

10:45am HST

FLOR 3 - Moisture Content Effects Microbial Activity in Substrates Derived from Five Different Hammermilled Wood Species Over the Course of Greenhouse Petunia Production
Friday September 27, 2024 10:45am - 11:00am HST
Recently, the limited availability of Sphagnum peat moss due to poor weather conditions impacting harvests, and additional scrutiny from media and public outlooks has brought up serious questions about the long-term security of peat use in the horticulture industry. The search for alternative amendments began decades ago, with several products being evaluated over the years. Many have been found suitable for niche production settings, with few seeming to fit the industry somewhat ubiquitously. Of these, wood fiber is seemingly the most promising as it is a renewable resource that is available globally. Wood fiber amendments have been trialed extensively with industry emerging and scaling internationally. Wood can be processed to support many different applications in horticulture, giving it more robust qualities than other top components. There are some disadvantages to wood usage, namely, nitrogen immobilization. Wood contains large amounts of easily degradable carbon. Therefore, microorganisms will consume this carbon for energy by utilizing plant available nitrogen causing plant nutrient deficiencies. Microbial community activity is heavily influenced by moisture. Considering this, a study was developed to observe how the microbial activity of different hammermilled wood tree species may be influenced by moisture content in a greenhouse crop production cycle. Five tree species (Abies concolor, Calocedrus decurrens, Pinus lambertiana, Pinus ponderosa, and Pseudotsuga menziesii) were harvested in California and hammermilled. The wood particles were blended with a commercial peat-based substrate at 30% (by vol.). Supertunia ‘Honey’ plugs were planted in each of the substrate blends and grown on a greenhouse bench for 75 days. The crops were held at 25% and 35% volumetric water content using cantilever-style lysimeters and fertigated with water-soluble fertilizer, weekly. Crop growth and performance was assessed throughout production. Substrate CO2 was assessed pre- and post- production to assess microbial activity. The results will help assess the potential of utilizing differing tree species for wood fiber, and understand any adjustments that will be necessary to production practices.
Speakers
AM

Amanda Mizell

Louisiana State University AgCenter
Co-authors
BJ

Brian Jackson

North Carolina State University
NA
DA

Damon Abdi

Louisiana State University Agricultural Center
JF

Jeb Fields

LSU AgCenter Hammond Research Station
Friday September 27, 2024 10:45am - 11:00am HST
Kahili

10:45am HST

GG 3 - Alaska Can Grow More Than Giant Vegetables: The Potential of Rhubarb for Specialty Crop Producers
Friday September 27, 2024 10:45am - 11:00am HST
Specialty crop producers in Alaska need consistent, suitable crop and varietal options for successful commercial production, as food security is a major concern in this state that imports 95% of its food. The climate in much of Alaska is ideal for cool season, perennial corps that are winter hardy, such as Rhubarb (Rheum sp.). Rhubarb was brought to Alaska through several waves of immigration from regions extending from Russia through England and is now established throughout the state. Once a site for the National Plant Germplasm System (NPGS) Arctic and Subarctic Plant Gene Bank, the University of Alaska Fairbanks Matanuska Experiment Farm and Extension Center still maintains a collection of 41 accessions of Rheum sp. in the field. In addition, a new collection of heirloom rhubarb plants has been assembled by a local grower and maintained in large pots. In this project, we collected leaf samples from the heirloom collection plants for genotyping and phenotyping, as well as benchmark samples from plants remaining in the former germplasm collection, to provide an understanding of relatedness and desirable characteristics. A 5 cm square sample of leaf tissue was harvest from each plant, dried, and sent to a commercial laboratory for genotyping. Size and color of leaves and petioles, dates of emergence, plant vigor, and juice quality were measured on plants from the heirloom collection. Finally, surveys carried out of the last 12 years targeted a diversity of stakeholders (commercial producers, business owners, and the general public) to identify rhubarb quality expectations, including flavor, juice content, petiole color, and plant vigor. Based on genotyping results, plants not genetically redundant to those in the NPGS rhubarb collection currently located in Pullman, Washington, will be added to the collection. We present recommendations for variety suitability for different climate regions of Alaska based on the traits measured, taking into account varieties of rhubarb currently available wholesale to Alaska. Recommendations are also presented for further research into commercial production and added-value characteristics.
Speakers
CM

Carol Miles

Washington State University
Co-authors
AC

Alex Cornwall

USDA ARS
NA
AK

Ann Kowenstrot

University of Alaska Fairbanks
Friday September 27, 2024 10:45am - 11:00am HST
Coral 1

10:45am HST

ORGH 3 - Cover Crops Potential for Regulating Soil Moisture and Temperature in Drive-row of an Irrigated Organic Vineyard
Friday September 27, 2024 10:45am - 11:00am HST
The utilization of cover crops in vineyards has been promoted for their role in moderating soil climate, thus enhancing vineyard resilience to extreme weather conditions. This study evaluated the effectiveness of three drive-row cover crop treatments in regulating soil moisture and temperature within an irrigated organic vineyard characterized by loamy sand soil, located in the semiarid Okanagan Valley, Canada, over the period from 2021 to 2023. Selection of cover crop species was informed by prior greenhouse and field screening experiments. The implemented treatments, established in May 2021, included a mixture of perennial ryegrass, tillage radish, and white clover (PRTRWC); a fescue mixture with white clover (FWC); cereal rye with hairy vetch (CRHV); and a Control (existing vegetation/weeds). The vineyard was equipped with drip lines and undercanopy sprinklers. Soil moisture and temperature were monitored every four hours using Teros 11 sensors at a 10 cm depth in the drive-row. Seasonal observations revealed the highest soil volumetric water content (Ɵv) from November to April, aligning with cooler temperatures and increased precipitation. The Ɵv ranged from 0.10 to 0.14 and significant differences in average Ɵv were noted among the all treatments over the three growing seasons (May to Oct), with CRHV displaying the highest levels, followed by FWC, Control, and PRTRWC. Notably, substantial differences in Ɵv (
Speakers
avatar for Mehdi Sharifi

Mehdi Sharifi

Research Scientist, Summerland Research and Development Centre
Dr. Mehdi Sharifi is a “soil nutrient management” research scientist at Summerland Research and Development Centre in British Columbia, Canada. Before his current position, he was a professors at Trent and Dalhousie Universities. He completed two postdoctoral fellow positions... Read More →
Co-authors
JY

Jamie Yearley

University of British Columbia Okanagan Campus
NA
MJ

Melanie Jones

University of British Columbia Okanagan Campus
NA
ZZ

Zahra Zolfaghari

University of British Columbia Okanagan Campus
NA
Friday September 27, 2024 10:45am - 11:00am HST
South Pacific 3

10:45am HST

VCM 6 - Growing Resilient Broccolini: Harnessing Clover Living Mulch for Weed Suppression and Yield Enhancement
Friday September 27, 2024 10:45am - 11:00am HST
Growing broccoli to a marketable standard can be difficult in a changing climate with more extreme heat events during the growing season. The use of more heat tolerant Brassica species in combination with living mulch could address both issues. A study in Brookings, SD investigated established clover living mulch and in-row soil management impacts on the performance of four of broccolini (Brassica oleracea) cultivars – ‘Melody,’ ‘BC1611,’ ‘Burgundy,’ and ‘Bonarda.’ Three established clover varieties (‘Domino’ white clover (Trifolium repens), ‘Aberlasting’ white x kura clover (T. repens x ambiguum), and ‘Dynamite’ red clover (Trifolium pratense)) and a bare-ground control were used in combination with four in-row soil management strategies (till, no-till, till fabric, and no-till fabric). These 16 combinations were evaluated for their impact on weed suppression, broccolini crop growth and yield. It was observed that annual weeds such as yellow foxtail (Setaria pumila) and Venice mallow (Hibiscus trionum) were present in bare ground plots and were reduced in all clover plots. Some perennial weeds such as dandelion (Taraxacum spp.) and perennial sow thistle (Sonchus arvensis) were able to compete with clover. Sufficient clover biomass was accumulated for weed suppression. Weed biomass was reduced by 80% in white and red clover plots, and 95% in the white x kura clover plots compared to the control. Broccolini yield was reduced within all three clover no-till treatments. Broccolini grown in other clover soil management combination had similar yields indicating greater resistance to yield decreases commonly observed in living mulch research. Other data collected in this study included clover nodule counts and broccolini crop health metrics – height, canopy width, and SPAD. Results from the first year of research demonstrate that perennial clover living mulch can be used in the Great Plains to suppress weeds between planting rows. However, the use of landscape fabric within the planting row is necessary to prevent a reduction in broccolini yield. Planting broccolini into a living mulch system shows potential for vegetable producers to reduce inputs and labor on their farms while maintaining crop yield.
Speakers
CR

Connor Ruen

South Dakota State University
NA
Co-authors
KL

Kristine Lang

South Dakota State University
TN

Thandiwe Nleya

South Dakota State University
NA
Friday September 27, 2024 10:45am - 11:00am HST
South Pacific 2

10:45am HST

VSF 5 - Impacts of the ‘Fan’ Training Method on Blackberry Yield and Fruit Quality on the Rotating Cross-Arm Trellis
Friday September 27, 2024 10:45am - 11:00am HST
Based on six years of research at the University of Arkansas, the rotating cross-arm (RCA) trellis has been shown to improve several aspects of blackberry production such as yield and fruit quality. Through this research, a new training method coined the ‘fan’ method was developed with the potential to maximize canopy fill and decrease labor. A trial was conducted from 2022 to 2024 at the University of Arkansas Fruit Research Station (UAFRS) in Clarksville, AR to verify the ‘fan’ method and test new cultivars not used in previous trials. The blackberry cultivars ‘Ponca’, ‘Von’ and ‘Caddo’ were planted in 2021 on a 33m row of t-trellis and a 33m row of RCA trellis in a randomized complete block arrangement. The plants were spaced 0.76 m apart in four plant plots replicated three times per trellis treatment. The ‘fan’ training method (primocanes tipped at 30 cm and laterals trained upward and fanned out on the long arm) was implemented on the RCA trellis treatment for all plants. The t-trellis was tipped at the top wire following practices standard for the region. Blackberry yield, fruit quality, and physiological data were collected during 2023 and 2024. Preliminary results from 2023 showed the ‘fan’ method on the RCA can achieve similar yields to the T-trellis but offer the opportunity to protect the crop from severe cold events and reduce the incidence of fruit quality disorders for some cultivars. All the varieties evaluated were found to be suitable for use on the RCA with the fan method however differences in cane vigor were noted and cultivar can be the biggest determinant of yield and fruit quality regardless of trellis type.
Speakers
avatar for Lizzy Herrera

Lizzy Herrera

University of Arkansas System Division of Agriculture
Co-authors
AL

Amanda Lay Walters

University of Arkansas System Division of Agriculture
NA
AM

Amanda McWhirt

University of Arkansas System Division of Agriculture
KB

Keilah Barney

University of Arkansas System Division of Agriculture
NA
MD

Mataya Duncan

University of Arkansas System Division of Agriculture
NA
RT

Renee Threlfall

University of Arkansas System Division of Agriculture
NA
Friday September 27, 2024 10:45am - 11:00am HST
Coral 3

10:45am HST

WCPM 4 - Sweetpotato-associated Virome in Mississippi
Friday September 27, 2024 10:45am - 11:00am HST
Sweetpotato (Ipomoea batatas; Convolvulaceae) is an economically important specialty crop with an overall U.S. production valued at more than $720 million (2020 data, USDA-NASS). Even though virus infections are a major constraint to the sweetpotato industry across the United States and around the globe, organized studies have not been conducted to understand virus diversity and incidence. Therefore, an objective of a transdisciplinary multistate, Specialty Crop Research Initiative (SCRI), CleanSEED Project is to characterize viruses associated with sweetpotato production in major producing states. To that aim, 25 different locations/production fields in Mississippi were surveyed during the 2023 production season to collect symptomatic foliar tissue for total RNA extraction. The detection and identification of viruses of sweetpotatoes was based on a high-throughput sequencing approach on an Illumina platform utilizing 2x150 nt pair-end methodology, followed by computational analyses of billions of raw sequence reads. The four potyviruses, considered of major economic importance for the crop, were prevalent in the state and frequently occurred in mix infections. Furthermore, a few other viruses with possible hosts different than plant, were associated with plants analyzed in this study. This research was supported by the intramural research program of the U.S. Department of Agriculture, National Institute of Food and Agriculture, Specialty Crop Research Initiative, accession no. 1029242.
Speakers
SS

Sead Sabanadzovic

Mississippi State University
Co-authors
LH

Lorin Harvey

Mississippi State University
NA
MS

Mark Shankle

Mississippi State University
NA
NA

Nina Aboughanem

Mississippi State University
NA
Friday September 27, 2024 10:45am - 11:00am HST
South Pacific 4

11:00am HST

CE 7 - Effect of Monosilicic Acid on Growth and Physiology of Lettuce
Friday September 27, 2024 11:00am - 11:15am HST
Due to the high operation costs of indoor crop production, improving resource use efficiency to reduce costs has gained importance for sustainability in recent years. Silicon (Si) is not an essential plant nutrient since it is not a component of any structural or metabolic molecule, and plants do not suffer from Si deficiency. However, Si applications have shown beneficial effects on various crops, including improved growth, quality, stress tolerance, and water use efficiency (WUE). This study evaluated the effects of Si on indoor lettuce production to enhance lettuce growth and WUE. Two-week-old lettuce seedlings (Lactuca sativa cv. ‘Green Forest’ and ‘Rouxai’) were transplanted into 5-L deep water culture systems and grown for four weeks in a custom growth chamber with an average temperature/relative humidity of 22.4°C/58.8% and light intensity of 230 µmol/m²/s PPFD. The nutrient solution was weighed and replenished weekly. Si (DUNE™ stabilized monosilicic acid) was applied weekly to plants following two application methods (RA=root application and FS=foliar spray) and three concentrations (Control=0 ppm, C1=264 ppm, and C2=528 ppm). RA C1 significantly improved the shoot fresh weights (FW) and dry weights (DW) of both lettuce cultivars, while FS C1 was less effective than RA. Root growth showed the opposite trend, with FS C1 having the highest root FW and DW of both cultivars. However, root morphology showed cultivar-specific responses, with RA C1 producing the highest root length and surface area in ‘Green Forest’ and FS C1 the highest root surface area and volume in ‘Rouxai.’ WUE was significantly improved by RA C1, RA C2, and FS C2 in ‘Green Forest’ and RA C1 in ‘Rouxai’ compared to the control. Taken together, root application of Si at C1-264 ppm concentration most effectively improved the indoor lettuce growth and WUE.
Speakers
SC

Seunghyun Choi

Postdoctoral research associate, Texas A&M Agrilife Research
Co-authors
JH

Joshua Harvey

Texas A
NA
VJ

Vijay Joshi

Texas A
NA
Friday September 27, 2024 11:00am - 11:15am HST
Nautilus

11:00am HST

CHMG 2 - Exploring the Ethical Viewpoints of Proplifiting Among Consumers
Friday September 27, 2024 11:00am - 11:15am HST
In recent years, the trend of owning and propagating houseplants has steadily grown. Consumers find this hobby to be relaxing and find it rewarding when their cuttings successfully grow roots and new leaves. Because of the ease that propagation gives us to clone plants, many people are exploring methods to acquire more plants for free. One common method is through proplifting. Proplifting is the habit of stealing plant material for the practice of creating new plants; this is done through collecting discarded material (leaves, nodes, roots, seed), or by stealing parts of a plant that are still attached. While proplifting appears harmless, it is important to consider all factors, such as how it might affect the business, non-profit, or individual that one is taking this plant material from. Additionally, taking protected plant material – such as from plants that are being grown from conservation efforts – could drastically harm the preservation of a species. This national survey looks at how consumers view the ethics around proplifting and the degree to which they would consider a situation to be ethically acceptable or unacceptable.
Speakers
LG

Leandria Garrett

University of Georgia
Co-authors
avatar for Julie Campbell

Julie Campbell

University of Georgia
Friday September 27, 2024 11:00am - 11:15am HST
South Pacific 1

11:00am HST

FLOR 3 - Stratification significantly reduces the phytotoxic effects of fresh hardwood
Friday September 27, 2024 11:00am - 11:15am HST
With a global increased demand for growing substrates and specifically wood alternative substrates, methods are being tested to better understand wood as a product and how to incorporate wood into growing medium substrates. This study investigated the use of fresh whole-tree loblolly pine and whole-tree hardwood in horticultural greenhouse settings, focusing on how varying wood blend compositions and levels of stratification affect plant growth. Analysis revealed that increasing hardwood percentage in blends led to decreased plant growth, while stratification reduced differences among blends. Notably, at lower stratification levels, plant growth resembled that of the control treatment. Statistical tests confirmed these trends, highlighting the significant impact of wood blend composition on plant dry weight. Findings suggest that while hardwood incorporation decreases growth, stratification can mitigate differences among blends, allowing for the incorporation of untreated wood material. These results offer insights for optimizing wood blend usage in greenhouse cultivation, providing sustainable solutions for horticultural practices. Key Words: Hardwood, Stratification, Phytotoxicity, Wood Blends, Plant Growth.
Speakers
AT

Andre Truter

North Carolina State University
Friday September 27, 2024 11:00am - 11:15am HST
Kahili

11:00am HST

GG 3 - Utilization of Germplasm to Improve Illinois Horseradish
Friday September 27, 2024 11:00am - 11:15am HST
Horseradish (Armoracia rusticana, Brassicaceae) is an important specialty crop in Illinois, with most commercial production adjacent to St. Louis, Missouri in what is known as the Mississippi Bottoms. The continued development of new, improved horseradish cultivars is critical to sustain this important specialty crop industry, since horseradish clonal cultivars tend to "run out" and lose their productivity over a period of about 10 years. A small germplasm collection of clones from eastern Europe and Russia, as well as old cultivars no longer in wide use and other breeding materials that were saved from the breeding program has been maintained since the 1960s, first at University of Illinois until the early 2000s and now at Southern Illinois University-Carbondale. During the last 20 years, germplasm has been utilized from various sources to improve horseradish so this industry can sustain itself for the near future. The following examples are provided to illustrate the importance of new germplasm in new horseradish cultivar development. Accession 761A collected from Drążgów, Poland was instrumental in developing horseradish cultivars with tolerance to internal root discoloration which is caused by a soil-borne pathogen complex. The germplasm clone Czech has been very effective in transmitting its large root size trait to its resulting progeny and was used in many crosses made from 2005 to 2010. Many cultivars grown today have this germplasm source in their background. Another important clonal cultivar known as 9705 was widely grown during the 2000s and resulted from outcrossing accession 758A collected from Ribnica, Slovenia with an unknown male. Additionally, 315 is another very important cultivar that was the workhorse for the industry from 2005 to 2015 having lineage also from 758A. 15K was another industry workhorse in the late 1990s to early 2000s, and had its primary lineage traceable to 856A, an accession from the Czech Republic. These are a few examples of how germplasm sources have contributed to sustaining the Illinois horseradish industry and each will be discussed in further detail regarding their specific benefits. Moreover, most are still used in some capacity in the breeding program today.
Speakers
AW

Alan Walters

Southern Illinois University
Friday September 27, 2024 11:00am - 11:15am HST
Coral 1

11:00am HST

ORGH 3 - Apple Rootstocks Affect Soil Rhizosphere Microbial Communities and Root Exudate Composition
Friday September 27, 2024 11:00am - 11:15am HST
The plant rhizosphere plays a key role in plant function and immunity. Apple Replant Disease (ARD) is a dysbiosis in apple rhizosphere environments that have a history of apple cultivation. Due to increased intensification of apple growing systems and land scarcity, ARD incidence is on the rise and can result in a 50% loss of profitability to growers. Soil fumigation is a common practice for mitigating ARD, but has limited efficacy and is not allowed in some areas because of potential for environmental damage and human harm. Using resistant rootstocks is a key strategy in overcoming ARD. To understand rootstock resistance, it is important to describe and characterize the microbial communities of various rootstocks in an environment conducive to microbial health. We planted an organically managed apple orchard with 5 randomized repetitions of 15 different rootstocks. In both 2022 and 2023, we sampled the soil adhering to the roots of these trees for DNA extraction in order to characterize both bacterial and fungal microorganisms in the rhizosphere of the rootstocks in our research. We also established an aeroponic greenhouse trial (randomized with three repetitions) to sample rhizodeposits from 6 of the rootstocks used in the orchard trial, with the aim of characterizing metabolites with untargeted HPLC/LCMS. Bacterial phyla and genera differed in relative abundance between the rootstocks. A sparse PLS (partial least squares) discriminant analysis of rootstock exudates revealed differential sorting of some rootstocks. Neither study revealed clear biological indicators for ARD resistance, but the results evince that rootstock genotype does influence both microbial community and tree root exudation patterns.
Speakers
JC

Julie Cardon

Cornell University
Co-authors
GF

Gennaro Fazio

Cornell University /USDA
NA
GP

Greg Peck

Cornell University
NA
JT

Janice Thies

Cornell University
NA
TR

Terence Robinson

Cornell University
NA
Friday September 27, 2024 11:00am - 11:15am HST
South Pacific 3

11:00am HST

VCM 6 - Foliage Removal on Processing Sweet Corn Reduces Yield Most Strongly Near Tasseling
Friday September 27, 2024 11:00am - 11:15am HST
Sweet corn is an important processing crop in the upper Midwestern United States. It can be insured for hail losses, but actuarial tables are based on field corn. The first step in developing accurate yield loss estimates is to determine yield loss due to stand loss. The second step is to determine yield loss due to defoliation. To understand the impacts of defoliation on sweet corn yield, we compared ear yield with estimated 25, 50, 75, or 100% of leaf area removed at five times throughout the growing season to control plots that were not defoliated. Defoliation was carried out with a Christmas tree shearing knife or machete. We repeated this in three consecutive years at two locations, without irrigation or supplemental fertilizer. Yield was measured as both green ear mass and cut kernel mass. Measured loss due to defoliation was generally less than actuarial estimates, except shortly before tasseling or at 25% defoliation. A regression equation predicting yield relative to control based on a) growing degree days before damage and b) percent defoliation were developed, combining all site-years. We measured little yield loss with 25 or 50% defoliation or 75% defoliation near V8, and we measured greatest yield loss near tasseling with 100% leaf removal. Kernel and ear mass were strongly correlated. These results illustrate resilience of sweet corn to foliage loss and potential need for adjustment of actuarial tables for hail loss.
Speakers
avatar for Charlie Rohwer

Charlie Rohwer

Scientist, University of Minnesota
Co-authors
JL

Joe Lauer

University of Wisconsin-Madison
NA
MZ

Mark Zarnstorff

National Crop Insurance Services
NA
Friday September 27, 2024 11:00am - 11:15am HST
South Pacific 2

11:00am HST

VSF 5 - Evaluation of a Strawberry (Fragaria × ananassa) Cultivar Trial for Yield and Fruit Quality in Lubbock, Texas
Friday September 27, 2024 11:00am - 11:15am HST
Due to its sweet and aromatic flavor, nutritional value, and health-associated beneficial compounds, strawberry (Fragaria x ananassa) is worldwide cultivated fruit crop. Texas strawberry cultivation is gaining popularity because strawberry production may give considerable economic returns in a relative short period of time. However, profitable strawberry cultivation is intricately tied to selection of suitable cultivars for prevailing environmental conditions. To identify the most appropriate cultivars for a specific region, it is critical to thoroughly evaluate strawberry cultivar growth, yield potential, and various quality characteristics within each diverse agro-climatic location. Hence, to evaluate strawberry cultivars for superior yield and fruit quality characteristics and determine suitable cultivars for cultivation in the region, this study was conducted at the TAMU AgriLife Research and Extension Center in Lubbock, TX. Twenty cultivars (8 day neutral and 12 June bearing) were established Fall of 2022 as bare root plants and data collection began Spring of 2023. Each cultivar was assessed for morphological, physiological, and agronomic traits. Trial results reveal significant variation in performance of evaluated cultivars. Yield and berry number were greatest for ‘Rikas’, ‘Cabrillo’, ‘Brilliance’, ‘Fronteras’, and ‘Beauty’, whereas ‘Keepsake’ was the lowest yielding cultivar and produced the fewest number of fruits. Berry size was greatest for ‘Monterey’, ‘Sweet Ann’, ‘Royal Royce’, ‘Cabrillo’, ‘Valiant’ and ‘San Andreas’, whereas ‘Keepsake’ had the smallest berries. Leaf gas exchange measurements revealed photosynthetic rate and conductance was least for ‘Sierra’. Fruit quality (total soluble solids, °Brix) was greatest for ‘Keepsake’ (11.9°) and lowest for ‘Radiance’ (7.6°). ‘Keepsake’ and ‘Victor’ fruit appeared to be resistant to Botrytis, whereas ‘Festival’ and ‘San Andreas’ were more susceptible. ‘Victor’ plants had the greatest percentage canopy green cover, whereas ‘Medallion’ had the least green canopy cover. Yield and fruit quality data indicate top day-neutral cultivar were ‘Cabrillo’, ‘Rikas’, and ‘Beauty’, while top June-bearing cultivars were ‘Brilliance’ and ‘Fronteras’. Preliminary research suggests cultivars ‘Rikas’, ‘Cabrillo’, ‘Brilliance’, ‘Fronteras’, and ‘Beauty’ may be adapted to the Lubbock area and do well for commercial strawberry cultivation. However, results are based upon data from a single growing season, and further research and analysis of data will confirm results.
Speakers
SP

Srijana Panta

Graduate Research Assistant, Texas Tech University
Co-authors
RW

Russ Wallace

TAMU AgriLife Extension
NA
TM

Thayne Montague

Texas Tech University
Friday September 27, 2024 11:00am - 11:15am HST
Coral 3

11:00am HST

WCPM 4 - Evaluation of Insecticide Application Plan to Manage Thrips for Sweet Onions in Texas
Friday September 27, 2024 11:00am - 11:15am HST
Thrips is an important pest of onions that not only reduces yield and quality but also transmit Iris Yellow Spot Virus. The study’s objective was to evaluate different chemical application plans to manage the thrips population in onions. The study was conducted in a split plot design with variety as a main plot and chemical plan as a sub-plot with four replications at Texas A&M AgriLife Research and Extension Center, Uvalde, TX during the 2022-23 season. The variety factor had three levels – Hornet, Mata Hari, and Don Victor. The chemical plan factor also had three levels – weekly application, action threshold (1 thrips per leaf), and control. Although the insect population was low, in general, for the season, the weekly application and action threshold treatments had a lower number of thrips per leaf than the control treatment. The numbers of chemical applications for the weekly application and action threshold were six and three, respectively. The results indicate that growers would save input costs if followed by the action threshold chemical plan. The trial will be evaluated in the 2023-24 season to validate results from the first season.
Speakers
SM

Subas Malla

Associate Professor, Texas A&M AgriLife Research
Friday September 27, 2024 11:00am - 11:15am HST
South Pacific 4

11:15am HST

CE 7 - Light Intensity and Zinc Biofortification Effect on Yield and Nutritional Quality of Pea and Radish Microgreens
Friday September 27, 2024 11:15am - 11:30am HST
Zinc (Zn) is a micronutrient crucial for human health, impacting gene expression, cell division, and immune system development. Zinc deficiency affects about 17% of the global population, particularly children, pregnant women, and elderly people, and can lead to disorders and even death. Agronomic biofortification implemented by applying Zn-enriched solutions via fertigation to increase crops Zn content may be a valuable strategy to combat Zn deficiencies. Microgreens, known for their nutrient density, rapid growth cycle, and low phytic acid content, are emerging as promising candidates for Zn agronomic biofortification. However, research is needed to evaluate the effect of factors like light intensity and genotype which can affect Zn accumulation in microgreens. To this purpose, a study was conducted to examine the effect of Zn application rate (0, 5, 10, and 15 mg/L) and light intensity (100, 200, 300, and 400 µmol/m2/s) on yield components, mineral content, and phytochemical profile of pea and radish microgreens. The study revealed that Zn concentration increased with increasing concentration of Zn applied in both species. In peas, a 4-fold increase was observed when applying 15 mg/L of Zn without affecting fresh and dry biomass, while an almost 13-fold increase of Zn content was observed in radish, associated with a 7.8% reduction of fresh biomass and no effects on radish microgreens dry biomass. However, with the increase of Zn content, there was a reduction in Fe concentration in both peas and radish microgreens. The light intensity did not affect Zn content in both species; however, it affected the concentration of macro and other microelements and influenced yield, but the result varied by species. In pea microgreens, low light intensity determined higher fresh biomass but did not affect dry biomass. Instead, the opposite result was observed in radish microgreens; light intensity did not affect fresh yield but increased dry biomass with increasing the level of light intensity applied. Regarding the nutritional profile, total phenols, total antioxidants, and flavonoids increased with increasing Zn concentration and light intensity in both pea and radish microgreens. In conclusion, Zn fertigation effectively enhanced Zn in pea and radish microgreens, and although light intensity had no effect on Zn content, contributed to improve their nutritional profile. These findings provide valuable insights into the production technique of Zn biofortified microgreens and the potential enhancement of their overall nutritional profile using agronomic biofortification techniques.
Speakers
PP

Pradip Poudel

The Penn State University
Pradip
Co-authors
FD

Francesco Di Gioia

The Penn State University
NA
Friday September 27, 2024 11:15am - 11:30am HST
Nautilus

11:15am HST

CHMG 2 - Consumer Perceptions of Climate-Smart Products
Friday September 27, 2024 11:15am - 11:30am HST
Climate-Smart Agriculture (CSA) is a broad term referring to agricultural production methods which aim to increase productivity whilst building resiliency to the threats associated with climate change and mitigating greenhouse gas emissions. Examples include cover cropping, conservation tillage, agroforestry, and any other methods which support climate change adaptation and mitigation. A critical yet still understudied component of the advancement of CSA lies in understanding how consumers perceive and interact with climate-smart commodities, and with nearly two-thirds (65%) of Americans believing that climate change is a global emergency, a need to investigate what qualities they attribute to “climate-smart” commodities became clear. This study investigates the perceptions of “climate-smart” commodities amongst American consumers through a national survey with consideration of demographic impacts on definitions. Survey questions investigated if consumers were familiar with CSA, what production qualities they perceived as “climate-smart,” and if they were interested in climate-smart commodities. Questions about production methods were categorized into the three main pillars of CSA set forth by the FAO: adaptation, mitigation, and sustainable intensification. The implications for far-reaching climate-smart food policies, marketing/promotional decisions, and sustainability education efforts for Americans are discussed.
Speakers
AL

Abigail Lauterbach

The University of Georgia
Co-authors
avatar for Julie Campbell

Julie Campbell

University of Georgia
Friday September 27, 2024 11:15am - 11:30am HST
South Pacific 1

11:15am HST

FLOR 3 - The Use of Machine Learning to Develop Refined Foliar Tissue Analysis Standards and Diagnostic Tools for for Petunia
Friday September 27, 2024 11:15am - 11:30am HST
Foliar tissue analysis is utilized to diagnose a crop's nutrient status. For most floriculture crops a survey approach of a small population of plants (n= <25) of healthy appearing plants are used to establish sufficient nutrient standards. While this historical approach offers a baseline for the wide variety of floriculture crops there is a need for scientifically based ranges similar to those available in agronomic crops. For fast-maturing crops, utilizing foliar tissue analysis and correctly interpreting the results is critical in making fertility adjustments when problems arise. Foliar tissue analysis results of petunia (Petunia hybrida) were compiled from a variety of diagnostic and research institutions to account for variations of growing environments and classified into five ranges (deficient, low, sufficient, high, and excessive). To aid in foliar tissue analysis interpretation machine learning models were evaluated for accurate percent correct classification (PCC) into the sample's respective nutrient classification. Four separate machine learning algorithms were performed to analyze the data set including sequential minimal optimization (SMO) of support vector machines (SVMs) and multilayer perceptron (MLP) artificial neural network (ANN), and two decision tree models J48 and Random Forest (RF). Machine learning algorithms were compared to identify significant model nutrients based on a complete foliar tissue analysis report of 11 elements for the observations. The performance of both machine learning algorithms SMO and MLP were determined using PCC and during the cross-validation. By evaluating the foliar tissue concentration dataset of multiple species by 10-fold and 66% split cross-validations, the incorporation of five elements of ranked based on Shannon Entropy (Information Gain) was able to correctly classify tissue concentrations into one of five foliar nutrient classifications greater than traditional statistics. This information provides additional insight as to how examining nutrient relationships can assist in identifying fertility problems and classifying nutrient ranges.
Speakers
PV

Patrick Veazie

NC State University
Co-authors
BW

Brian Whipker

NC State University
NA
Friday September 27, 2024 11:15am - 11:30am HST
Kahili

11:15am HST

ORGH 3 - No-till planting organic dry bean into rolled-crimped cover crops
Friday September 27, 2024 11:15am - 11:30am HST
Consumer demand for organic and locally sourced plant-based protein has created an opportunity for farmers in the Northeast and Upper Midwest who are interested in organic dry bean (Phaseolus vulgaris) production. However, standard practices for organic dry bean production can degrade soil health because of the soil tillage and cultivation used for weed management and harvesting. Such soil disturbance is not only labor and fuel intensive, but it also makes soil vulnerable to extreme weather, which is a major concern given the increased frequency of heavy rain events. Building on success with no-till planting soybean into mechanically terminated cereal rye, a team of researchers and stakeholders from Wisconsin, New York, Maine, and Vermont developed a project to assess dry beans for cover crop-based, organic no-till production. In addition to crop yield and profitability, field experiments focused on assessing weed and disease management. Findings from several experiments show that dry beans can successfully emerge through mulch from cover crops and produce yields that are comparable to standard tillage based organic production. In an experiment conducted at two sites in 2020-2021 and 2021-2022, a cover crop mixture of hairy vetch and cereal rye produced relatively high biomass (>7000 kg/ha), which suppressed weeds (< 500 kg/ha) and resulted in relatively high (2500 kg/ha) organic black bean (cv. ‘Zorro’) yield. Results are congruent with previous research showing that mulch from cover crops can suppress weeds, particularly small seeded annual weeds. In an experiment conducted in 2016-2017 and 2017-2018, we showed that mulch from mechanically terminated cereal rye (Secale cereale) can also reduce the incidence of the fungal disease white mold (Sclerotinia sclerotiorum) in organic no-till planted dry bean. Although mulch from cover crops can suppress weeds and soil borne diseases, achieving the high cover crop biomass production that is necessary for suppression can be challenging. A field experiment was conducted in Wisconsin, New York, Vermont, and Maine in 2022-2023 to test the efficacy of interrow mowing weeds that break through the mulch in the space between crop rows. Preliminary results show that interrow mowing has potential to reduce yield loss from weeds and weed seed production in organic no-till planted dry bean production. Additional research is needed to develop management guidelines for no-till planting organic dry beans into rolled-crimped cover crops.
Speakers
MR

Matthew Ryan

Cornell University
Co-authors
EB

Ellen B Mallory

University of Maine
NA
EY

Eric Youngerman

Cornell University
NA
EF

Erika Filer Everest

Cornell University
NA
ES

Erin Silva

UW-Madison
HD

Heather Darby

University of Vermont
NA
KL

Kristen Loria

Cornell Univ
NA
MH

Madeline Hunter

University of Maine
NA
NA

Nazir Adam Sharifi

Cornell University
NA
SP

Sarah Pethybridge

Cornell University
NA
UM

Uriel Menalled

Cornell University
NA
VM

Virginia Moore

Cornell University
NA
Friday September 27, 2024 11:15am - 11:30am HST
South Pacific 3

11:15am HST

VCM 6 - Optimizing Planting Density of Sweet Corn in Georgia
Friday September 27, 2024 11:15am - 11:30am HST
Currently, most sweet corn in the state of Georgia is produced and shipped wholesale for fresh market consumption. The majority of producers in the state aim for a Fourth of July harvest, and shipper sweet corn is a significant source of income for Georgia vegetable growers. Plant population density is a critical factor for achieving optimal yield while balancing resource inputs, and the commercial standard for sweet corn in the state is 60,000 to 74,000 plants ‧ ha-1. While recent research in the midwestern U.S. suggests that planting densities for processing sweet corn can be pushed above previously recommended ranges to optimize profit, little work has been done in current years concerning fresh market shipper sweet corn in the southeastern region of the country, which differs drastically in soil type and seasonal weather patterns. Therefore, the objective of this study is to re-evaluate current state guidelines for plant population density to optimize marketable yields by manipulating inter- and intra-row plant spacing. To do this, sweet corn (cv. ‘Obsession’) was sown directly to the field in the spring season of 2023 at a rate of 43,000 to 107,000 plants ‧ ha-1, which was achieved with sowing patterns in either two or three rows per bed top (91 cm or 46 cm apart, resp.), and five within-row spacings ranging from 15 cm to 25 cm at 2.5 cm increments. The field was managed according to the University of Georgia's irrigation, fertilizer, insect, and disease management guidelines. At harvest, the number, size, and tip fill of ears were collected, with marketable ears categorized based on USDA Fancy grading standards for a minimum length of 15 cm and unfilled kernels at tips covering less than one-fourth cob length. A significant increase in marketable yield was associated with the number of rows but not within-row spacing, with an average increase of 24% in three-row treatments (p < 0.05). There was not a significant difference in unmarketable yield between row treatments. Preliminary results indicate that plant population density for shipper sweet corn in Georgia can be increased by adding a third row while maintaining fresh market quality.
Speakers
HM

Hayley Milner

University of Georgia
Co-authors
JC

Juan Carlos Diaz Perez

University of Georgia
NA

Nirmala Acharya

University of Georgia
NA
SV

Simerjeet Virk

University of Georgia
NA
TM

Ted McAvoy

University of Georgia
NA
Friday September 27, 2024 11:15am - 11:30am HST
South Pacific 2

11:15am HST

VSF 5 - Active vs. Passive Row Cover Management: Impacts on Abiotic Growing Conditions, Yield, and Pests on Overwintering Strawb
Friday September 27, 2024 11:15am - 11:30am HST
Locally produced strawberries have outstanding market potential. Yet their production in the north-central US has declined, partly due to risks associated with the traditional matted-row system. While the plasticulture system offers promise, challenges like plug plant availability in late summer persist. Farmers may choose to use bare-root plants and plant in the summer. However, the high labor demand for planting bare-root plants on plastic and the intensive plant care in the summer have limited the use of plasticulture systems to small-scale operations. High tunnels are widely adapted for strawberry production worldwide. This structure protects plants from strong winds and rainfall, providing additional heat units and moderate frost protection. Successful implementation in Indiana, particularly with fall-planted strawberries, has demonstrated significant yield potential. In our initial exploration, an active row cover management strategy, i.e., covering and uncovering the plants daily in the winter months according to temperatures, was employed during winter months. Although the management approach optimized the winter environment for plant growth, it added labor in crop management, and it may not be feasible for farmers who are not on-site during winter months. This study compares four winter cover management strategies in the 2021-2022 and 2022-2023 seasons: No cover (row covers were not used in the entire winter), Active with hoops (row covers were actively managed daily and placed on hoops), Passive with hoops (the beds were covered during the coldest period, row covers were not removed during the day and were placed on hoops), and Passive without hoops (the beds were covered during the coldest period, row covers were not removed during the day and were placed directly on plants). The study found that No cover resulted in lower minimum temperatures and higher average daily PAR. The active management treatment exhibited the highest relative humidity. Marketable strawberry yields were not significantly different among the covering treatments. However, aphid density was notably higher under covers compared to the no-cover treatment. Our findings indicate that active row cover management during winter was not necessary in the strawberry production system, as it did not significantly increase yield compared to passive management strategy or absence of row covers. Furthermore, the passive management strategy, while potentially advantageous in terms of temperature regulation, was not recommended due to the associated risk of elevated aphid populations.
Speakers
WG

Wenjing Guan

Purdue University
Co-authors
LI

Laura Ingwell

Purdue University
NA
SW

Samantha Willden

Purdue University
NA
Friday September 27, 2024 11:15am - 11:30am HST
Coral 3

11:15am HST

WCPM 4 - Are selective insecticides compatible with Bemisia tabaci biocontrol efforts in controlled environments?
Friday September 27, 2024 11:15am - 11:30am HST
Generalist predators are known for their significant contribution to suppression of major crop pests in controlled environments and beyond. Given that insecticides are one pillar of many Integrated Pest Management (IPM) programs, their compatibility with biocontrol efforts is essential for developing a successful IPM program. Knowledge gaps persist regarding selective insecticides' non-target impacts on whitefly natural enemies that can jeopardize its biocontrol efforts. In this study, we exposed adult predators to commercially available insecticides (Cyantraniliprole and Pyriproxyfen) using multiple laboratory approaches to assess their effects on survivorship, predation, and changes in prey selection in response to insecticides. Two major whitefly predators were evaluated including, Hippodamia convergens (Coleoptera: Coccinellidae) and Geocoris punctipes (Hemiptera: Geocoridae), to estimate survivorship and consumption of whitefly nymph, Bemisia tabaci (Hemiptera: Aleyrodidae). Our result indicates that while pyriproxyfen had a negligible effect on the predators, cyantraniliprole exposure directly affected H. convergence by reducing survivorship duration and indirectly influenced both predators by reducing prey consumption and altering prey preference. Overall, pyriproxyfen demonstrated minimal impact on predators, while cyantraniliprole adversely influenced mortality and indirect foraging effects under controlled laboratory conditions. Hence, our findings highlight that even highly selective insecticides could have a sub-lethal impact on natural enemies, jeopardizing their contribution to pest control, and warranting future efforts to better integrate them into IPM programs.
Speakers Co-authors
AP

Albertha Parkins

University of Georgia
NA
JM

Jason M Schmidt

University of Georgia
NA
Friday September 27, 2024 11:15am - 11:30am HST
South Pacific 4

11:30am HST

CE 7 - Evaluation of Liquid Organic Fertilizers for Containerized Production of Leafy Greens in a Controlled Environment
Friday September 27, 2024 11:30am - 11:45am HST
Organic farming practices, such as the use of organic substrates, fertilizers, pesticides, and biological control, are gaining popularity in controlled environment agriculture (CEA) since soilless production was approved for organic certification in the US. Our past study showed that liquid organic fertilizers are more effective than substrate-incorporated compost fertilizers. Although many liquid organic fertilizers are commercially available, they vary widely in their nutritional composition. Therefore, selection of a suitable fertilizer can be complicated and confusing for CEA growers. The current study aimed to evaluate the effectiveness of different liquid organic fertilizers and compare their performance with that of a synthetic fertilizer for growing lettuce in two different containerized hydroponic systems. Two greenhouse experiments were conducted in a randomized block design with five replicates. In Experiment 1, two types of container (regular container and Dutch bucket) and three fertilizers (earthworm castings and kelp (ECK), molasses with other natural plant extracts (MPE), and hydrolyzed fish protein (HFP)) were considered. The fertilizers were selected from the Organic Materials Review Institute (OMRI) list based on their nutrient profile and reports from other studies. In Experiment 2, selected liquid organic fertilizers (ECK, MPE) were compared with a commercial synthetic fertilizer (CSF). In Experiment 1, ECK performed better, resulting in 28% greater fresh weight, 20% greater dry weight, 48% greater leaf area, 26% greater shoot width, 126% greater average root fresh weight, and 47% greater root length in containerized production compared to the Dutch bucket system. No significant growth difference was observed between MPE and HFP. In Experiment 2, there was no significant growth difference between ECK and CSF; however, the shoot width, leaf area, and dry weight of lettuce were significantly lower with MPE treatments compared to ECK. Results show that ECK performed similarly or better than synthetic fertilizer for growing lettuce in these container hydroponic systems. The findings of this study indicate that a single organic fertilizer could be used instead of several for organic leafy green production in soilless substrate.
Speakers
US

Uttara Samarakoon

The Ohio State University
Co-authors
JM

Joanna Moine

The Ohio State University
NA
MC

Milon Chowdhury

The Ohio State University
OW

Oliver Watson

The Ohio State University
NA
Friday September 27, 2024 11:30am - 11:45am HST
Nautilus

11:30am HST

CHMG 2 - Setting Priorities for Managing Extension Work and Home Life
Friday September 27, 2024 11:30am - 11:45am HST
Extension careers are uniquely challenging for work/life balance. Extension professionals frequently work with stakeholders outside the university and spend a significant amount of time traveling to give presentations and build relationships. In consumer horticulture, an added stress is that most educational programming is scheduled for evenings and weekends. Overflowing email inboxes further compound the stress. High rates of exhaustion and burnout have been documented in Extension professionals. The problem is one of high demand and limited resources. Extension professionals are expected to navigate the problem of scarce resources by individually setting priorities and saying no to low impact requests. A new prioritization method will be introduced that is based upon real estate appraisal law. The highest and best use analysis can be adapted for setting priorities for the busy Extension professional regardless of career stage. This session will emphasize amending position descriptions to articulate clear boundaries, setting aside time to be physically and mentally rested, and prioritizing high impact projects. The highest and best use analysis is meant to be customized for each individual and takes into account unique traits such as introversion/extroversion, age, and topic expertise.
Speakers
avatar for Esther McGinnis

Esther McGinnis

Extension Horticulturist/Director of the Extension Master Gardener Program, North Dakota State University
I am an Associate Professor within the Department of Plant Sciences and the Director of the NDSU Extension Master Gardener Program.
Friday September 27, 2024 11:30am - 11:45am HST
South Pacific 1

11:30am HST

FLOR 3 - Increasing the Nighttime Lighting Duration Can Hasten Flowering of Long-day Plants
Friday September 27, 2024 11:30am - 11:45am HST
Low-intensity (≈ 2 μmol·m−2·s−1) photoperiodic lighting is often delivered at night to promote flowering of long-day greenhouse ornamentals when natural days are short. Adding sufficient far-red (FR) light to red (R) light is necessary for the most rapid flowering in some crops, including snapdragon (Antirrhinum majus) and petunia (Petunia × hybrida). Specialty light-emitting diodes (LEDs) that include R FR light are effective at floral promotion but cost-prohibitive, whereas common warm-white (WW) LEDs lack sufficient FR light and can delay flowering. Because the duration to saturate flowering is longer than currently used (e.g., 4–8 hours) for some long-day plants, we conducted a replicated greenhouse experiment to determine how the WW or R FR LED lighting duration influenced flowering. We grew snapdragon ‘Liberty Classic Yellow’, petunia ‘Easy Wave Burgundy Star’, and petunia ‘Wave Purple Improved’ under truncated 8-hour natural short days with or without WW or R FR (1:1) LEDs operating for 0, 4, 8, 12, or 16 hours in the middle of each night throughout the experiment. Snapdragon flowered 13–16 days earlier under R FR LEDs than under WW LEDs regardless of the lighting duration. Increasing the lighting duration from 0 to 16 hours decreased flowering time by up to 16 days and decreased plant height and leaf number at flowering under R FR LEDs, but not under WW LEDs. For petunia ‘Easy Wave Burgundy Star’, although WW LEDs delayed flowering by 6–13 days but promoted lateral branching compared to R FR LEDs, the gap in flowering time narrowed as the lighting duration increased from 4 to 16 hours. Increasing the lighting duration improved the efficacy of WW LEDs, but not R FR LEDs. Flowering of petunia ‘Wave Purple Improved’ was unaffected as the lighting duration increased from 4 to 16 hours regardless of the lamp type and was delayed by 6–10 days under WW LEDs than under R FR LEDs. For both petunia cultivars, flowering time was similar under 16-hour WW LEDs and 4-hour R FR LEDs. In conclusion, increasing the nighttime lighting duration increased the efficacy of WW LEDs at promoting flowering of petunia and increased the efficacy of R FR LED lamps at promoting flowering of snapdragon. Delivering WW LEDs all night long can minimize flowering delay in petunia compared to R FR LEDs. In contrast, sufficient FR light was indispensable to promote flowering of snapdragon, for which WW LEDs were ineffective.
Speakers
QM

Qingwu Meng

University of Delaware
Co-authors
TK

Thomas Kramer

University of Delaware
NA
Friday September 27, 2024 11:30am - 11:45am HST
Kahili

11:30am HST

VCM 6 - Boosting Sweet Corn Yields: The Power of Biochar and Fertilizers Unveiled
Friday September 27, 2024 11:30am - 11:45am HST
This study explored the efficacy of biochar, derived from paper mill waste, in enhancing soil properties, plant growth and yield in sweet corn when used with organic (poultry litter) or inorganic fertilizers. Conducted in spring 2023, the field trial assessed biochar application rates (0, 10, 15, and 20 tons/acre) combined with fertilizers supplying 225 lbs N/acre in a randomized complete block design with four replications. Our results indicate that biochar's effectiveness is limited when used alone but significantly affects soil nutrients and crop outcomes in combination with fertilizers. Inorganic fertilizers, compared to organic, were more effective in improving yield metrics such as ear number, weight, and width. In addition, our findings suggest that the interaction of biochar and fertilizer type significantly influences soil nutrient levels. Biochar and inorganic fertilizer generally exhibited a strong negative correlation with nutrients like nitrogen (N), indicating a notable decrease in N soil content with lower biochar application rates. Suggesting that biochar can mitigate nutrient depletion when combined with inorganic fertilizers. Conversely, when biochar is applied alongside organic fertilizers, the outcomes vary across different nutrients. For magnesium (Mg) and calcium (Ca), positive correlations emerge at higher application rates, hinting at biochar's role in enhancing the bioavailability of these nutrients in organically fertilized soils. Regarding plant growth and development, the analysis revealed that the interaction between fertilizer type with biochar and biochar rate alone had no significant effect on most measured growth parameters. However, the fertilizer type used did significantly affect some growth parameters. Specifically, plants grown with organic fertilizer had significantly higher fresh weight of roots and total dry plant weight than those grown with inorganic fertilizer. It was found that the highest rate of biochar (20 tons/A) raised soil pH significantly at 90 days, reaching 6.65 pH in the inorganic treatment and 7.0 pH in the organic treatment. The pH was lowest in the treatments without biochar (0 tons/acre) at 90 days after application (5.1 pH inorganic and 6.0 pH organic treatments respectively). Furthermore, biochar application was linked to increased soil microbial activity, as evidenced by CO2 burst measurements. These significantly rose with higher biochar rates under both fertilizer regimes, albeit without a significant interaction effect between biochar and fertilizer type on CO2 burst. These findings suggest that integrating biochar with fertilization strategies can enhance soil health and sweet corn production, offering a sustainable approach to managing soil nutrients and improving crop yield.
Speakers
avatar for Emilio Suarez Romero

Emilio Suarez Romero

Research Assistant, University of Georgia
Co-authors
HY

Henry Y Sintim

University of Georgia
NA
JC

Juan Carlos Diaz Perez

University of Georgia
KC

Kate Cassity Duffey

University of Georgia
NA
TM

Ted McAvoy

University of Georgia
NA
Friday September 27, 2024 11:30am - 11:45am HST
South Pacific 2

11:30am HST

VSF 5 - Performance of Containerized Strawberries (Fragaria x ananassa Duch.) in a Greenhouse Environment
Friday September 27, 2024 11:30am - 11:45am HST
The horticulture industry has seen an increase in the use of greenhouses as an alternative protected systems to grow strawberries (Fragaria ×ananassa Duch.). Growing strawberries in a greenhouse provides the opportunity for earlier and out-of-season harvesting. However, there is limited research on the phenological and physiological performance of strawberries grown in containers under greenhouse conditions. Therefore, this experiment aims to evaluate the phenological and physiological performance of containerized strawberries grown in a greenhouse. In this study, two day-neutral strawberry cultivars, ‘Albion’ and ‘San Andreas’, were planted in 1-gallon nursery pots using 100% pine bark substrate and evaluated for a 5-month growing season. The phenological stages of all flower buds were recorded daily on five selected plants per cultivar. Monthly data was collected on biomass and diurnal photosynthesis. The yield of all plants was recorded, and fruits were separated into marketable and culled categories. During mid-season plants became infected with black root rot (Pythium spp.), and the results reflect the effects of the disease progression. Although the flower phenology was similar between cultivars throughout the production cycle, differences were observed in biomass accumulation and yield. ‘San Andreas’ showed higher growth over time and a decreased proportion of cull fruits during the Pythium infection. The cultivars evaluated showed similar trends in physiological processes, such as assimilation rate, evapotranspiration, intercellular carbon, stomatal conductance, leaf vapor pressure deficit, and quantum efficiency of photosystem II. Although not consistent, ‘San Andreas’ showed significantly higher values for some physiological parameters. These results indicate that strawberry growth and yield differ between cultivars in the greenhouse environment, which could be related to physiological factors that can ultimately translate to differences in disease susceptibility and performance The initial preliminary results of the first experiment indicates that strawberries can be cultivated with satisfactory results in a greenhouse. This alternative method can offer extended growing seasons, allowing for controlling environments, better disease control management, and easier pest control. Moreover, the portability of containers provides flexibility for the producer to arrange plants for space utilization.
Speakers
CB

Caroline Blanchard

Research Associate III, Auburn University
Co-authors
BC

Bernardo Chaves Cordoba

Auburn University
NA
MR

Melba Ruth Salazar Gutierrez

Auburn University
NA
Friday September 27, 2024 11:30am - 11:45am HST
Coral 3

11:30am HST

WCPM 4 - Plants Under Regulation; A North Carolina Perspective
Friday September 27, 2024 11:30am - 11:45am HST
State and federally regulated weeds pose significant challenges to agricultural economies worldwide, impacting crop yields, production costs, and overall farm profitability. Some estimates have their economic impact upwards of $30 billion dollars annually. Regulated plants can encroach upon public and private property, and cultural and recreational areas, which not only diminishes their aesthetic appeal and usability, but also displaces other native plants and animals. State and federal regulatory agencies operate within a legal framework for setting rules that allow for the control of regulated plants. Regulatory rules apply measures that help preserve these public and private spaces by addressing infestations of noxious plants. Management strategies of active infestations can range from controlling future or current spread to full on eradication. While eradication of a noxious plant may be the gold standard to strive for, it is also the most time consuming and costliest strategy. Often, two commonly employed solutions, aside from eradication, are; either managing or controlling an infestation. Managing is where the infestation isn’t increasing in geographic area. The periphery is fought to limit further spread. Controlling an infestation goes beyond managing, where a push is made to reduce the geographic area and steers the infested area toward an eradication track. The more stringent (eradication) a strategy becomes, the higher the cost and the longer it will take. The classic invasion curve describes this situation perfectly where the longer an infestation goes before it is identified, the more expensive and longer it will take to eradicate, if at all. Chemical applications, IPM and cultural control mechanisms are used to fight active infestations. Other tools in the regulatory tool bag include inspection of agricultural commodities and issuance of phytosanitary certificates, nursery inspections and certification, active survey and the use of quarantines and limited research permits. North Carolina has multiple active projects working towards eradication and control. Witchweed (Striga asiatica) populations have been present in NC and SC since its introduction in 1955. Witchweed, if left unchecked, has the potential to devastate the midwestern corn belt, which was the primary reason for its regulation. At that time North Carolina had approximately 400,000 infested acres. Today we have 2,000 infested acres. Other noxious weeds on the eradication path are wooly frogsmouth (Philydrum lanuginosum) and yellow floating heart (Nymphoides peltata). Both species have been aggressively treated in their limited distribution within the state.
Speakers
JD

Jarred Driscoll

North Carolina Dept. of Ag.
Friday September 27, 2024 11:30am - 11:45am HST
South Pacific 4

11:45am HST

FLOR 3 - Extended Storage of Cut Flowers Using Sub-zero Temperature
Friday September 27, 2024 11:45am - 12:00pm HST
The cut flower industry needs postharvest techniques that allow for extended storage of fresh cut flowers to meet consumer demands. We evaluated the use of sub-zero storage temperature (-0.6 °C) to maintain viable flowers with improved or comparable vase life to flowers stored at the industry standard (4 °C) without sacrificing aesthetic appeal. The vase life of 17 commercially important cut flower species: alstroemeria, anemone, campanula, carnation, chrysanthemum, delphinium, freesia, gerbera, gypsophila, larkspur, lily, lisianthus, ranunculus, rose, stock, sunflower, and tuberose, when stored dry at -0.6 °C for durations of 4, 8, and 12 weeks was comparable to or longer than when stored at 4 °C. Tuberose stems were not viable after holding for any storage duration or temperature. Stems of carnation benefited from an 8-hour pre-storage pulse with a hydrating solution and maintained a similar vase life to non-stored control stems when stored for 4 weeks at -0.6 °C. Conversely, rose stems only maintained similar vase life to non-stored control stems when held at 4 °C for all pre-storage pulsing solutions (water, hydration or holding solution). Vase life of lily and chrysanthemum declined for all pre-storage pulsing solutions and stems only remained viable after 8 weeks storage when held at -0.6 °C. Additionally, stored chrysanthemum and lily stems had a longer vase life when stored at -0.6 °C than when held at 4 °C after 4- and 8-weeks storage, respectively, for all pre-storage pulsing solutions. Experiment 3 further evaluated carnation, lily, and rose stems with and without a pre-storage acclimation period at 4 °C for either 24 hours or 1 week prior to extended storage durations of 4, 6, or 8 weeks. Holding stems at 4 °C for 1 week prior to extended storage reduced vase life of all species. Rose stems remained viable after 8 weeks of extended storage when held at -0.6 °C, but only when no pre-storage hold was used. Lily and rose stems were not viable beyond 4-week storage durations when held at 4 °C, but remained viable with no pre-storage holding period after 8 weeks at -0.6 °C. Carnation stems maintained longer vase life irrespective of a pre-storage holding period when stored at -0.6 °C. Through this work we show that that many species of cut flower may be held at sub-zero temperature with improved or comparable vase life to the industry standard of 4 °C.
Speakers
JD

John Dole

North Carolina State University
Co-authors
JK

Jennifer Kalinowski

North Carolina State University
NA
Friday September 27, 2024 11:45am - 12:00pm HST
Kahili

11:45am HST

VSF 5 - Influence of Soil Disinfestation and Beneficial Bacterial Treatments on Anthracnose Fruit Rot Disease and Strawberry Yield
Friday September 27, 2024 11:45am - 12:00pm HST
Anthracnose fruit rot (AFR) caused by Colletotrichum acutatum is a major strawberry pathogen in the U.S. affecting both perennial and annual systems. This pathogen can survive in the soil rhizosphere from the previous seasons. Anaerobic soil disinfestation (ASD), an alternative to chemical fumigation methods, has been shown to effectively suppress a wide range of soilborne pests. Beneficial bacteria, such as Bacillus spp., are important biocontrol agents due to their capacity to reduce the growth of pathogens while also promoting plant growth. We proposed that ASD, beneficial bacteria, and their combinations could reduce fruit rot diseases of strawberries and improve crop yield and fruit quality parameters. A trial was conducted using a split-plot design with four replicates at the Hampton Roads AREC, Virginia Beach, VA. ‘Chandler’ strawberry plug plants were planted in various treatments as stated below: non-disinfested field plots (Control); field plots treated with Pic-Clor60 at 196 kg/ha (preplant soil fumigant) (Pic); field plots treated with ASD alone. Additionally, strawberry plants in each of these main treatments were treated with one of the following sub-treatments: no beneficial bacteria (untreated control), Bacillus velezensis only; TerraGrow (a mixture of five Bacillus spp.) at 1.7 kg/ha only; and TerraGrow 1.7 kg/ha applied 4 hours post Oxidate 5.0 (27% hydrogen peroxide, 5% acetic acid and 5% peroxyacetic acid) at 23,385 L/ha. Fruits were harvested twice per week starting 5 April through 20 June, 2023. Harvested fruits in each replicate or sub-plot were sorted into marketable and non-marketable categories. Non-marketable fruits included diseased fruits, small fruits or deformed fruits. Fruit weights were summed for the season by replicate and expressed as g/plant. Fruit firmness and total soluble solids (TSS) were measured on five representative marketable fruits per replicate once per harvest week and data were averaged for the season. For AFR, the weight of diseased fruits decreased significantly in sub-plots treated with B. velezensis, TerraGrow, and TerraGrow post Oxidate compared with the untreated control. In general, the ASD treatment significantly decreased the weight of AFR diseased fruits compared to the control and Pic-Clor 60 fumigation treatments. Fruit from ASD treated plots showed increased firmness and higher Total Soluble Solids values compared to Pic-Clor 60 plots. However, the marketable and total yield was lower in the ASD plots compared with other treatments. Our findings indicate that the utilization of beneficial microorganisms with ASD has the potential to reduce fungal diseases in annual hill strawberry production system.
Speakers
avatar for Jayesh Samtani

Jayesh Samtani

Associate Professor, Virginia Tech
Co-authors
BA

Baker Aljawasim

Virginia Tech
NA
CM

Chuansheng Mei

Institute for Advanced Learning and Research
GY

Gabriel Yeboah

Virginia Tech, Hampton Roads AREC
NA
PR

Patricia Richardson

Virginia Tech, Hampton Roads AREC
NA
RC

Robert Chretien

The Institute for Advanced Learning and Research
NA
SL

Scott Lowman

The Institute for Advanced Learning and Research
NA
Friday September 27, 2024 11:45am - 12:00pm HST
Coral 3

12:00pm HST

CHEX 2 - The Kentucky Small Fruits Initiative: An Extension-Industry Partnership
Friday September 27, 2024 12:00pm - 12:15pm HST
Growers in Kentucky are increasingly interested in adding small fruit crop enterprises to their farming operations. While consumer demand is high, available capital and limited production knowledge are known barriers for small- and mid-scale producers interested in growing and selling these crops. The Kentucky Horticulture Council (KHC) and the University of Kentucky (UK) partnered on a financial and technical assistance support program for Kentucky growers with an interest in producing these crops. Over the 4-year project, more than $936,000 was invested in on-farm projects, working with 275 existing and 76 pre-commercial growers in 89 different counties across the state. Blackberry, blueberry, and strawberry were the highest demand crops. Irrigation, trellising, and netting were the most requested non-plant material inputs. The expected farm impact over the next 10 years will exceed $7.4M, based on yield and sales price estimates. The funding model providing financial assistance to current and prospective growers along with extension’s role in delivering research-based information and providing technical assistance will be discussed. The presentation will also focus on strategies to recruit and screen program participants by assessing needs, setting realistic expectations, increasing production knowledge and skills, with the goal of fostering satisfaction and meeting the intended project objective of increasing small fruit crops profitability for commercial sales over the next decade and beyond.
Speakers
CF

Cindy Finneseth

Kentucky Horticulture Council
Co-authors
DB

Daniel Becker

University of Kentucky
NA
DS

Delia Scott

University of Kentucky
NA
SW

Shawn Wright

University of Kentucky
NA
Friday September 27, 2024 12:00pm - 12:15pm HST
South Pacific 2

12:00pm HST

HIH - Therapeutic Horticulture and Chronic Lower Back Pain: A Pilot Study at the University of Florida
Friday September 27, 2024 12:00pm - 12:15pm HST
The specific aims of this pilot study were to 1) determine if and which patients, receiving care for chronic lower back pain (LBP) in the UF Health Comprehensive Spine Center, were interested in therapeutic horticulture to manage LBP, and 2) quantify changes in LBP, functional tasks, and anxiety upon completion of a therapeutic horticulture session. The study hypothesis was that individuals participating in the therapeutic horticulture intervention would demonstrate improvements in spine mobility and physical function as well as a reduction in spine pain severity from pre- to post-session. This was a two-part study with a mixed methods design including cross-sectional survey and pilot experimental components. Results revealed that 68% of patients were interested in learning about therapeutic horticulture for LBP. Among those patients who participated in the intervention, improvements were observed in anxiety, spine flexion, and spine rotation to the left.
Speakers
avatar for Elizabeth Diehl

Elizabeth Diehl

Director of Therapeutic Horticulture, University of Florida
The mission of the University of Florida’s Therapeutic Horticulture Program at Wilmot Botanical Gardens is to improve lives through engaging with plants and nature. The program is situated at the nexus of the gardens’ commitment to patient care, education, and research, drawing... Read More →
Friday September 27, 2024 12:00pm - 12:15pm HST
South Pacific 1

12:00pm HST

VGBR 3 - Evaluation of Vegetable Soybean Breeding Lines for Yield and Related Traits
Friday September 27, 2024 12:00pm - 12:15pm HST
Vegetable soybean (Glycine max), also known as edamame, is a specialty soybean that is harvested at R6 growth stage. Vegetable soybean has steadily increased in acreage and market demand although it is relatively new to North America. It is of significance to develop new cultivars that are more adapted to local environment and crop management system to promote specialty crop production and meet the market requirements. In this study, 14 genotypes of vegetable soybean, including 10 breeding lines and 4 check cultivars, were evaluated during 2020-2023 for potential uses as edamame. There were significant differences among genotypes in both fresh pod and mature seed yields, agronomic and seed composition traits investigated. The year effects and genotype x year interactions were also significant in most cases. Fresh pod yield averaged 11,227.5 kg ha-1, ranging 9,800.1 – 13,154.3 kg ha-1, and mature seed yield averaged 2,814.7 kg ha-1, ranging 2,029.2 – 3,175.2 kg ha-1. The average 100-seed weight of 14 genotypes was 26.9 g, ranging 23.1 – 30.1 g. Maturity averaged 153.3 days after planting, ranging 147.1 – 159.5 days. On a dry weight basis, seed protein, oil and sucrose contents averaged 43.5%, 18.7% and 5.0%, respectively. The estimates of broad-sense heritability were medium to high (66.82 – 94.90%) for most of the traits, while the heritability estimates for fresh pod yield and duration from flowering to maturity were relatively low (23.44% and 42.29%). Several breeding lines exhibited good yield, larger seed size, higher contents of protein, oil, oleic acid and sulfur-containing amino acids, suggesting the potential of release and commercial production.
Speakers
GJ

GuoLiang Jiang

Virginia State University
NA
Friday September 27, 2024 12:00pm - 12:15pm HST
South Pacific 4

12:00pm HST

VSF 5 - Effect of Temperature and Light during Cold Storage of Strawberry Liners
Friday September 27, 2024 12:00pm - 12:15pm HST
Identifying storage conditions for strawberry liners propagated in controlled environments is needed to enable mass production of plant material for field growers. The objective was to compare the effect of crown diameter (CD), light, and temperature during cold storage (CS) on growth and subsequent yield of ‘Albion’ strawberry liners propagated indoors for 4 weeks under 24 or 16 h·d–1 (experiments 1 and 2, respectively) using white light-emitting diode fixtures. After propagation, plants of two CD (small 10mm) were stored during 4 weeks under 24 temperatures (ranging from -2 to 7 C) and 47% relative humidity, with or without 5 μmol·m–2·s–1 of white light provided for 24 h·d–1. Plants were moved to a common greenhouse compartment after each CS experiment and grown for 8 weeks to evaluate carryover effects on fruit yield. Overall, shoot and root dry mass were lower in plants exposed to CS compared to the initial baseline material, indicating a general loss of biomass during CS, regardless of treatment. The use of light did not affect any of the parameters evaluated, indicating that liners can be stored under darkness. In experiment 1, plants with large CD had higher chlorophyll concentration than those with small CD, but the opposite trend was measured in experiment 2. As expected, plants with large CD had longer petioles and produced more shoots during CS than those with small CD, regardless of experiment. Plants stored under ≤ -1.4 or -1.9 °C for experiments 1 and 2, respectively, died during the carryover phase, suggesting that liners should not be stored at or below these low temperatures. However, no treatment differences were measured after the carryover phase for plants stored in all other treatments. Further results highlighting the effect of temperature during CS will be presented.
Speakers
LD

Lian Duron

Purdue University
Friday September 27, 2024 12:00pm - 12:15pm HST
Coral 3

12:15pm HST

CHEX 2 - Case Study: Assessing Workforce Training Needs And UMKC Student Interest To Develop Controlled Environment Agriculture Education In Kansas City
Friday September 27, 2024 12:15pm - 12:30pm HST
Controlled environment agriculture (CEA) integrates technology to optimize crop performance. The project goal was to inform the development of CEA curriculum by understanding CEA workforce training needs and gauging student interest at the University of Missouri – Kansas City (UMKC). CEA industry surveys determined the knowledge/skills needed for employment and educational expectations. A second survey was sent to UMKC students to gauge their knowledge of/interest in a CEA educational program. The top five positions in demand by the CEA industry were: (1) manager, (2) worker, (3) research
Speakers
avatar for Juan Cabrera-Garcia

Juan Cabrera-Garcia

Research Assistant Professor & State Extension Specialist, University of Missouri
My extension program focuses on providing research-based resources, trainings, and tools to beginning and established specialty crop growers. Check our programs focused on controlled environment agriculture (Veteran Farmers (umkc.edu)) and commercial horticulture (Commercial Hort... Read More →
Co-authors
AC

Angela Cottrell

University of Missouri - Kansas City
NA
CM

Caroline Matz

University of Missouri - Kansas City
NA
KC

Karin Chang

University of Missouri - Kansas City
NA
Friday September 27, 2024 12:15pm - 12:30pm HST
South Pacific 2

12:15pm HST

HIH - Integrating Developmentally Disabled Individuals Into the Oklahoma Green Industry Workforce
Friday September 27, 2024 12:15pm - 12:30pm HST
Horticulturists throughout the State of Oklahoma have a long history of interacting, mentoring, and often employing individuals with developmental disabilities. Young adults seeking vocational training in western Oklahoma have access to the Center of Family Love, Okarche, OK, whereas individuals and their families enjoy similar training opportunities in eastern Oklahoma utilizing services and programs offered by A New Leaf, Tulsa, OK metropolitan area. While not an exhaustive list of Oklahoma organizations that offer horticultural therapy and employment opportunities for the developmentally disabled, the two aforementioned businesses have a multidecade track record of successfully matching individuals' talents and skills with specific horticultural-type employment. Not only do clients/workers have opportunities to learn more about growing and marketing both ornamental and edible crops, but they also earn wages while being mainstreamed with the “growing public”. An overview of the genesis of these operations and how they have evolved over time will be highlighted. Lastly, examples will be outlined regarding how workers provide a learning opportunity for their clientele (consumers). Specifically, the public is exposed to and thus recognizes often overlooked value in people that have been wrongfully labeled and assumed not capable of commercial horticultural work activities/tasks, successful interaction with the public, and ultimately the ability to often acquire independent living skills.
Speakers
MS

Mike Schnelle

Oklahoma State University
Friday September 27, 2024 12:15pm - 12:30pm HST
South Pacific 1

12:15pm HST

VGBR 3 - Could Broccoli's Ancestral Lineage Hold the Key to Increased Fatty Acid Content?
Friday September 27, 2024 12:15pm - 12:30pm HST
In the pursuit of agricultural productivity, generations of breeding have often prioritized yield-related traits, inadvertently leading to the loss of desirable genetic traits linked to nutritional content. This phenomenon, known as the genetic lag effect, has implications for human health, particularly concerning the availability of essential nutrients such as omega-3 fatty acids. As omega-3 fatty acids are crucial for various aspects of human health, including heart health, cognitive function, and hormone regulation, it is imperative to explore alternative sources beyond traditional fish-derived options. The demand for plant-based alternatives is rising due to dietary preferences and concerns over fish oil production, emphasizing the need to investigate alternative sources of omega-3 fatty acids. Broccoli, with its rising consumption and rich nutritional profile, presents a promising avenue for addressing this need. For humans, the ideal ratio of omega 6 to omega 3, is 1:1. Yet, the American diet offers an astonishing 30:1 ratio! Broccoli has a ratio of 1:3 ratio. This is comparable to fish ranging from 1:1 to 1:7. Despite its potential, most broccoli breeding programs have focused primarily on grower-oriented traits rather than those beneficial to human health. Thus, there is an opportunity to enhance the nutritional content of broccoli, particularly its omega-3 fatty acid profile, to offer greater health benefits to consumers. This study investigates the omega-3 fatty acid profiles of 35 lines, 9 elite and 26 landrace broccoli cultivars, to address the pressing need for nutrient-rich foods. Our research employs lipid extraction from various tissues of broccoli plants, including bouquets, stems, and leaves. The lipid sample is screened using Gas Chromatography-Mass Spectrometry (GC-MS) for precise quantification and identification of fatty acids. Preliminary results reveal significant variation in omega-3 fatty acid content, specifically levels of alpha-linolenic acid (ALA) among the broccoli lines studied, highlighting the potential for breeding programs to select and develop varieties with enhanced nutritional profiles. By prioritizing consumer-oriented traits in crop breeding, such as omega-3 fatty acid content, we aim to contribute to developing biofortified broccoli varieties that offer sustainable and health-promoting dietary options. This research underscores the importance of diversifying food sources and prioritizing human health outcomes in agricultural practices to address evolving dietary needs and promote overall well-being.
Speakers
AK

Alaina Kleine

University of Florida
NA
Co-authors
Friday September 27, 2024 12:15pm - 12:30pm HST
South Pacific 4

12:30pm HST

CHEX 2 - Assisting Florida Sod Producers with Protecting Water Quality by Quantifying Nutrient Inputs and Exports
Friday September 27, 2024 12:30pm - 12:45pm HST
Adherence to the Florida Department of Agriculture's (FDACS) Best Management Practices (BMP) program is crucial for sod producers to protect water quality. Challenges arise due to perceived low fertilization rates and accelerated production cycles, particularly in South Florida. Challenges are exacerbated by the nutrient export that occurs when harvested sod carries away soil-bound nutrients and residual fertilizer. The sod BMP manual is undergoing revision, with a proposed emphasis on achieving a nutrient balance of nitrogen (N) and phosphorus (P) inputs/exports in sod operations. However, current published data on nutrient export needs to be more comprehensive, necessitating research efforts to fill this knowledge gap. This project, funded by a 2022-2023 FDACS BMP grant, aims to educate and improve sod producer BMPs by assessing current practices and quantifying nutrient inputs/exports through sod slab analysis. A Qualtrics survey was designed to measure sod producers' current BMP practices. Visits to sod farms were employed to collect sod slab samples for nutrient inputs/exports data processing. Results, particularly regarding N and P export, revealed variability across turfgrass species, highlighting the need for further research to determine nutrient sinks and explore the influence of soil depth on nutrient export during harvest. The project's future focus involves providing targeted training based on results to Florida sod producers and exploring additional funding opportunities to address remaining key questions. Results of this project will improve nutrient management inputs/exports budgeting by sod producers and facilitate adoption of practices that improve nutrient management for sod production statewide.
Speakers
avatar for Bonnie Wells

Bonnie Wells

Extension Agent III, University of Florida IFAS Extension
Bonnie Wells is the Commercial Horticulture Agent for the University of Florida IFAS Extension in Brevard County where she specializes in turfgrass and ornamental production and sustainable landscape maintenance. She is a Doctor of Plant Medicine (UF ’13) with more than 20 years... Read More →
Co-authors
AL

Alex Lindsey

University of Florida
BU

Bryan Unruh

University of Florida
NA
KK

Kevin Kenworthy

University of Florida
NA
MS

Marco Schiavon

University of Florida
MT

Mark Tancig

University of Florida IFAS Extension
NA
MV

Matthew VanWeelden

University of Florida IFAS Extension
NA
Friday September 27, 2024 12:30pm - 12:45pm HST
South Pacific 2

12:30pm HST

HIH - The Effect of a Plant Distribution and Care Program on First-Year University Student Retention, Levels of Depression, Stress, Anxiety, and Loneliness
Friday September 27, 2024 12:30pm - 12:45pm HST
The retention and recruitment of freshmen students transitioning to higher education or transferring to new institutions represent significant challenges for universities nationwide. Research underscores the mental health challenges encountered by students upon entering higher education, highlighting the necessity for effective resolution strategies. This study aimed to assess the impact of a plant distribution and care program on first-year university student retention, as well as levels of depression, stress, anxiety, and loneliness. The study employed a treatment and control group, both of which underwent pretest and posttest assessments using the DASS-21 and UCLA Loneliness scale, along with demographic information and prior experiences with mental health issues and plants. Recruitment for both groups was conducted through convenience sampling across university students. The treatment group participated in an 8-week program where they received designated plants and were instructed to care for them within their dormitories using plant care tips provided through an online platform. Additionally, they engaged in greenhouse activities. Conversely, the control group underwent pretest and posttest assessments at the same intervals as the treatment group, without any intervention. Results revealed a significant improvement in mental health among participants in the treatment group, despite data collection coinciding with final semester exams. Conversely, the control group exhibited no discernible differences between pretest and posttest assessments. These findings suggest that houseplants may serve as a viable means to mitigate stress, depression, anxiety, and loneliness among incoming university students.
Speakers
avatar for Srinivas Reddy Adama

Srinivas Reddy Adama

Graduate Instructional Assistant, Texas State University
Co-authors
TW

Tina Waliczek Cade

Texas State University
Friday September 27, 2024 12:30pm - 12:45pm HST
South Pacific 1

12:30pm HST

VGBR 3 - Identification and Validation of Novel Resistance Loci to Fusarium oxysporum f.sp. lycopersici Race 3 in Tomatoes
Friday September 27, 2024 12:30pm - 12:45pm HST
Fusarium wilt disease caused by the soil-borne pathogen Fusarium oxysporum f. sp. lycopersici (Fol) is a major threat in tomato-producing regions that can lead to acute yield losses. Host resistance as compared to other control strategies provides an effective and reliable means to contain the spread of the pathogen. Given that genes that confer resistance to all the three known Fol races are single dominant genes, there is a risk of resistance breakdown by the mutating pathogen. Furthermore, in the face of imminent race 4 emergence, building a quantitative and durable resistance shield by pyramiding novel resistant genes in commercial cultivars becomes pertinent. S. pennellii has been previously identified as a repository for resistant genes to Fol3 and recently, two novel loci mapped at chromosomes 3 and 10 were identified from two accessions- LA 1522 and LA 750 respectively using bulk segregant analysis QTL seq. Preliminary analysis was conducted to develop molecular markers for both chromosomes and validate their co-segregation with the region of introgression associated with resistance. We found co-segregating markers for resistance harbored by chromosome 3 and designated the locus as I8. This marker therefore constitutes additional genomic resources for marker-assisted selection of this trait. Although we found markers that co-segregate with resistance on chromosome 10, we provide initial evidence that this resistance is the same with the I6 locus previously identified on chromosome 10 and derived from LA 716 while complementary phenotypic screens showed partial penetrance of this locus. Together, these resistance loci (I6 and I8) could constitute a qualitative shield against the pathogen in commercial cultivars. Efforts are underway to fine map these loci and characterize them under field conditions and against other previously known races.
Speakers
avatar for Samuel Ipinyomi

Samuel Ipinyomi

Graduate Research Assistant, University of Florida
NA
Co-authors
GV

Gary Vallad

University of Florida
NA
GM

Geoffrey Meru

University of Florida
NA
JC

Jessica ChitwoodBrown

University of Florida
SH

Samuel Hutton

University of Florida
NA
SL

Seonghee Lee

University of Florida
NA
Friday September 27, 2024 12:30pm - 12:45pm HST
South Pacific 4

12:45pm HST

CE 8 - Greenhouse supplemental lighting of lettuce and tomatoes to a target light intensity and daily light integral using dimmable LEDs
Friday September 27, 2024 12:45pm - 1:00pm HST
A previously developed algorithm controls on/off decisions for greenhouse supplemental light fixtures and retractable shade curtains to achieve a target daily light integral (DLI). The algorithm, termed LASSI (Light and Shade System Implementation) originally used high pressure sodium (HPS) lights with a 1-hour time step to avoid the warm-up time and reduced lifespan of HPS bulbs when they are frequently turned on/off. We have updated the algorithm accounting for dimmability of light emitting diodes (LEDs) for which light intensity can be adjusted in near real-time (RT LASSI). The objective of this study was to compare performance of lettuce ‘Rex’ and Rouxai’ and tomato ‘Sweetelle’ in response to the LASSI algorithm with HPS fixtures vs. RT LASSI with dimmable white LEDs. Experiments were conducted in adjacent greenhouses and DLI setpoints were 17 mol·m-2·d-1 for lettuce and 25 mol·m-2·d-1 for tomatoes. RT LASSI greenhouses had white LEDs (TSR Grow TG-600 HVR) and LASSI greenhouses had HPS fixtures (PL Light 1000 W). For treatments with RT LASSI, when supplemental lighting was called for, LED treatments were adjusted to complement sunlight to achieve a target instantaneous light intensity of 300 and 400 µmol·m-2·d-1 for lettuce and tomatoes, respective, averaged over a 10 minute interval. For tomatoes a minimum 4-hour dark period was imposed while for lettuce, supplemental lighting could occur anytime within the 24-hr period. For lettuce there were three replicate, 35 d crop cycles and for tomatoes plants received 15 weeks of treatment after reaching the fruiting stage with no replication. Both algorithms controlled DLI close to target. For lettuce, LASSI with HPS led to larger plant height and volume and increased fresh weight (but not dry weight) vs. RT LASSI with LED. For tomatoes, RT-LASSI with LED led to about a 30% greater tomato yield vs. LASSI with HPS. Increased yield was associated with increased fruit size but not increased fruit or truss number. Brix of HPS grown fruit was higher than LED fruit. While air temperature was very similar between both treatments, HPS fixtures may have increased plant temperature of LED. More research is needed to determine if plant impacts were due to type of lighting fixture and associated plant temperature and light spectrum or to the control algorithm itself (spreading supplemental lighting across greater hours per day).
Co-authors
NK

Nicholas Kaczmar

Cornell University
NA
TS

Timothy Shelford

Cornell University
NA
Friday September 27, 2024 12:45pm - 1:00pm HST
Nautilus

12:45pm HST

CHEX 2 - Will Consumers Purchase a Landscape Scouting Program?
Friday September 27, 2024 12:45pm - 1:00pm HST
The US landscape industry comprises 632,000 businesses with >1 million employees in 2022. The most common service landscape service providers (LSPs) perform is pest management. Over the past 25 years, consumers have increasingly requested that LSPs use more holistic approaches to pest management, including nonchemical and less toxic chemical control methods. Integrated pest management (IPM), specifically scouting, may be useful for LSPs to manage pests more sustainably and market new services, such as biological control releases. Little published literature details LSP scouting practices or consumer acceptance of scouting services. The goal of this study was to determine if IPM-aware consumers were more likely to purchase a scouting program offered by a LSP. A third-party panel service distributed an online survey across the United States. The final sample included 928 usable responses. Data were analyzed using a binary logistic regression model. Fifty-seven percent of respondents reported having some knowledge or that they were very knowledgeable of IPM. Increased consumer knowledge of IPM increased purchase likelihood. Respondents who self-reported “some knowledge” (5.6%) and “very knowledgeable” (8.6%) of IPM were more likely to buy scouting services. Respondents 65 years of age and older were 13.1% less likely to purchase a scouting service, regardless of IPM knowledge level. Consumers open to purchasing a scouting program, may also be more willing to allow a LSP to use a combination of chemical and nonchemical methods to manage pests. Further research is needed to determine consumer willingness to pay for scouting programs as well as non-chemical treatment options offered by LSP.
Speakers
AJ

Andrew Jeffers

Clemson University
I am a native of the mountains of eastern Tennessee. I have a B.S. in Agriculture – Plant and Soil Science, and M.S. in Plant and Soil Science from the University of Tennessee. My thesis project focused on woody tree and shrub liner production. I have worked as an herbaceous... Read More →
Co-authors
BB

Bridget Behe

Michigan State University
NA
MV

Michael Vassalos

Clemson University
NA
SW

Sarah White

Clemson University
NA
WB

William Bridges

Clemson University
NA
Friday September 27, 2024 12:45pm - 1:00pm HST
South Pacific 2

12:45pm HST

GG 4 - Safeguarding Herbaceous Ornamental Plant Diversity: The Ornamental Plant Germplasm Center
Friday September 27, 2024 12:45pm - 1:00pm HST
Ornamental crops play an indispensable role in enriching our daily lives, offering not just visual delight but also therapeutic benefits. Moreover, the floriculture industry stands as a pivotal pillar within the nation’s agriculture sector, experiencing a substantial 16% increase in sales from 2019-2022, marking it as one of the fastest-growing industries. Safeguarding ornamental plant diversity has become more crucial than ever to sustain this industry and ensure its continued growth and resilience in the face of climate changes and evolving consumer preferences. Located in Columbus, OH, the Ornamental Plant Germplasm Center (OPGC) is one of 20 gene banks in the U.S. National Plant Germplasm System. Established through a cooperative effort between the USDA-ARS and The Ohio State University, it began operations in 2001. The center’s main goals are to acquire, document, maintain, characterize, and distribute herbaceous ornamental genetic resources and associated information for conservation, and to enhance scientific research as well as the floriculture and nursery industry. Current priority genera include Begonia, Coreopsis, Lilium, Phlox, Rudbeckia, and Viola. Since the OPGC began operation, 7350 accessions have been acquired, representing significant diversity within the 432 genera and over 2000 species of herbaceous ornamentals conserved. More than 13,000 germplasm items have been delivered free of charge to researchers, breeders and educators around the world. This presentation will outline the core functions of OPGC, including its germplasm collection, conservation techniques, and collaborative research initiatives.
Speakers
YM

Yu Ma

Ohio State University
Co-authors
SS

Susan Stieve

The Ohio State University
NA
Friday September 27, 2024 12:45pm - 1:00pm HST
Coral 1

12:45pm HST

HIH - Evaluating the Needs and Barriers of Commercial Fruit and Vegetable Growers in Southwest Puerto Rico: A Qualitative Approach
Friday September 27, 2024 12:45pm - 1:00pm HST
According to the 2017 Census of Agriculture, the gross value of sales of fruits and vegetables produced in Puerto Rico totaled $52,127,495. Over 60% of these sales were generated in the island’s two main fruit and vegetable-producing regions, namely $25,351,987 in Region 4-Ponce and $7,948,690 in Region 8-San Germán (Census of Agriculture, 2017). This study examined the needs, barriers, and sources of information used by farmers in those regions. We employed a multiple-case research design and conducted in-depth interviews with 15 growers with diverse backgrounds and experiences (e.g., members of agricultural cooperatives, beginning farmers with four years of operation, smallholder farmers with less than 10 acres, farmers with large operations exceeding 250 acres, women-led farms, and farms with different production systems, such as conventional, certified organic, and agroecology). The Theory of Planned Behavior informed the interview protocol to capture attitudes, social norms, and perceived behavioral control affecting farmers’ intentions to continue producing fruit and vegetables in the short and long term. This study was approved by the Institutional Review Board (UF-IRB: 202102464/ UPRM-IRB: 2023010008), and informed consent was obtained from all participants. The interviews were transcribed and analyzed using Thematic Analysis. Our preliminary results indicate that the main barriers include issues related to (i) climate variability, (ii) labor, and (iii) market pricing and commercialization. Growers particularly emphasized experiencing crop damage, yield reductions, and sales losses due to climate shocks such as erratic weather patterns, drought, extreme heat, and an increase in the prevalence and severity of insect pests. Concerning labor, growers reported challenges in recruiting and retaining qualified and skilled workers, citing the high cost and administrative burden associated with the H-2A temporary agricultural workers program. Farmers, regardless of scale or production system, expressed difficulties due to recurrent oversupply of similar crops in the market, leading to the acceptance of lower prices. Additionally, growers highlighted issues related to the reliability, efficiency, and lack of distribution channels. Regarding sustainability in their production systems, most participants expressed a need for more information and dissemination of sustainable pest management practices. Notably, farmers’ most frequently utilized sources of information included videos, technical bulletins, and blogs available on the web. Our findings offer valuable insights for designing future outreach programs, developing research priorities, and formulating funding initiatives, with a specific focus on enhancing fruit and vegetable production systems in Puerto Rico.
Speakers
AL

Angela Linares Ramirez

Professor, University of Puerto Rico
Friday September 27, 2024 12:45pm - 1:00pm HST
South Pacific 1

12:45pm HST

VGBR 3 - Enhancing Fusarium Wilt Race 2-Resistance and Brix Content in Watermelon through Genomic Selection
Friday September 27, 2024 12:45pm - 1:00pm HST
Complex traits in plants are influenced by many genes, each having a small impact. Using marker-assisted selection (MAS) alone is not sufficient to improve these traits in elite cultivars. Genomic selection (GS) is a promising breeding approach for enhancing complex traits like resistance to Fusarium oxysporum f. sp. niveum (Fon) race 2 and increasing sugar levels (brix content) in watermelon. In our study, we wanted to see how well GS can predict disease resistance and sugar levels in an interspecific citron melon (Citrullus amarus) by cultivated watermelon (Citrullus lanatus) population. We created an F2:3 population by crossing USVL252-FR2 (resistant to Fon race 2, low brix; C. amarus) with ‘Sugar Baby’ (susceptible to Fon race 2, high brix; C. lanatus). We tested disease resistance in a growth chamber and measured sugar levels in a field trial using a randomized complete block design of the F3 families. We resequenced the DNA of 150 F2 plants to identify genetic differences. Disease response was assessed 28 days after inoculation, and sugar levels were measured with a brix meter to gauge sweetness. To predict disease resistance, we used two genomic models - Random Forest and GBLUP - which we found to be effective in previous studies. We compared the performance of univariate models (looking at disease and sugar levels separately) and bivariate models (looking at disease and sugar levels together) to identify the best approach for selecting superior cultivars based on these traits. We assessed model performance using ten-fold cross-validation. Our goal is to focus on these important polygenic traits and select superior genotypes early in breeding to develop watermelon cultivars with improved disease resistance and high sugar content.
Speakers
AB

Anju Biswas

USDA-ARS
NA
Co-authors
AL

Amnon Levi

USDA-ARS
NA
HH

Hannah Houston

USDA-ARS
NA
PW

Patrick Wechter

Clemson University
NA
SB

Sandra Branham

Clemson University
NA
Friday September 27, 2024 12:45pm - 1:00pm HST
South Pacific 4

1:00pm HST

CE 8 - Hybrid Model for Forecasting Lettuce Yield in Indoor Vertical Farming
Friday September 27, 2024 1:00pm - 1:15pm HST
The surging demand for sustainable agriculture has accelerated the adoption of indoor vertical farming as a pragmatic solution. Lettuce, a cornerstone crop in this context, assumes significant importance. Accurate forecasting of lettuce yield is indispensable for optimizing resource allocation and ensuring a steady supply. Most existing models used either environmental data or images to predict yield predictions, which could be erroneous for complex systems. This study aims to improve the accuracy of yield prediction in indoor farming settings with a hybrid model. First, we applied the feedforward neural network and random forest models for yield prediction, leveraging data from environmental sensors, cultivation practices, and historical yield records. Then, a convolutional neural network model is tailored to forecast yield using image data captured by RGBD cameras. Based on our results, we found reasonable accuracy in terms of RMSE and MAE, which range between 10-25 gm and 28-49 g, respectively. By amalgamating these diverse models, we aim to elevate yield prediction accuracy. It’s hypothesized that the proposed hybrid model would outperform individual approaches, offering invaluable insights for indoor vertical farming operations decision-making.
Speakers
MS

MD SHAMIM AHAMED

University of California, Davis
Friday September 27, 2024 1:00pm - 1:15pm HST
Nautilus

1:00pm HST

CHEX 2 - Native Plant Extension Programming for Commercial Horticulture Professionals
Friday September 27, 2024 1:00pm - 1:15pm HST
Native plants are becoming increasingly popular choices for low-input ornamental landscapes in residential and commercial applications. Many nurseries and landscape professionals are currently growing or offering at least some native plants in response to this increasing demand. However, supplies are still limited and there are specific best management practices associated with growing, marketing, and maintaining native plants that need further development. In response to this need from the green industry, replicable, applied programming focused on supporting growers who are currently producing or have an interest in producing native plants was developed. To first prioritize the needs of the industry, a state-wide native plant needs assessment survey was developed and disseminated to nursery and landscape professionals. The survey received 60 responses and indicated that native alternatives to invasive species, deer resistant native plants, and new cultivars of native plants were among the top priorities, in addition to IPM practices, stress tolerance, and propagation protocols. Based on this direction from stakeholders, extension programming was developed to meet these needs and support the green industry in their production and marketing of native plants. Educational programs focused on commercial native plant production and management were developed and delivered both in-person and virtually through webinars, while twilight meetings, including sessions at established native plant nurseries, facilitated grower-to-grower learning and interaction. Program evaluation surveys indicated strong metrics for knowledge gain, incorporating more native plants in their operations, reducing inputs, and achieving better pest control measures. Field trials comparing cultivars of deer-resistant native ornamental grasses offered growers and landscapers a chance to observe how these plants performed throughout three growing seasons, while offering a low-input alternative to non-native species in the landscape. Propagation trials were conducted to begin optimizing protocols for both vegetative cuttings and seed propagation of locally collected native ornamental plants, with success rates documented for each species using standard propagation protocols. A video was also created and shared with stakeholders showcasing a virtual tour of a commercial golf resort that has successfully incorporated native plants into their landscape, thus serving as an example for how to achieve an ornamental landscape aesthetic using native species. While native plant species may vary among ecoregions, this comprehensive approach is replicable and has been met with a high degree of satisfaction from commercial horticulture professionals.
Speakers
WE

William Errickson

Rutgers University
Co-authors
MB

Michele Bakacs

Rutgers University
NA
TW

Timothy Waller

Rutgers University
Timothy J Waller, Ph.D. is serving in his fourth year as the Commercial Nursery Agent of Rutgers Cooperative Extension in southern NJ, based out of Cumberland County. Tim has a Ph.D. in Plant Biology with a focus on fungal plant pathology and has been a licensed pesticide applicator... Read More →
Friday September 27, 2024 1:00pm - 1:15pm HST
South Pacific 2

1:00pm HST

GG 4 - SNP-Enabled Genetic Diversity and Population Structure of Gladiolus (Gladiolus ×hybridus) Cultivars
Friday September 27, 2024 1:00pm - 1:15pm HST
Studies on genetic diversity and population structure provide important insights for determining ancestry and target trait enhancement in breeding programs. Gladiolus(-i), Gladiolus ×hybridus (Iridaceae), is a tetraploid, asexually-propagated, herbaceous perennial floricultural crop. Gladioli have tall flower stalks which make them ideally suited for cut flowers (floral design) and annual garden plants. Gladiolus is an important cut flower crop (in the top 5) for floral design. The purpose of this study was to analyze the genetic diversity of cultivated gladiolus germplasm to determine ancestry and relatedness. In this study we examine 549 unique gladiolus cultivars using DNA marker-based analysis. Samples were collected from the public (University of Minnesota) and private (Meyer, Otto) sector breeding programs in Minnesota and Europe. Population genetic diversity was analyzed using 17,556 single nucleotide polymorphism (SNP) markers developed by low-density DArTseq technology. Despite phenotypic differences, primarily in flower color or type (ruffled, etc.), the genetic diversity of gladiolus cultivars is low. The heterozygosity value was Ho=0.09 and the Fischers (FHOM) inbreeding coefficient was FHOM=0.40. SplitsTrees showed no differentiation, the average minor allele frequency (MAF) and polymorphism information content (PIC) was MAF=0.12 and PIC=0.15. The lack of significant genetic diversity among cultivars as well as breeding programs demonstrates a narrow germplasm base for this important cut flower crop. We discuss our findings and recommend ways to use these conclusions to improve future genome-wide association studies (GWAS) as well as increase efficiency and diversity in breeding goals.
Speakers
MA

Marie Abbey

University of Minnesota
Marie Abbey is a researcher at the University of Minnesota Horticultural Science department. She has studied perceptions of biotechnology, invasive plant species, and aquaponics. Her current research is in flower breeding and molecular genetics.
Co-authors
NO

Neil O Anderson

University of Minnesota
NA
RE

Rajmund Eperjesi

University of Minnesota
NA
Friday September 27, 2024 1:00pm - 1:15pm HST
Coral 1

1:00pm HST

HIH - Soilborne Disease, Plant-parasitic Nematode, Insect Pest, and Weed Challenges Faced by High Tunnel Growers and Preferred Strategies to Overcome Those Challenges: Preliminary Results from a Kentucky Farmer Survey
Friday September 27, 2024 1:00pm - 1:15pm HST
Small farms in Kentucky use high tunnels (HTs) to help increase farm profitability and resilience and give them the ability to extend their growing season for year-round production of high-value specialty crops. Although HTs are semi-permanent structures, many are never moved due to land constraints, the time and labor required to move them, and because corner posts are often cemented into the ground to secure the structure from weather events. The continuous cropping in non-rotated soil can intensify pathogen, insect pest, and weed population densities. The multiple benefits of HTs may be reduced or disappear when soilborne pest pressure increases. We conducted a survey of Kentucky vegetable growers between January and March 2024 to assess production challenges faced when growing vegetables in high tunnels, specifically those related to soilborne diseases, plant-parasitic nematodes, insect pests, and weeds, and the preferred strategies to manage those challenges. We had a particular interest in assessing farmers' use or willingness to use soil solarization as a strategy to manage these issues in high tunnels. Farmers were surveyed using both web-based and mail versions of the survey. We targeted producers growing high-valued crops in their high tunnels, specifically tomato, lettuce, and leafy greens. Preliminary results suggest that common soilborne diseases faced by survey respondents include Sclerotinia spp. A large percentage of respondents indicated they have not had or they do not know if they have soilborne diseases or plant-parasitic nematodes. Regarding insect pests, the most common pests faced by survey respondents are aphids and whiteflies. Finally, common weed problems faced by survey respondents include pigweed, crabgrass, and chickweed. Common strategies used by respondents to address these problems include fungicides, insecticides, and hand weeding. Regarding soil solarization, only a small percentage of respondents are using or have used soil solarization. Nonetheless, more than 75% of those respondents who are not using or have not used soil solarization are willing to use soil solarization. The two most important reasons for wanting to use soil solarization include interest in using more environmentally friendly practices and the belief that soil solarization might be cheaper and more effective in managing weeds, insect pests, diseases and /or plant-parasitic nematodes in high tunnels.
Speakers
MV

Margarita Velandia

The University of Tennessee
NA
Co-authors
AW

Annette Wszelaki

The University of Tennessee
NA
RR

Rachel Rudolph

University of Kentucky
NA
SS

Susan Schexnayder

The University of Tennessee
NA
Friday September 27, 2024 1:00pm - 1:15pm HST
South Pacific 1

1:00pm HST

VGBR 3 - Introgressing QTL from a Wild Relative to Improve Gummy Stem Blight Resistance in Watermelon
Friday September 27, 2024 1:00pm - 1:15pm HST
Watermelon (Citrullus lanatus) is an economically important horticultural crop known for its sweet red flesh and is a popular summer snack. The southeastern US is an important production region for watermelon, but the hot and humid weather is conducive for the development of fungal diseases. Gummy stem blight (GSB), caused by three species of Stagonosporopsis; S. citrulli, S. caricae and S. cucurbitacearum, is an important disease that can cause severe yield losses worldwide under these favorable conditions. Currently, no resistant cultivars are available for this disease and management depends on preventative fungicide spay programs. Host resistance has been previously identified in C. amarus, an inedible crop wild relative of watermelon. However, different Stagonosporopsis spp. isolates elicit different responses in different resistant host genotypes which complicated resistance breeding. To address these issues, we (i) developed a point-of-care assay that can differentiate S. citrulli from the other two species and (ii) introgressed resistance QTL from wild C. amarus into cultivated watermelon. A dipstick-based DNA extraction method was coupled with an S. citrulli specific loop-mediated isothermal amplification (LAMP) assay to detect as little as 1 pg of DNA with real time fluorescence quantification and endpoint colorimetric detection formats. To address host resistance, we developed high throughput KASP markers spanning the QTL regions, and used marker assisted backcrossing to introgress QTL into the cultivar Crimson Sweet. Eight BC2F3 intogression lines were evaluated in the field for resistance to GSB. Two of the lines showed high levels of resistance to GSB under field conditions. KASP assays were also developed for background selection for known domestication alleles to accelerate selection for fruit quality traits. The developed detection assays, KASP markers and introgression lines can contribute to accelerated breeding for host resistance and general breeding efforts for GSB in watermelon.
Speakers
CM

Cecilia McGregor

University of Georgia
NA
Co-authors
AB

Amelia Boettcher

University of Georgia
NA
JR

Jorge Reyes

University of Georgia
NA
SR

Samikshya Rijal

University of Georgia
NA
Friday September 27, 2024 1:00pm - 1:15pm HST
South Pacific 4

1:15pm HST

CE 8 - Development of a pH Management Protocol for Strawberry Mother Plants Grown in Deep Water Culture
Friday September 27, 2024 1:15pm - 1:30pm HST
Maintaining a target pH range is important for root zone management and overall plant growth and quality. Commercial soilless substrates often contain liming amendments to increase initial substrate pH to between 5.5 and 6.2. Hydroponic nutrient solutions are less-well buffered than soilless substrates and can experience pH drift in the absence of frequent monitoring and adjustment. Hydroponic deep water culture (DWC) was explored for strawberry (Fragaria × ananassa) research studies, to more-easily collect root growth parameters and root samples for elemental analysis, compared to soilless substrate culture. However, an effective strategy for pH management needed to be developed. The objective of this study was to develop a protocol for growing strawberry mother plants hydroponically. First, three hydroponic systems (drip-irrigated coarse perlite, drip-irrigated sand, and DWC) were compared to a peat-based soilless substrate control. Plants received a modified strawberry nutrient solution (Yamazaki) at a nitrogen (N) concentration of 100 mg·L-1. Plants grew similarly across the four growing systems. Deep water culture provided the easiest access to clean roots; however, root zone pH decreased
Speakers
JB

Jennifer Boldt

Research Horticulturist, United States Department of Agriculture
Co-authors
EY

Erin Yafuso

United States Department of Agriculture
Friday September 27, 2024 1:15pm - 1:30pm HST
Nautilus

1:15pm HST

GG 4 - Development of Genetic Fingerprinting of Azalea Cultivars Using SSR Markers
Friday September 27, 2024 1:15pm - 1:30pm HST
Azaleas (Rhododendron spp.) are economically important ornamental flowering shrubs in landscapes around the world with thousands of cultivars representing many species of Rhododendron. Because azalea is an asexually propagated crop, potential discrepancies in plant identity may occur throughout the propagation pipeline, which can lead to mislabeling during propagation and commercialization processes. For example, the University of Minnesota (UMN) cultivar ‘Electric Lights Double Red’ is currently being propagated but flower morphology of the propagules differed from the original plant leading to uncertainty of propagule identity. Previous studies have identified DNA markers, specifically simple sequence repeats (SSRs), capable of differentiating azalea hybrid offspring from different species of the section Pentanthera. This study aims to leverage these previously developed SSR markers to authenticate the identity of breeding germplasm at the UMN and uniquely fingerprint other cultivars on the market. The evaluated azaleas pedigrees include up to 15 different species of deciduous azalea. Therefore, a total of 15 SSR markers that amplified fragments from several species of section Pentanthera were selected for this study. DNA was extracted from lyophilized leaf samples of 139 azalea cultivars using a Qiagen DNeasy Plant Pro Kit. Preliminary analysis of the azalea DNA using the selected SSR markers has identified the presence of 16 expected unique cultivars and 3 pairs of previously known duplicates. The outcome of this research will demonstrate the feasibility of providing azalea breeders, growers, and producers a marker-based system for assuring cultivar trueness-to-type and protection of intellectual property.
Speakers
avatar for Seth Wannemuehler

Seth Wannemuehler

University of Minnesota
Co-authors
DL

Diana Lopez Arias

University of Minnesota
NA
SH

Stan Hokanson

University of Minnesota
NA
SM

Steve McNamara

University of Minnesota
NA
Friday September 27, 2024 1:15pm - 1:30pm HST
Coral 1

1:15pm HST

HIH - Gauging 8th Graders’ Knowledge of Organic Agriculture Production and Labeling Practices
Friday September 27, 2024 1:15pm - 1:30pm HST
Pathways2Possibilities (P2P) is an interactive career expo for 8th graders in Mississippi. P2P encompasses 19 career pathways. The Agriculture, Food and Natural Resources Career Pathway focuses on supporting life by ensuring that we are responsibly managing our food production and natural resources. This pathway focuses on preparing students for careers in planning, implementing, producing, managing, processing and marketing of agricultural goods and services. Gulf Coast P2P hosted nearly 7,000 8th graders from 10 Coastal counties in the fall of 2023. from 10 South Mississippi counties. Delta P2P hosted nearly 2,000 8th graders from 10 Delta counties in the spring of 2024. At each event, a six question survey was presented to the students to determine their knowledge of organic agriculture and labeling practices. Questions were posed as Yes or No and were answered by Red (no) or Blue (yes) tickets in opaque boxes. Students were given temporary fruit and vegetable tattoos for participating. The six questions and respective YES responses (by location GC for Gulf Coast and D for Delta) were as follows: 1) Are genetically modified organisms allowed in organic products? GC: 31%, D: 48%; 2) Are organic farmers allowed to use natural methods for pest control? GC: 92%, D: 65%; 3) Are organic farms typically smaller than conventional farms? GC: 63%, D: 65%; 4) Is organic farming regulated by the U.S. government to ensure organic food labels accurately represent the product’s authenticity? GC: 63%, D: 58%; 5) Are organic products labeled with a special certification to help consumers identify them in stores? GC: 81%, D: 79%; and 6) Do certifies organic products have to be produced on a certified organic farm? GC: 53%, D: 62%. Nearly 600 students participated in the Gulf Coast survey and approximately 400 students participated in the Delta survey. Results are mixed as to how much knowledge students have about organic agriculture production and labeling.
Speakers
avatar for Christine Coker

Christine Coker

Professor or Urban Horticulture, Mississippi State University
Co-authors
BB

Brenton Breland

Mississippi State University
HW

Haley Williams

Mississippi State University
JR

Jenny Ryals

Mississippi State University
ME

Mike Ely

Mississippi State University
NA
PK

Patricia Knight

Mississippi State University
NA
Friday September 27, 2024 1:15pm - 1:30pm HST
South Pacific 1

1:15pm HST

VGBR 3 - Genome-wide association study reveals potential loci for powdery mildew resistance in the USDA core collection of Cucurb
Friday September 27, 2024 1:15pm - 1:30pm HST
Summer squash (Cucurbita pepo) is a significant vegetable crop in the United States with an annual value exceeding $216 million. The production of summer squash is significantly hindered by powdery mildew (PM), a fungal disease caused by Podosphaera xanthii. Management of PM relies on costly and routine application of fungicides. Moderate resistance to PM (designated PM0) in C. okechobeensis is widely deployed in commercial summer squash cultivars. However, it is important to expand the repertoire of alleles against PM in squash to complement and reduce the risk of PM0 resistance breakdown. In the current study, the USDA core collection of C. pepo (n= 207) was evaluated for PM resistance in Florida (greenhouse), New York (greenhouse), and Michigan (field) using a randomized complete block design across three reps, each with five plants. ‘Success PM’ (carrying PM0) and ‘Early Prolific’ Straightneck cultivars were used as resistant and susceptible checks, respectively. Pathogen inoculum was provided through naturally infected plants. At the 6th true-leaf stage, symptom severity data were collected on a scale of 0-100% based on visible pathogen sporulation on the surface of ‘top 4th leaf’, ‘bottom 4th leaf’, ‘stem above 4th leaf’, ‘stem below 4th leaf’, and ‘whole plant’. Across locations, ‘Success PM’ and ‘Early Prolific’ were consistently tolerant and susceptible, respectively. On the other hand, wide phenotypic variation was observed across the C. pepo core collection with accession 189 showing resistance across locations. The multi-location phenotype data was combined with genome-resequencing data (4 million SNPs) for the core collection to conduct a genome-wide association study using three statistical models (MLM, FarmCPU, and Blink). GWAS analysis for the FL dataset revealed significant genomic loci associated with PM resistance for ‘top 4th leaf’ (Chr 11 and 20), ‘stem above 4th leaf’ (Chr 4, 14 and 16), and ‘whole plant’ (Chr 13, 15, 18 and 20). Resistance loci for ‘top 4th leaf’ and ‘whole plant’ co-located on Chr 20, suggesting potential linkage/ pleiotropy for the two traits. For NY, significant hits for PM resistance were detected for the ‘top 4th leaf’ (FarmCPU: Chr 2, 4, 7, 13 and 19; Blink: Chr 3, 4, 5 and 19) and ‘bottom 4th leaf’ (Chr 6, 14 and 19). However, no significant GWAS hits were observed using MI data. The significant loci detected in this study will be validated and deployed in marker-assisted selection to improve PM resistance in squash.
Speakers
PS

Prerna Sabharwal

PhD Student, University of Florida
NA
Co-authors
CM

Carmen Medina-Mora

Michigan State Univ.
NA
CT

Charles Thomas Day

Cornell University
NA
CD

Christine D Smart

Cornell University
NA
GM

Geoffrey Meru

University of Florida
NA
GP

Gregory P Inzinna

Cornell University
NA
LI

Libby Indermaur

Cornell University
NA
MH

Mary Hausbeck

Michigan State University
NA
MM

Michael Mazourek

Cornell University
NA
Friday September 27, 2024 1:15pm - 1:30pm HST
South Pacific 4

1:30pm HST

CE 8 - Adjusting dissolved oxygen in nutrient solution for optimized kale and arugula growth in hydroponics
Friday September 27, 2024 1:30pm - 1:45pm HST
Dissolved oxygen (DO) level in hydroponic solution is an important factor affecting plant root development and water and nutrient uptake. However, precisely controlling the DO level in hydroponics has always been difficult due to the direct linkage of solution temperature and oxygen concentrations, especially under different aeration methods. Besides potentially controlling solution temperature, using liquid oxygen fertilization such as hydrogen peroxide (H2O2) has been shown to burst increase DO concentration in the solution, and ozonation, which is a sanitization treatment, has the potential to adjust DO level by supplying oxygen in nutrient solution. Our objective was to evaluate the effects of different DO levels and oxygenation strategies in a hydroponic system for the optimal growth of kale (Brassica oleracea) and arugula (Eruca vesicaria). In this study, we used ozone generators and hydrogen peroxide (H2O2) as a DO enrichment method in addition to the air pump-based aeration system to test the effects of different DO levels – low, medium, high as 6, 9, 12 mg/L, respectively – on kale ‘KX-1’ and ‘Red Russian’, and arugula ‘Astro’ and ‘Esmee’ grown in a deep water culture system. Treatment without using ozone generators or H2O2 was assigned as control. The study was arranged as a completely randomized design with three replications. DO and temperature probes were connected to a datalogger to trigger ozone generators and H2O2 injection using a relay once the DO levels were below the set thresholds. Weekly measurements were taken for plant height, leaf and anthocyanin chlorophyll content. The final harvest additionally measured leaf area, shoot and root biomass the leaf soluble solids content, titratable acidity, and leaf nutrient concentration. Plants grown under a high DO level had a higher root-to-shoot ratio, but the overall higher plant yield was achieved under the medium DO level. This system demonstrated that precise DO level control could be achieved using a sensor-based system.
Speakers
KQ

Kuan Qin

University of Georgia
Friday September 27, 2024 1:30pm - 1:45pm HST
Nautilus

1:30pm HST

GG 4 - A Chromosome-Scale Haplotype-Resolved Reference Genome of Lantana camara and Insights into Unreduced Female Gamete Production
Friday September 27, 2024 1:30pm - 1:45pm HST
This comprehensive study unveils the first annotated, haplotype-resolved, chromosome-scale reference genome of Lantana camara, alongside insights into candidate genes for unreduced female gamete production through ovary transcriptome sequencing. L. camara, a native of the Caribbean, plays a dual role as a valued ornamental plant and a challenging invasive species. The absence of a high-quality genomic resource has previously limited the exploration of its ornamental and invasive characteristics. This work closes this gap by delivering a critical genomic resource for L. camara, essential for ornamental breeding programs and invasive species management. The genome of a diploid L. camara breeding line UF-T48 was assembled de novo, utilizing HiFi and Hi-C reads, achieving phased genome assemblies with a BUSCO score of 97.7% and LAI score of 19.37, indicating high quality. This assembly resolved all 22 chromosomes into pseudochromosomes, with an average length of 117 Mb, and annotated 83,775 protein-coding genes, laying a foundational step for Verbenaceae family genomic research. Simultaneously, this research delves into the plant’s reproductive biology, specifically targeting the mechanism of unreduced female gamete production, a trait that has played an important role in the evolution and spread of lantana, contributed to the plant’s invasiveness, and and complicated the development of sterile triploids. By aligning RNA-seq data to the reference genome, we identified differentially expressed genes associated with cell division and meiosis, crucial for understanding the genetic underpinnings of unreduced gamete production. These findings not only enhance the genetic comprehension of L. camara but also provide invaluable genomic resources for future genetic studies, conservation efforts, and breeding strategies aimed at producing non-invasive sterile cultivars. This pioneering genomic and transcriptomic analysis marks a significant leap forward in researchers’ ability to manipulate L. camara for both horticultural innovation and environmental management.
Speakers
BP

Brooks Parrish

University of Florida
Co-authors
ZD

Zhanao Deng

University of Florida
Friday September 27, 2024 1:30pm - 1:45pm HST
Coral 1

1:30pm HST

HIH - Growing Impact: Evaluating Global Investments in Fruit and Vegetable Production for Healthier Diets
Friday September 27, 2024 1:30pm - 1:45pm HST
Objective: The Horticulture Investment Study seeks to quantify and qualify public and private investments, alongside identifying challenges and opportunities in horticultural research and development, aimed at facilitating high-level policy engagement. This research is led by the Feed the Future Innovation Lab for Horticulture, in collaboration with the World Vegetable Center, the One CGIAR Initiative on Fruit and Vegetables for Sustainable Healthy Diets (FRESH), and various university partners. Background: Despite widespread recommendations to increase fruit and vegetable consumption—endorsed by 93% of Food-Based Dietary Guidelines—significant barriers remain. These include limited access, high costs, and entrenched dietary preferences, alongside inadequate global production that disproportionately impacts low-income and Global South populations. Addressing these issues is vital for enhancing nutrition and income, particularly through the empowerment of small-scale farmers in the Global South, where fruits and vegetables often represent women-managed crops. Methods: This study spans several countries including Cambodia, Philippines, Nepal, Sri Lanka, Benin, Ghana, Tanzania, Kenya, Guatemala, USA, and Germany. It employs a mixed-methods approach, beginning with a Delphi questionnaire distributed among key stakeholders from government, academia, international NGOs, and the private sector. Subsequent in-person workshops facilitate discussions on investment estimates and the dynamics of horticultural investments in each country. The inaugural workshop in Nairobi, Kenya, gathered 18 local experts who provided critical investment insights and validated the use of Delphi and Q methodologies for this study. Impact: The study aims to illuminate the economic and social impacts of investing in fruit and vegetable production, focusing on enhancing accessibility and affordability. It also addresses environmental considerations such as land use, aiming to support sustainable agricultural practices. By bridging gaps in horticultural investment, the study intends to foster supportive environments that enhance fruit and vegetable production and consumption, thus contributing to the Sustainable Development Goals. Conclusion: This study underscores the critical need for enhanced investment in horticulture to overcome systemic barriers to fruit and vegetable consumption, thereby improving global health and economic outcomes, especially for vulnerable populations in the Global South. The outcomes are expected to guide policy decisions and stimulate further research and development in the horticulture sector.
Speakers
EM

Erin McGuire

Director, University of California, Davis
Friday September 27, 2024 1:30pm - 1:45pm HST
South Pacific 1

1:30pm HST

VGBR 3 - BreedwithBIMS (Breeding Information Management System) for Crop Breeders
Friday September 27, 2024 1:30pm - 1:45pm HST
With the continuous development of new scientific technology and methodology, breeding programs are both producing and utilizing a large amount of big data. This requires efficient management systems to keep track of various types of data such as performance, pedigree, geographical and image-based data as well as genotype data. Access to integrated breeding data in a database enhances genetic understanding of important traits and maximizes the marker-assisted breeding utility by breeders. The Breeding Information Management System (BIMS) is a free, open-source, secure and online breeding management system which allows breeders to store, manage, archive, and analyze their private breeding program data that has been available in several crop databases. But what about the crops that do not have a database? We report the utility of a new BIMS website (www.breedwithbims.org) that allows any crop breeders can use BIMS. One of the key features of BIMS is that users can import new trait data via an Android App called Field Book as well as historical data via templates. Field Book app allows breeders to collect phenotype data with less possibility of transcription errors. BIMS is also BrAPI compliant so that breeders can send and receive data from other BrAPI compliant resources including the Field Book App. Potential for streamlining data collection and management for vegetable crops will be presented.
Speakers
avatar for Ksenija Gasic

Ksenija Gasic

Clemson University
Co-authors
CH

Chun Huai Cheng

Washington State University
NA
DM

Dorrie Main

Washington State University
JY

Jing Yu

Washington State University
NA
JH

Jodi Humann

Washington State University
MI

MIchael Itam

Clemson University
SJ

Sook Jung

Washington State University
NA
TL

Taein Lee

Washington State University
NA
Friday September 27, 2024 1:30pm - 1:45pm HST
South Pacific 4

1:45pm HST

CE 8 - Developing Cardinal Temperatures for Leafy Green Growth and Development Parameters from Constant and Positive Day-Night Temperatures
Friday September 27, 2024 1:45pm - 2:00pm HST
In the evolving landscape of controlled environment agriculture (CEA), precise temperature management remains a pivotal factor in enhancing the growth, development, productivity, and quality of high-value leafy greens. Our research identifies the cardinal temperatures — base (Tb), optimum (Topt), and maximum (Tmax) — for red-leaf and green butterhead lettuce (Lactuca sativa), arugula (Eruca sativa), and kale (Brassica oleracea), comparing how both constant mean daily temperature (MDT) within a greenhouse and positive day-night temperature differences (DIF) in a growth chamber influence plant growth and development. In the greenhouse, we had a constant MDT of 8, 13, 18, 23, 28, and 33 °C under a photosynthetic photon flux density (PPFD) of 220 µmol∙m‒2∙s‒1 for 12 h∙d–1, while in the growth chamber we targeted the same MDTs with air day/night (12 h/12 h) set points of 11/5 °C, 16/10 °C, 21/15 °C, 26/20 °C, 31/25 °C, or 36/30 °C under a PPFD of 300 µmol∙m‒2∙s‒1. Both arugula and kale had greater biomass accumulation at lower Tb and Topt compared to lettuce, suggesting a propensity for growth under a cooler MDT. Specifically, the Topt for fresh mass accumulation was found to be at 24.7 °C for arugula, 22.9 °C for kale, and higher for lettuce cultivars 'Rex' and 'Rouxaï RZ' at 24.7 and 26.2 °C, respectively. We found that DIF exerted minimal influence on these crops, emphasizing the critical role of MDT in influencing their developmental outcomes. Additionally, our research provides insight into the impact of temperature on various physiological and morphological parameters, such as leaf unfolding rate, biomass accumulation, and susceptibility to physiological disorders such as bolting or tipburn. This study underscores the importance of precise temperature management in CEA, offering guidance for producers seeking to optimize energy use while maximizing crop yield and quality.
Speakers
ST

SEAN TARR

Michigan State University
Co-authors
RL

Roberto Lopez

Michigan State University
NA
Friday September 27, 2024 1:45pm - 2:00pm HST
Nautilus

1:45pm HST

GG 4 - Identification of Flowering Dogwood QTLs for Bract Color using a Pseudo-F2 Population
Friday September 27, 2024 1:45pm - 2:00pm HST
Flowering dogwoods (Cornus florida L.), known for their showy spring display and year-round appeal, are extensively planted as ornamental trees. In 2019, dogwoods ranked third in value for deciduous flowering trees in the U.S., generating more than $31 million in wholesale and retail sales. Tennessee is vital to this industry. The state leads the country in the number of dogwood plants sold, with almost double the number of trees sold as the next top producing state in the country. The showy bracts of dogwoods are modified leaves with a spectrum of color ranging from white to red, with many intermediate colors and patterns. Cornus florida ‘Cherokee Brave’ with deep pink bracts and ‘Appalachian Spring’ with creamy white bracts are two popular cultivars. Partially phased reference genomes have recently been assembled and annotated for these cultivars, ranging from 1,253 to 1,266 Mbp in length with 28,558 to 28,768 annotated protein coding genes. With these newly annotated genomes providing greater context, a QTL analysis was conducted using a pseudo-F2 population of ‘Cherokee Brave’ × ‘Appalachian Spring’ which segregates for bract color. Genotyping was completed using double-digest restriction-site associated DNA sequencing (ddRADseq) with PstI and MspI. With increasing demand for high-throughput phenotyping, six different phenotypic methods were utilized to determine which method was optimal for QTL detection. The phenotyping methods included: 1) manual characterization into binary classes (white or pink); 2) manual characterization into five classes (white, light blush, medium blush, pink, red); 3) colorimeter readings; 4) image analysis using full inflorescence; 5) image analysis using bracts detached from inflorescence; and 6) one bract per inflorescence. QTLs were identified using all phenotyping methods. The QTLs identified here will be used as the foundation for developing a marker assisted selection system for bract color in flowering dogwoods.
Speakers
TH

Trinity Hamm

University of Tennessee, Knoxville
Co-authors
DH

Denita Hadziabdic

University of Tennessee, Knoxville
NA
DS

DeWayne Shoemaker

University of Tennessee - Knoxville
NA
MN

Marcin Nowicki

University of Tennessee, Knoxville
NA
MS

Margaret Staton

University of Tennessee, Knoxville
NA
RT

Robert Trigiano

University of Tennessee, Knoxville
NA
SB

Sarah Boggess

University of Tennessee, Knoxville
NA
WK

William Klingeman

University of Tennessee, Knoxville
NA
Friday September 27, 2024 1:45pm - 2:00pm HST
Coral 1

2:00pm HST

FRBR 2 - Introduction of modern tools to the University of Arkansas System Division of Agriculture Fruit Breeding Program
Friday September 27, 2024 2:00pm - 2:15pm HST
The University of Arkansas System Division of Agriculture (UADA) has a legacy breeding program that has spanned three fruit breeders and 60 years. The UADA Fruit Breeding Program is large, complex, and works on multiple crops. A recent program initiative has been the introduction of modern tools for breeding approaches and data collection and management. This talk will outline the process for developing a molecular breeding pipeline for blackberry (Rubus subgenus Rubus Watson) and muscadine grape (Muscadinia rotundifolia) and outline how these approaches benefit program progress. Additionally, advances in data collection techniques such as digital evaluations using an application and development of barcoding systems for streamlining processes and minimizing error will be described.
Speakers
avatar for Carmen Johns

Carmen Johns

Assistant Fruit Breeder, University of Arkansas
I am interested in plant breeding and genetics. My training is in polyploid perennial fruit breeding. I work in the University of Arkansas Fruit Breeding Program as the Assistant Fruit Breeder. We actively work on blackberry, peach, muscadine, and table/wine grape breeding. We have... Read More →
Co-authors
Friday September 27, 2024 2:00pm - 2:15pm HST
Kahili

2:00pm HST

GG 4 - Evaluation of Hibiscus cannabinus as an Alternative Fiber Crop for Florida: Identification of Valuable Traits and Germplasm for Cultivar Improvement
Friday September 27, 2024 2:00pm - 2:15pm HST
Hibiscus cannabinus, commonly referred to as Kenaf, is an annual warm-season plant that can thrive in the Southeastern United States. It serves as a vital source of natural fiber with diverse applications, such as biocomposites, paper pulp, textiles, industrial absorbents, animal bedding, and potting medium. A set of 86 accessions of Hibiscus cannabinus, acquired from USDA-GRIN, underwent evaluation in Central Florida for various parameters, including plant height, basal width, stem width 50 cm above the plant base, stalk fresh weight, stem fresh weight, stalk dry weight, leaf dry weight, bast weight, and core weight. Significant variations were observed among accessions for all the measured variables. Notably, stalk dry weight emerged as the key trait of interest, representing the plant portion with desirable fibers for various applications. The top Duncan grouping for stalk dry weight comprised eight accessions: PI 329191 (18-85), PI 639889 (18-157) known as "Whitten," PI 270111 (18-55) known as "G-32," PI 603071 (18-152) known as "Dowling," PI 638930 (18-154) known as "74200 I4," PI 638932 (18-156) known as "Yue 74-3," PI 270106 (18-50) known as "G-14," and PI 468077 (18-137). Out of the 86 USDA-GRIN accessions examined, these eight have been identified as the top-performing choices for field production in Central Florida. Furthermore, these selected accessions are deemed desirable parents for future cultivar improvement endeavors, aiming to develop enhanced cultivars of Hibiscus cannabinus specifically tailored for production in Central Florida.
Speakers
avatar for James Webb

James Webb

University of Florida
Co-authors
CA

Conner Austin

University of Florida
Friday September 27, 2024 2:00pm - 2:15pm HST
Coral 1

2:00pm HST

LOCSY - Edible Weeds for Sustainable Food Systems: Pilot studies with emphasis on purslane
Friday September 27, 2024 2:00pm - 2:15pm HST
An interdisciplinary team at Montana State University (MSU) has initiated a project to evaluate the cultivation, commercialization, processing, and food use of the associated plant agrobiodiversity, or “edible weeds.” The project involves different food system stakeholders and targets underutilized/neglected edible plant species on local farms. In four pilot studies in Montana, conducted in 2023, we emphasized common purslane (Portulaca oleracea) as a model edible weed due to its abundance in local horticultural systems, its relatively limited competition with crops, and rich data on nutritional properties. Annual common purslane exhibits a versatile habitat range, including gardens, crop fields, and orchards. The hermaphroditic plant is self-fertile, flowers from June to September, thrives in well-drained soils, and requires direct sunlight. While considered a weed across the US, purslane is cultivated in diverse countries due to its culinary and medicinal attributes. Stems and leaves are consumed raw and cooked, in salads, sauces, or soups. Purslane also serves as a thickening agent due to mucilaginous properties. The succulent leaves are abundant sources of omega-3 fatty acids. In our first study, we monitored edible weeds on 3 farms in Bozeman, Montana. Purslane exhibited its highest occurrence in emerging carrot crops and on freshly tilled beds. In our second study, we sampled 35 weed species on 7 vegetable farms across Montana. Purslane had a relative abundance of 6.52% and was found in kale, onions, carrots, and bean plots. In our third study, we conducted a sensory test among attendees of the MSU Presidential Luncheon. We presented 3 purslane products: compound herb butter, cornbread muffin, and blueberry compote. 42 attendees responded to an online survey on their overall quality, flavor, and texture. All products were perceived positively with a rate of 7.5 to 7.7 on a Likert-scale from 1 (dislike extremely) to 9 (like extremely). 52% of participants had never thought about eating edible weeds. Finally, for 2 days, a Mexican restaurant in Bozeman, offered 2 traditional dishes, purslane with pork in green salsa and chicken in red salsa. Participants responded to an online and paper survey with a questionnaire similar to the one for the luncheon. Out of 53 validated responses, dishes were assessed with an average of 8.17 (chicken) and 8.53 (pork) on a 1-9 Likert-scale. Over 90% of respondents considered purslane an appropriate vegetable for these dishes. Our findings indicate potential of selectively weeding purslane from vegetable production systems and consumer interest in the vegetable.
Speakers
avatar for Roland Ebel

Roland Ebel

Assistant Professor, Montana State University
Roland Ebel has a Ph.D. in Organic Farming, granted by the University of Natural Resources and Life Sciences, Vienna. His dissertation project on the diversification if organic tomato systems was conducted in Gran Canaria, Spain. From 2008 to 2014, Dr. Ebel was a member of the Agroecology... Read More →
Co-authors
EK

Emma Kubinski

Montana State University
NA
FM

Fabian Menalled

Montana State University
NA
WK

Wan-Yuan Kuo

Montana State University
NA
Friday September 27, 2024 2:00pm - 2:15pm HST
South Pacific 1

2:00pm HST

PNM 3 - Optimizing Nitrogen Fertilization for Evergreen Blueberry (Vaccinium corymbosum interspecific hybrids) in Florida
Friday September 27, 2024 2:00pm - 2:15pm HST
There are multiple ways to grow highbush blueberries (Vaccinium corymbosum interspecific hybrids). In Florida, an evergreen growing system was developed to overcome unpredictable chill hour accumulation. In this system, blueberry bushes retain their leaves throughout the year when fertilized appropriately. Deciduous blueberry farms typically skip fertilization during the fall and winter months. On the other hand, evergreen blueberry farms require winter fertilization to ensure healthy foliage. Therefore, fertilizer recommendations for deciduous blueberry are not applicable to evergreen blueberry. This research aims to optimize nitrogen fertilization for evergreen southern highbush blueberry plants in Florida. ‘Arcadia’ and ‘Sentinel’ southern highbush blueberry plants were grown in a high tunnel in Citra, FL. Plants were fertigated according to commercial practices, except for nitrogen (N). Nitrogen was applied manually as ammonium sulfate at 5 different annual rates (in Kg/ha): 5.6, 83.4, 138.9, 222.3, and 444.6. Plant size, leaf area index, leaf N concentration, fruit yield, and fruit quality were measured during the 2023 and 2024 seasons. Nitrogen fertilization rates affected plant growth during the spring and summer, but not during the fall and winter. Higher N fertilization rates led to higher leaf area index, a proxy for leaf retention. Plants in the lowest N fertilization treatment were not evergreen, as they dropped nearly all their leaves in the winter. Leaf N concentrations of plants in treatments 83.4 Kg/ha or higher were above the reference levels for N deficiency. Linear plateau regressions were used to identify optimum fertilization rates. During the 2023 season, ‘Arcadia’ exhibited a yield plateau, but ‘Sentinel’ did not, suggesting that N fertilization has cultivar-specific effects. All fruit harvested exhibited commercial quality in terms of soluble solids. However, fruit in the lowest fertilization rate was softer and more acidic than fruit in all other treatments. These results suggest that multi-year studies with multiple varieties are necessary to identify N fertilization rates that maximize agricultural productivity while minimizing fertilizer inputs.
Speakers
GN

Gerardo Nunez

University of Florida
Co-authors
LG

Lauren Goldsby

University of Florida
NA
Friday September 27, 2024 2:00pm - 2:15pm HST
Lehua Suite

2:00pm HST

POM 4 - Six -year Performance of Semi-dwarfing Peach Rootstocks From the NC-140 'Cresthaven' Trial in Western Colorado
Friday September 27, 2024 2:00pm - 2:15pm HST
Eight rootstock cultivars were planted in 2017 as part of the NC-140 semi-dwarfing peach [Prunus persica (L.) Batsch] rootstock trial. The eight rootstock cultivars were budded to ‘Cresthaven’ and examined for their potential use in Western Colorado high density production systems. Listed in order of declining vigor the rootstocks included ‘Guardian®’, ‘Rootpac® 20’, ‘Lovell’, ‘ControllerTM 8’, ‘ControllerTM 6’, ‘Rootpac® 40’, ‘ControllerTM 7’, and ‘MP-29’. One rootstock, ‘ControllerTM 7’, was unable to perform in alkaline soils, showing extreme iron chlorosis and diminutive fruit size. Deemed unsuitable for use in Colorado, this rootstock was removed from analysis in the 3rd leaf. Six years of data showed that all remaining rootstocks, except ‘MP-29,’ had vigor profiles within 14% of ‘Lovell’, a known standard, making them attractive candidates for use in high density production. The two ‘Rootpac®’ rootstocks performed contrary to previous reports. ‘Rootpac® 20’ was the second most vigorous and ‘Rootpac® 40’ was the third least vigorous, slightly larger than ‘ControllerTM 6’. Additional physiological traits showing distinct differences between the rootstocks were yield, proleptic shoot formation, light interception, fruit size, and internal fruit quality. In the six years since planting there have been three harvests. Cumulative yield showed a strong linear relationship to vigor (TCSA). ‘ControllerTM 6’ had early precocity and high yields given its vigor class. Observance of gummosis was also positively associated with vigor. Both vigor and proleptic shoot formation manipulated the canopy light environment. ‘ControllerTM’ series rootstocks had increased proleptic shoot formation. Vigor-limiting rootstocks had increased light availability in the canopy leading to enhanced dry matter content and soluble solid concentration. Cumulative fruit size and weight showed ‘Rootpac® 20’ had the heaviest, and ‘ControllerTM 6’ the largest, fruit size. ‘MP-29’, the most dwarfing rootstock produced smaller fruit on average; however, fruit size was still commercially acceptable.
Speakers
JP

Jeff Pieper

Colorado State University
Co-authors
Friday September 27, 2024 2:00pm - 2:15pm HST
South Pacific 3

2:15pm HST

FRBR 2 - A Century of Pear Breeding at the USDA
Friday September 27, 2024 2:15pm - 2:30pm HST
The U.S. Department of Agriculture (USDA) Agriculture Research Service (ARS) has operated a European pear (Pyrus communis) scion breeding program for over a century. The breeding program started in the early 1900s by Merton B. Waite in the Washington D.C. area with the primary objective to develop host resistance to fire blight, a devastating disease caused by Erwinia amylovora. The USDA pear breeding program has continued this effort throughout its history, spanning over six generations of breeders and two cooperative research programs in Michigan and Ohio. The program has released ten named pear varieties, with the first one, 'Waite,' being released in 1938 and the most recent, 'Bell,' in 2022. In this presentation, we discuss the program's history by detailing each generation of breeder(s) aims, their parental selection, and releases. In addition, we present corrected pedigrees for important breeding lines and the releases. Lastly, we present the current objectives of the program, the pedigree complexity of newly generated populations, and the overall success of the program’s primary breeding goal – fire blight resistance.
Speakers
avatar for Christopher Gottschalk

Christopher Gottschalk

USDA ARS
During his Ph.D. studies, Dr. Gottschalk studied the molecular mechanisms that control flowering in apple as they relate to seasonal bloom times and biennial/alternate bearing in diverse apple germplasm, from wild species to cultivated varieties. Moreover, he investigated plant growth... Read More →
Friday September 27, 2024 2:15pm - 2:30pm HST
Kahili

2:15pm HST

LOCSY - Louisiana Harvest of the Month – Promoting Local Food and Food Literacy
Friday September 27, 2024 2:15pm - 2:30pm HST
The Louisiana Harvest of the Month (HOM) is program that is intended to introduce locally grown food such as fruit and vegetables one time per month to schools. The program started as a pilot program in 2015 in three schools in Louisiana and expanded statewide in 2017. The HOM program is currently in 720 schools around the state and is also used by other programs such as Louisiana 4H. The HOM program highlights a local food item designated by schools with monthly materials such as HOM posters, activity sheets, coloring pages, recipes, sample newsletters, taste test guide and “I tried it stickers,” classroom activities and lessons linked to state standards, all available free of charge. There are 21 HOM items currently available to participants with a majority of the HOM items locally available fruits and vegetables, along with rice, and several proteins (crawfish, catfish, shrimp). The newest additions to the HOM portfolio of resources are short (12 to 14 minute) videos produced by Louisiana Public Broadcasting that are targeted to elementary school children. The videos highlight farmers and fishers on location for each HOM and also provide a section in the use of the local product in the kitchen and demonstrate recipes. There are currently 18 HOM videos and their popularity is demonstrated by some having been accessed over ten thousand times on YouTube and Facebook. Data from the HOM program will be presented including data on the use of the program and program analytics.
Speakers
CM

Carl Motsenbocker

Professor, Executive Director Louisiana Farm to School Program, Louisiana State University
Dr. Carl Motsenbocker is a professor of horticulture and sustainable agriculture at Louisiana State University. Motsenbocker is Executive Director of the Louisiana Farm to School Program and teaches Organic Gardening, Sustainable Agriculture and Vegetable Crops at LSU. Motsenbocker... Read More →
Co-authors
CH

Celeste H. Finney

Louisiana State University Agricultural Center
NA
CB

Crystal Besse

Louisiana State University Agricultural Center
NA
JA

Jacey A. Wesley

Louisiana State University Agricultural Center
NA
TB

Tyne Bankester

Louisiana State University Agricultural Center
NA
Friday September 27, 2024 2:15pm - 2:30pm HST
South Pacific 1

2:15pm HST

O/LT 3 - Seedling Zoysiagrass Response to Fluazifop-butyl and Trifloxysulfuron-methyl With the Safener Metcamifen
Friday September 27, 2024 2:15pm - 2:30pm HST
Managing grassy weeds in turfgrass can be challenging. In 2023 a new formulation of trifloxysulfuron-methyl containing the safener metcamifen, Recognition® Herbicide, was commercially available for use in established zoysiagrass. When applied as a mixture, this product safens zoysiagrass from the effects of the graminicide fluazifop-butyl (Fusilade® II Herbicide), allowing for higher application rates of fluazifop-butyl to manage difficult to control grass weeds such as bermudagrass. Previous research has demonstrated acceptable response following this herbicide mixture when applied to established zoysiagrass, however no information is available evaluating seedling zoysiagrass response to these herbicides. Experiments were conducted at the Milo J. Schult Agricultural Research and Extension Center in Fayetteville, AR and the Southwest Research and Extension Center in Hope, AR in 2023 to evaluate seedling zoysiagrass injury from applications of fluazifop-butyl and trifloxysulfuron-methyl with metcamifen applied at two different rates. “Zenith” zoysiagrass was seeded in June and August in Fayetteville and Hope, respectively, with herbicide applications made 2-and 4-weeks after emergence. Similar response was observed from both 2- and 4- week after emergence herbicide application timings. When applied as a mixture to seedling zoysiagrass, treatments of fluazifop-butyl plus trifloxysulfuron-methyl with metcamifen resulted in a maximum of 20% visual injury 1-week after treatment. However, seedling recovery was observed at subsequent ratings with
Speakers
HW

Hannah Wright-Smith

Extension Weed Specialist, University of Arkansas
Co-authors
DN

David Nistler

University of Arkansas
NA
JM

John McCalla

University of Arkansas
NA
LT

Lane Tredway

Syngenta
NA
MD

Michael D Richardson

University of Arkansas
NA
Friday September 27, 2024 2:15pm - 2:30pm HST
South Pacific 2

2:15pm HST

PNM 3 -The Effects of Nutrient Management on Yield in Cut-and-Come-Again Kale Production.
Friday September 27, 2024 2:15pm - 2:30pm HST
Cut-and-come-again, or repeat harvesting, is a practice in which a single planting of greens is harvested on multiple occasions. This is a common practice among small-scale, urban, and home producers in which the outermost leaves are removed, leaving the growing center of the plant intact enabling multiple harvests without compromising plant health. As this practice is not common among large-scale and commercial producers, there are currently no research-based fertilizer recommendations for cut-and-come-again greens. General guidance simply suggests continued, nitrogen-heavy fertilizer applications to ensure repeated harvests. This type of guidance is not easy to follow for beginners or for growers looking to improve their cut-and-come-again yields. An experiment was designed to examine eight different fertilizer application strategies to determine which provided better growth and nutritional quality in later kale harvests while limiting nutrient leaching. Fertilizer applications for the cut-and-come-again treatments (CC) ranged from an initial fertilizer application matching local nutrient recommendations, to repeated applications either the initial complete application or a nitrogen side dressing at every third, every other, or at each harvest. A single harvest control (ODB) was also harvested at the baby stage at each CC harvest. At each harvest, total and marketable yield were measured and crop quality for marketability was assessed per the USDA guidelines for kale and greens. There were more issues with slow growth, slow regrowth, and missing harvests for pots in the fall than the spring, and more issues in 2023 than in 2022. Some issues were directly related to significant caterpillar damage in the fall of 2023 which also affected the marketability of the leaves harvested. The expected dose response to fertilizer treatment was not observed in any growing season of the two years of the study completed so far. While some differences in yield between treatments were observed, these were predominantly between the ODB control and CC treatments, but not among CC treatments. The expected drop in yield with successive harvests was also not consistently observed in CC treatments. The CC treatment receiving only the initial fertilizer application exhibited a drop in yield with successive harvests in only two of the four growing seasons. Further examination of the fate of nutrients in the leaf material, soil and leachate from the experiment should explain these unexpected results and provide more clarity on an optimal fertilizer treatment.
Speakers
LW

Leigh Whittinghill

The Connecticut Agricultural Expeirment Station
Friday September 27, 2024 2:15pm - 2:30pm HST
Lehua Suite

2:15pm HST

POM 4 - Nutritional Dynamics and Horticultural Performance of Peach Orchard in the United States in Response to Different Soil Amendment Programs.
Friday September 27, 2024 2:15pm - 2:30pm HST
Compost, mulch and manures have been reported as a potential substitute for synthetic fertilizer in fruit orchards, can improve soil health as well as increase the sustainability of orchard systems. In this study, we compared two rates (10 tons/acre as compost 1x and 20tons/acre as compost 2x) of pre-plant incorporation of food waste compost (FWC) and growers’ standard rate of inorganic/chemical fertilizer (control) of a replanted and virgin peach orchards in South Carolina. Measurement includes soil health indicators such as soil nutritional status and macronutrient dynamics, yield, and fruit quality (specifically on the incidence of diseases and physiological disorders). We hypothesized that the pre-plant incorporation of organic matter with subsequent topical application would improve soil moisture and nutrient availability, increase yield, and enhance the quality of marketable fruits. Higher cation exchange capacity and buffering capacity was recorded in soil treated with FWC than in the control treatment. In the replanted orchard, the 2x treatment resulted in improving soil health indicators such as SOM, cation exchange capacity, phosphorus, soil infiltration, and soil moisture, but not in the virgin orchard compared to the control treatment. Soil extractable P was higher in the FWC treatment as compared to the control treatment, while the soil extractable K ranges from high to excessive K across all treatments. No significant difference between the yields from both orchards. However, we observed numerical differences in the yields of the 2x treatment compared to the 1x and control treatments. Our results show that the yearly application of compost provides the orchard’s nutritional requirement, increases yield, and lower disease pressure in both orchards compared to the control treatments.
Speakers
avatar for Ayodeji Idowu

Ayodeji Idowu

Graduate Research and Teaching Assistant, Clemson University
Ayodeji Idowu is an adept researcher and an agricultural enthusiast with a diverse agricultural background. He received his B.S. in Plant Science, MBA in Agribusiness from Nigeria, and M.S. in International Agricultural Development from Tokyo University of Agriculture, Tokyo, Japan... Read More →
Co-authors
GS

Guido Schnabel

Clemson University
NA
JC

Juan Carlos Melgar

Clemson University
NA
Friday September 27, 2024 2:15pm - 2:30pm HST
South Pacific 3

2:30pm HST

CE 9 - Light Intensity Regulates the Interactive Effects between Far-red light and Temperature on Lettuce Growth, Morphology, Photosynthesis, and Secondary Metabolite
Friday September 27, 2024 2:30pm - 2:45pm HST
Phytochromes (PHYs) play a dual role in sensing light spectral quality and temperature. PHYs can interconvert between their active and inactive forms upon absorption of red and far-red light (Photoconversion). In addition, the active form can be converted to the inactive form in a temperature-dependent manner (Thermal Reversion). Our recent research found that while far-red (FR; 700-800 nm) light promoted leaf expansion and biomass of lettuce (Lactuca sativa) ‘Rex’ under cooler temperatures (20-24 °C), it reduced plant biomass and leaf area under warm temperature (28 °C). Considering that PHY activity would be driven mainly by photoconversion, not thermal reversion, under higher light intensity (HL), we hypothesized that the magnitude of the interaction between FR light and temperature on plant growth and morphology decreases with increasing light intensity. Lettuce ‘Rex’ was grown under three temperature regimes (20, 24, and 28 oC) x two spectral treatments [0 and 20% of FR light in total photon flux density (TPFD; 400-800 nm)] x two light intensities [150 (lower light intensity; LL) and 300 (HL) μmol·m-2·s- 1 of TPFD]. Our results showed that the effects of FR light on leaf expansion and stem elongation depended on temperature under LL. Specifically, FR light significantly promotes leaf expansion under cooler temperatures (20 oC), while decreasing total leaf area under warmer temperatures (24 and 28 oC). However, the magnitude of the interactive effects between FR light and temperature on plant morphology decreased under HL, leading to a consistent increase in total leaf area by FR light under HL. Similarly, FR light promoted plant growth under HL regardless of temperature, while reducing plant biomass under warm temperature under LL. Crop yield was primarily dependent on photon capture rather than photosynthetic efficiency per unit leaf area. FR light generally decreased the production of secondary metabolites (e.g., phenolics and flavonoids), while warm temperature and HL treatments increased the production of secondary metabolites. We concluded that the interactive effects between FR light and temperature on plant growth and morphology are further dependent on light intensity. The combination of FR light, warm temperature, and HL could maximize crop yield without reducing nutritional quality in terms of antioxidant capacity.
Speakers Co-authors
GN

Genhua Niu

Texas A
SZ

Shuyang Zhen

Texas A
NA
Friday September 27, 2024 2:30pm - 2:45pm HST
Nautilus

2:30pm HST

FRBR 2 - Differential Thermal Analysis of Cold Hardiness in Interspecific Hybrid Grapevine for Breeding Applications
Friday September 27, 2024 2:30pm - 2:45pm HST
Interspecific hybrid grapevine cultivars have been developed to expand grape cultivation into cold-climate areas. Cold weather events can lead to bud death and trunk injury which reduce yields and can result in plant death. Phenotyping cold hardiness is challenging, and developing a standardized phenotypic protocol would enable efficient evaluation of University of Minnesota grape breeding germplasm. The objective of this study is to utilize differential thermal analysis as an assay to quantify the low temperature exotherm response of grapevine buds. We phenotyped 28 varieties and advanced breeding selections from October 10th, 2023 through March 20th, 2024. Commercial cultivars (e.g. Marquette, Itasca, Frontenac) and breeding selections (wine grape, table grape, and rootstocks) were sampled weekly or bi-weekly based on availability of plant material. Differences in acclimation and deacclimation patterns between time points were observed in the low temperature exotherm readings, indicating that there may be differences in the genetic mechanisms for cold hardy responses. After the coldest day of the season, January 14, 2024, which had a low of -23°C, the temperature at which 50% of the buds would die, or LT50, for ‘Marquette’, ‘Itasca’, and ‘Frontenac’ were -29.7 °C, -30.9 °C, and -30.5 °C, which is consistent with field observations. The LT50s were rated at lower temperatures than the ambient air temperature, thus all genotypes were able to survive the weather conditions for this cold event. Future analysis aims to utilize K-means cluster analysis to determine groups that differ in responses to winter fluctuations in temperature and to determine the genetic controls for these responses.
Speakers
DV

Douglas Vines

University of Minnesota
Co-authors
MC

Matthew Clark

University of Minnesota
NA
SL

Soon Li Teh

University of Minnesota
NA
Friday September 27, 2024 2:30pm - 2:45pm HST
Kahili

2:30pm HST

GG 5 - Breeding for Photoperiod Insensitive and Indeterminate Flowering Habit in Pigeonpea
Friday September 27, 2024 2:30pm - 2:45pm HST
Pigeonpea [Cajanus cajan (L.) Mill.] is an important legume consumed in the Caribbean basin. Cultivars with indeterminate flowering habit have sensitivity to the photoperiod in Puerto Rico. The objectives of this research were to: (1) develop two breeding lines with indeterminate flowering habit that can be planted year-round, and (2) evaluate their agronomic performance. IIPG-7 and IIPG-11 breeding lines, derived from the bi-parental cross ‘ICPL 86012’/‘Guerrero’, were developed by pedigree and bulk breeding methods. Both breeding lines, their parents, and cultivars checks were tested in field trials in Isabela and Lajas, Puerto Rico in 2022 and 2023. IIPG-7 and IIPG-11 were early genotypes that initiated flowering between 73-84 days after planting (dap), and reached harvesting maturity at 121-127 dap compared with indeterminate cultivars ‘Ariel’, ‘Blanco Yauco’, ‘Kaki’, ‘Pinto Berrocales’, and ‘Super Pinto’ that initiated flowering between 91 to 102 dap and reached maturity at 138-148 dap. These cultivars had seed yield values over 1,000 kg/ha while IIPG-7 and IIPG-11 produced between 721 to 1,010 kg/ha under short day conditions in both locations. In contrast, IIPG-7 and IIPG-11 were the only indeterminate genotypes that initiated flowering between 42-88 dap, reached maturity between 88-172 dap, and seed yields varied from 626 to 2,449 kg/ha under long day conditions in Isabela and Lajas. These new breeding lines can be used to develop pigeonpea cultivars with insensitivity to the photoperiod.
Speakers
DV

Diego Viteri

University of Puerto Rico at Mayagüez
Co-authors
AL

Angela Linares Ramirez

University of Puerto Rico
Friday September 27, 2024 2:30pm - 2:45pm HST
Coral 1

2:30pm HST

LOCSY - Enhancing Food Security and Sovereignty: A Case Study of the University of Connecticut Federally Recognized Tribes Extension Program
Friday September 27, 2024 2:30pm - 2:45pm HST
The development of the University of Connecticut (UConn) Federally Recognized Tribes Extension Program (FRTEP) was a response to the need to enhance food security and sovereignty within the Mashantucket Pequot Tribal Nation (MPTN), while also reducing rates of obesity and Type II diabetes as the Tribal community faced food insecurity, alongside alarming rates of health disparities compared to their white counterparts. The program aimed to bolster agricultural capacity on Tribal lands, provide workforce development for Tribal members, and deliver health and nutrition education. Through extensive consultations with Tribal leaders and members, UConn FRTEP tailored programs in agriculture, workforce development, youth engagement, and health education. Since the initiation of the program in 2017 to 2023, Extension educators provided comprehensive training on vegetable and fruit production, integrated pest management, and business planning. Additionally, nutrition workshops, fitness classes, and virtual cooking sessions were conducted, fostering community engagement. Tribal youths engaged in educational activities and field trips designed to enhance agricultural literacy and healthy eating behaviors. To ensure sustainability, youths also participated in “train the trainer” opportunities. Project evaluations included resource inventories, focus groups, and pre/post-program surveys to measure immediate outcomes as well as broader impacts and community perceptions. The establishment of a farm that included hydroponic greenhouses, shipping-container farming, in addition to growing an array of vegetables and fruits on 5 acres by 2023 improved food security and sovereignty within MPTN. The farm produced tomatoes, lettuce, summer squash, winter squash, cucumbers, watermelon, chard, broccoli, potatoes, beans, herbs, and strawberries, supporting food distribution programs reaching 15% (180 members) of the Tribal population in 2022 and 2023. Additionally, in the same period, 30 diabetic patients received prescribed fresh produce from the farm. After completing nutritional education lessons (seven 1-hour long) in 2022, survey results indicated notable improvements among youth participants (n = 17): 60% showed enhanced ability in identifying active children, 50% improved recognition of fruits and dairy foods, and 44% exhibited better proficiency in identifying healthy snacks. Overall, the health of the tribal members improved through the consumption of fresh nutritious food, an increase in the number of tribal members practicing healthy eating habits, and exercise learned through training. The success of the project led to the creation of the MPTN Department of Agriculture. UConn FRTEP significantly strengthened university-tribal relations, exemplifying fruitful collaboration, boosting food security, economics, and health. This model partnership promotes sustainable development, empowering Indigenous communities, fostering resilience, and self-reliance.
Speakers
SG

Shuresh Ghimire

University of Connecticut
NA
Co-authors
EB

Erica Benvenuti

University of Connecticut
NA
JB

Joseph Bonelli

University of Connecticut
NA
MP

Michael Puglisi

University of Connecticut
NA
RR

Robert Ricard

University of Connecticut
NA
ST

Sara Tomis

University of Connecticut
NA
Friday September 27, 2024 2:30pm - 2:45pm HST
South Pacific 1

2:30pm HST

O/LT 3 - Influence of Demethylation Inhibiting Fungicides on Creeping Bentgrass Putting Greens
Friday September 27, 2024 2:30pm - 2:45pm HST
Demethylation inhibiting (DMI) fungicides are frequently applied to turfgrasses for suppression of many common fungal diseases in turfgrass. However, certain DMI fungicides cause phytotoxic effects to turfgrasses, particularly creeping bentgrass (Agrostis stolonifera L.), during the heat of the summer. A study was conducted in Fayetteville, AR in the summer of 2023 to determine the effects of nine DMI fungicides (flutriafol, mefentrifluconazole, metconazole, myclobutanil, propiconazole, prothioconazole, tebuconazole, triadimefon, and triticonazole) compared to a nontreated control on a ‘Pure Eclipse’ creeping bentgrass putting green. All treatments were applied a total of six times at the highest labeled rate at biweekly intervals beginning on 23 Jun 2023 and ending on 1 Sep 2023. A CO2-pressurized backpack sprayer was used to deliver the treatments in a carrier volume of 814 L ha-1. Plots were assessed weekly for percent phytotoxicity (0-100%). Additionally, beginning on 27 Jul 2023, clippings were collected, dried, and weighed weekly until 24 Aug 2023. Data were averaged across all rating dates, subjected to analysis of variance, and means were separated using a Student’s t-test (p < 0.05). Propiconazole caused ≥ 36.7% more phytotoxicity than any other treatment. The only other fungicide treatments that caused greater phytotoxicity than the nontreated control were myclobutanil and triadimefon. Myclobutanil, propiconazole, and triadimefon were also the only treatments to increase clipping weights compared to the nontreated control. These data suggest that many DMI fungicides do not cause phytotoxic effects on creeping bentgrass putting greens during the summer with the exception of myclobutanil, propiconazole, and triadimefon.
Speakers
WH

Wendell Hutchens

Assistant Professor of Turfgrass Science, University of Arkansas
Wendell Hutchens, PhD is an assistant professor of turfgrass science in the Horticulture Department at the University of Arkansas. His main areas of expertise are turfgrass pathology and precision management of turfgrass pests using emerging technologies. His research program is centered... Read More →
Co-authors
JA

Jessica Anders

University of Arkansas
NA
KG

Koa Grabar

University of Hawaii at Manoa
NA
MB

Michael Battaglia

University of Arkansas
NA
Friday September 27, 2024 2:30pm - 2:45pm HST
South Pacific 2

2:30pm HST

PNM 3 - Optimization of Tissue Culture Medium for Enhanced Proliferation of Little-Leaf Mockorange (Philadelphus microphyllus A.
Friday September 27, 2024 2:30pm - 2:45pm HST
Native plants play a crucial role in landscape ecosystems due to their adaptability, yet propagating certain species through traditional methods can pose challenges. Tissue culture emerges as a promising alternative for efficient propagation, demanding an optimized culture medium for desirable proliferation. Efficient proliferation of newly introduced plant species in tissue culture often necessitates meticulous experimentation with varying salt compositions to optimize mineral concentrations and growth regulator levels within the culture medium. This study aimed to employ Response Surface Methods (RSM) to assess the effects of different mineral combinations, including nitrogen (N), calcium (Ca), potassium (K), and phosphorus (P), along with a cytokinin (zeatin), on the shoot proliferation and growth of little-leaf mockorange in tissue culture. Forty-six treatment combinations were designed, with zeatin concentrations of 0.82, 1.095, or 1.37 µM, and varying levels of N (22.5, 30, or 37.5 mM), Ca (1.125, 1.5, or 1.88 mM), P (0.31, 0.625, or 0.94 mM), and K (5, 10, or 15 mM). These treatments were evaluated for their impact on axillary shoot formation, shoot length, and shoot dry weight. Response surface analyses revealed optimal concentrations of N (32.5 to 35 mM), Ca (1.5 mM), and P (0.625 mM), while the influence of potassium on responses was found to be nonsignificant in the regression models, hence, K concentrations were limited to linear trends in the analysis. Notably, medium supplemented with 1.1 µM zeatin demonstrated a significant positive impact on shoot proliferation. The RSM model demonstrated the feasibility of determining optimal concentrations of zeatin, N, Ca, and P in a single experiment, facilitating the in vitro growth of little-leaf mockorange shoots. This study underscores the efficacy of RSM in tissue culture experiments, offering a time- and cost-effective alternative to conducting multiple separate experiments and providing valuable insights into medium optimization. Such findings contribute to the advancement of tissue culture techniques, particularly in propagating native plant species critical for landscape sustainability.
Speakers
avatar for Razieh Khajehyar

Razieh Khajehyar

Scientist, University of Idaho, Germains Seed Technology, Inc.
Co-authors
RT

Robert Tripepi

University of Idaho
NA
SL

Stephen Love

University of Idaho
NA
WJ

William J. Price

University of Idaho
NA
Friday September 27, 2024 2:30pm - 2:45pm HST
Lehua Suite

2:30pm HST

POM 4 - Influence of Low-, Medium-, and High-Chill Requirement Rootstocks on the Metabolomic Profile of Low-Chill Peaches
Friday September 27, 2024 2:30pm - 2:45pm HST
Rootstocks are widely used for commercial orchard establishments throughout the world, as they facilitate scion adaptation to challenging edaphic and environmental conditions, as well as mitigate the impact of pests and diseases. Furthermore, rootstocks may influence physiological, biochemical, or phenological processes in the scion. Nevertheless, little is known about the influence of rootstocks on metabolomic profiles of Prunus scions, particularly in low-chill cultivars. This study aimed to determine the influence of rootstocks with varied chilling requirements on the metabolomic profiles of low-chill peaches. Scion ‘UFSun’ was grafted on low-(Flordaguard), medium-(P-22), and high-(MP-29, Guardian, and Nemaguard) chill requirement rootstocks, and grown in a greenhouse in Gainesville, Florida. Vegetative tissue samples were collected for extraction of metabolites. Untargeted compounds were analyzed using an Orbitrap Fusion Tribrid mass spectrometer system, interfaced with an automated A VanquishTM UHPLC system, and a total of 152 metabolites were detected. Potential differences in metabolomes associated with the rootstocks were analyzed by performing a partial least square–discriminant analysis (PLS-DA), although it was not possible to determine group differences when comparing all treatments. An orthogonal PLS-DA approach supported by permutational MANOVA test was implemented for paired comparison of plants grafted on Flordaguard (rootstock recommended for commercial production in Florida) vs. all other rootstocks, and differences were observed for all comparisons. For further confirmation of these results, and determination of the metabolites potentially differentially expressed due to rootstock influence, the Empirical Bayesian Analysis of Microarrays (EBAM) approach was implemented, as adjusted for analysis of metabolites in MetaboAnalyst 6.0. A total of 85, 52, 0, and 61 metabolites were dimmed as potentially differentially expressed when comparing trees grafted on Flordaguard vs. P-22, MP-29, Guardian, and Nemaguard, respectively. Most of these metabolites may be flavonoids, phenylpropanoids, and polyketides. According to our observations, low-, medium-, and high-chill rootstocks can influence the metabolomic profile of low-chill scions.
Speakers
JC

Jonathan Clavijo Herrera

University of Florida
Co-authors
AS

Ali Sarkhosh

University of Florida
NA
LR

Lorenzo Rossi

University of Florida
Friday September 27, 2024 2:30pm - 2:45pm HST
South Pacific 3

2:45pm HST

CE 9 - Lighting Around the Clock: Greenhouse Production with 24h Lighting
Friday September 27, 2024 2:45pm - 3:00pm HST
Photoperiod extension in controlled environment agriculture - including the use of 24h continuous light - can be used to reduce light fixture and electricity costs in regions with lower night electricity rates. However, many plant species develop photoperiodic injury characterized by leaf chlorosis and yield reduction at a critical species-specific photoperiod threshold. Here we will discuss the response of different plant species to continuous lighting strategies. We will first challenge the conventional notion that dark adapted chlorophyll fluorescence (Fv/Fm) measurements are the most appropriate when assessing photoperiodic injury. We provide evidence that light adapted (φPSII) measurements allow for a more in-depth understanding of the light capture process at photosystem II. Through RNA-sequencing in tomato, we determined that the use of a dynamic 24h lighting treatment (i.e., red light during the day and blue light during the night) lead to normal gene expression of chlorophyll a/b binding (CAB) proteins. However when tomato plants were grown under a static continuous lighting strategy (i.e., red blue lighting for 24h) at the same daily light integral, gene expression of CAB proteins were drastically reduced, resulting in chlorosis and yield reduction. In comparison to tomatoes, cucumbers tend to be more tolerant to long photoperiods and therefore continuous lighting can have an immediate impact in commercial production. Initial results in cucumbers show that a continuous lighting strategy can decrease the lighting electricity costs by 26% and greenhouse gas emissions by 38.9% per unit of produce compared to a 16h control treatment. Using the knowledge gained throughout our studies, we propose a lighting strategy which gamifies the electricity market to further reduce costs and greenhouse gas emissions.
Speakers
JL

Jason Lanoue

Agriculture
Co-authors
QD

Quade Digweed

Agriculture
NA
XH

Xiuming Hao

Agriculture
NA
Friday September 27, 2024 2:45pm - 3:00pm HST
Nautilus

2:45pm HST

FRBR 2 - Ovary and Fruit Shape Variation Associated with Novel ClSUN25-26-27a Alleles in Watermelon
Friday September 27, 2024 2:45pm - 3:00pm HST
The genetic mechanisms controlling fruit morphology in watermelon is not fully understood. Only one candidate gene, ClSUN25-26-27a (Cla011257), has been identified as a significant contributor to the ovary and fruit shape. ClSUN25-26-27a is a member of the SUN gene family, which has been extensively studied in relation to fruit morphology in tomatoes. In tomato, the effect on fruit shape facilitated by this gene is detectable during the early stages of fruit development, with the cell patterns established pre-anthesis. In watermelon, three alleles of ClSUN25-26-27a are known to be associated with ovary and fruit shape variation: the wild-type, a SNP, and a 159bp deletion in the 3rd exon. This study aims to determine the effect of the novel allelic variation for ClSUN25-26-27a on ovary and fruit shape. Four novel alleles have been identified and sequenced in the coding region of ClSUN25-26-27a across three Citrullus species. Marker assisted backcrossing was used to introgress the different alleles into a common genetic background. The NILs were phenotyped in the field to determine the effect of the novel alleles on ovary and fruit shape. Ovary length and width were measured four days pre-enthesis, at anthesis, and four days post-anthesis and used to calculate the ovary shape index (OSI). Mature fruit was also phenotyped using Tomato Analyzer. One of the novel alleles was significantly associated with ovary and fruit shape. These findings contribute to the understanding of the important SUN gene family and the genetic mechanisms contributing to watermelon fruit shape. Future research will determine the gene expression patterns of the different alleles and the effect of the alleles on the cell number or cell size in watermelon.
Speakers
SJ

Samuel Josiah

University of Georgia
Co-authors
CM

Cecilia McGregor

University of Georgia
Friday September 27, 2024 2:45pm - 3:00pm HST
Kahili

2:45pm HST

GG 5 - Breeding for Improved Tomato Flavor
Friday September 27, 2024 2:45pm - 3:00pm HST
Consumers are dissatisfied with the flavor of modern commercial tomatoes; however, modern tomato varieties have many desirable agronomic traits such as shelf life, disease resistance and yield. The flavor deficiency in modern tomatoes is due to a cumulative loss of superior alleles affecting flavor volatiles while breeding for other traits. The lack of breeder focus on the consumer is largely due to the genetic complexity of the tomato flavor phenotype as well as a lack of a simple assay that can define consumer preferences. Tomato flavor is a result of interactions between sugars, acids and aroma volatiles, with volatile compounds giving the tomato fruit its characteristic aroma and flavor. We have quantified 68 flavor biochemicals in over 700 tomato varieties, including modern, heirloom and ancestral tomato accessions. Over 160 of these varieties were evaluated by a large consumer panel for fruit flavor quality traits including overall liking. Genome Wide Association Studies (GWAS) identified genetic loci associated with altered levels of acids, sugars and aroma volatiles. We have used marker-assisted breeding to introgress loci associated with flavor biochemical levels from heirloom varieties into modern tomato varieties. Introduction of seven flavor loci affecting a variety of flavor volatiles into a modern tomato variety has resulted in altered flavor volatile profiles and improved flavor as assessed by a consumer panel.
Speakers
DT

Denise Tieman

University of Florida
Co-authors
HK

Harry Klee

University of Florida
NA
MA

Modesta Abugu

North Carolina State University
NA
Friday September 27, 2024 2:45pm - 3:00pm HST
Coral 1

2:45pm HST

LOCSY - Response of Leafy Edibles Grown on an Extensive Greenroof Compared to Conventional Field Production
Friday September 27, 2024 2:45pm - 3:00pm HST
Urban green roof (GR) agriculture provides an alternative growing space to supply fresh produce and herbs to local markets or restaurants, which can also help to address food security concerns in cities, by providing nutritional produce in urban and often underserved locations. Although many vegetables can be grown on extensive GRs, few studies have evaluated the performance of edibles grown on green roof environments to those grown under typical field conditions. Unlike traditional agriculture, plants on extensive GRs are grown in a shallow engineered soil to reduce the weight load on the roof. Therefore, an experiment was conducted in 2023 on the Southern Illinois University – Carbondale Agriculture building extensive green roof and at the Horticulture Research Center. This experiment evaluated ‘Dazzling Blue’ and ‘Red Russian' Kale [Brassica oleracea (Acephala Group)], and ‘Green Wave’ Mustard (Brassica juncea) productivity in both an extensive green roof environment and open field conditions. Similar cultural practices were followed regarding plant spacing, fertilizer and water management in both systems. The experiment was setup as a CRD with two treatment locations evaluating three edible green varieties with four replications. Results indicated a significant yield cost for these leafy edibles when gown on the greenroof compared to the conventional field environment. Fresh weight of ‘Dazzling Blue’ and ‘Red Russian Kale were reduced by 85% and 80% when grown in the GR environment, respectively, while that for ‘Green Wave’ Mustard was decreased by 70%. Data for other growth variables, such as plant height and vigor, leaf count, and dry weight were also generally reduced in an extensive GR environment and will be presented and discussed further. Although our research indicates that extensive GRs do not provide similar yields for leafy green edibles as conventional field production, this alternative urban space used to grow fresh food for an urban community may more than make up for the loss in yield due to the various significant positive impacts that GRs can provide.
Speakers
KL

Kaitlyn Lamaster

Horticulture Instructor, Southern Illinois University
Co-authors
AW

Alan Walters

Southern Illinois University
HM

Hunter M Christenson

Southern Illinois University
NA
Friday September 27, 2024 2:45pm - 3:00pm HST
South Pacific 1

2:45pm HST

O/LT 3 - Endophytic N Fixing Bacteria Isolated From Warm-season Turfgrasses and Common Lawn Weeds
Friday September 27, 2024 2:45pm - 3:00pm HST
The turfgrass industry has attempted to adopt market available N fixing bacterial strains to supply exogenous N requirements. However, turfgrass inoculations with market available N fixing strains have led to inconclusive results. Research on naturally occurring N fixers has mainly focused on abundance and diversity on roots and below ground soil. These ecological niches are known to be impacted by regular management practices of turfgrass which also interfere with the colonization rates of microorganisms. Therefore, the use of endophytic N fixing bacteria which are naturally present in turfgrasses such as bermudagrass, creeping bentgrass, and tall fescue is an attractive alternative regarding a higher microbial stability and potential of colonization. In this study we evaluated the culturing potential of N fixing bacteria from three turfgrass and three common weed species, assayed their potential to grow under different ammonium chloride (NH4Cl ) concentrations, and compared the isolates with the dominant taxa from a previous study in the community composition of N fixing bacteria in ‘CitrablueTM’ St. Augustinegrass [Stenotaphrum secundatum (Waltz)]. The plant biomass was collected from ‘CitrablueTM’, ‘Celebration’ bermudagrass [Cynodon. dactylon (L.)], ‘Empire’ zoysiagrass [Zoysia japonica (Steud)], goosegrass [Eleusine indica (L.) Gaertn], crabgrass [Digitaria sanguinalis (L.) Scoop], and bull paspalum [Paspalum setaceum (Michaux)]. The biomass was washed with water and surface sterilized using consecutive immersions in ethanol 75%, bleach 50%, and three rinses with ultrapure water. After sterilization, N fixers were isolated using a N free enrichment technique with Carbon Combined Media (CCM) and streaking on CCM solid plates. Taxonomy of the isolates was assigned using 16S and nifH Illumina miseq sequencing, consequently, the isolates were grown in liquid CCM with NH4Cl concentrations ranging from 100 uM to 0.001 uM. The isolates, Sphingomonas trueperi, Kosakonia radicitans, Herbaspirillum rubrisulbicans, Agrobacterium salinotolerans, Stenotrophomonas maltophilia, Kosakonia oryzae, Enterobacter sp. were not able to grow below 1 uM of NH4Cl in liquid CCM, however, these strains were the best performing strains because were able to grow at lower NH4Cl concentrations. Lastly, the isolates were not genotype specific to either turfgrasses or weeds and were not correlated with the dominant taxa of N fixers on the ‘CitrablueTM’ study.
Speakers
AF

Andrea F Arevalo Alvarenga

Graduate Assistant, University of Florida
Co-authors
MS

Marco Schiavon

University of Florida
US

Ulrich Stingl

University of Florida
NA
Friday September 27, 2024 2:45pm - 3:00pm HST
South Pacific 2

2:45pm HST

PNM 3 - Nano NPK and Salicylic Acid Chemigation in Processing Tomato Production: Impact on Efficiency and Sustainability
Friday September 27, 2024 2:45pm - 3:00pm HST
Chemical fertilizers are key to enhancing tomato productivity, yet their excessive or imbalanced use can lead to higher costs, energy inefficiency, and negative environmental impacts. Recent advancements in nano fertilization seek to optimize nutrient use, minimize losses, and improve farm economics and environmental sustainability. Additionally, salicylic acid (SA) as a chemical inducer has shown potential to boost crop yields by enhancing stress tolerance in plants. Our research evaluated the effects of various rates of nano NPK fertilization combined with SA chemigation on the efficiency and sustainability of processing tomatoes (Solanum Lycopersicum L., cv. BHN 685) production in a drip-irrigated plasticulture system. Conducted over the 2022 and 2023 growing seasons, this two-factorial experiment tested nano NPK rates (0, 40, 80, 120 kg/ha) and SA levels (0 vs. 0.3%), using conventional NPK fertilizers as the control. The results showed that tomato yields were significantly influenced by SA chemigation, nano NPK fertilization, and the growing year, without interactive effects between and among these factors. SA chemigation with 120 kg NPK/ha increased yields by 9% compared to the control. Yields were similar between the 120 kg/ha SA chemigation and 120 kg/ha nano NPK treatments but were significantly higher (by 21%) under the 120 kg nano NPK with SA chemigation, suggesting effective synergy between SA and nano fertilization. SA chemigation and NPK fertilization reduced cull fruit yields, with nano NPK showing the most substantial reduction. Production costs were slightly higher for the combination of SA chemigation and nano NPK ($7,114/ha), but profitability was significantly increased, peaking at $2,487/ha in this treatment. Energy use efficiency also increased from 42.3% in the control (120 kg NPK/ha) to 51.1% with the combined treatment (120 kg nano NPK/ha with SA chemigation), and specific energy use per unit of tomato was decreased from 1.9 MJ/kg to 1.6 MJ/kg. Greenhouse gas emissions per ton of tomato were reduced from 46.3 kg CO2 equivalent/ha in the control to 42.7 kg/ha with combined nano NPK and SA chemigation. In conclusion, nano NPK fertilization coupled with SA chemigation proves to be an effective strategy for enhancing the efficiency and sustainability of processing tomato production, improving yield, profitability, and environmental outcomes.
Speakers
TH

Thomas Harker

Research Assosiate, The Ohio State University
Thomas Harker currently holds a research associate position specializing in horticultural and specialty crops at the Ohio State University South Centers. With an extensive career spanning over 25 years, he has been deeply immersed in the exploration and enhancement of various crops... Read More →
Co-authors
AR

Arifur Rahman

The Ohio State University South Centers
NA
BB

Brad Bergefurd

Brandt Discovery
NA
EB

Ed Brown

The Ohio State University Extension Athens County
NA
RI

Rafiq Islam

The Ohio State University South Centers
NA
WL

Wayne Lewis

The Ohio State University South Centers
NA
ZG

Zhenhao Guan

The Ohio State University South Centers
NA
Friday September 27, 2024 2:45pm - 3:00pm HST
Lehua Suite

2:45pm HST

POM 4 - Effects of plum tree architecture on canopy light environments and fruit quality
Friday September 27, 2024 2:45pm - 3:00pm HST
In the orchard production system, upright or pillar trees with vertical branch orientations have narrow architecture profiles and therefore can be suited to high-density planting to increase productivity. In plum (Prunus domestica), there are natural variations of tree forms that range from upright to more horizontal growth habit. Recently, researchers at the USDA-ARS Appalachian Fruit Research Station demonstrated that silencing TILLER ANGLE CONTROL 1 (TAC1) via RNA interference (RNAi) in ‘President’ plum led to pillar tree forms with upright lateral shoot growth, whereas silencing LAZY1 in ‘Stanley’ plum resulted in outward shoot orientations and weeping tree shape. The objective of this study was to assess the effects of tree architectures on canopy light availability and fruit quality using field-grown mature (7-year-old) TAC1 and LAZY1 silenced plum trees in comparison with their respective non-transgenic counterparts as controls. Our results indicated that slender canopy profiles due to silencing of TAC1 allowed significantly greater light availability without negative impacts on fruit size, soluble solids contents, or titratable acidity compared to non-transgenic plum with the same genetic background. Additionally, skin color of fruit was more uniform in TAC1-RNAi lines than in standard-shaped control trees, suggesting a positive correlation between canopy light distribution and fruit coloration in association with upright branch orientations. In contrast, light availability in LAZY1-RNAi tree was reduced significantly by over 50% compared to the control. Although there is no difference in fruit size, soluble solids content in fruit of the LAZY1-RNAi plum than that of the non-transgenic counterpart.
Speakers
LT

Lisa Tang

USDA-ARS Appalachian Fruit Research Station
Co-authors
CD

Chris Dardick

Innovative Fruit Production, Improvement and Protection, Appalachian Fruit Research Station, Agricultural Research Service, (USDA)
NA
MF

Macarena Farcuh

University of Maryland
Friday September 27, 2024 2:45pm - 3:00pm HST
South Pacific 3

3:00pm HST

CE 9 - Explore a Cost-friendly Way for Plant Nitrogen Stress Identification
Friday September 27, 2024 3:00pm - 3:15pm HST
Plant stress can cause economic loss for plant production and is hard and expensive to identify at times. Thus, a greenhouse experiment was conducted to find an easy and cost-friendly way to identify plant stress, set up thresholds and values for the initiation of plant nitrogen stresses. Four different crops (basil, pepper, marigold, and sage) were included and treated with five different nitrogen levels (0%, 25%, 50%, 75%, and 100%). Plant height, width and leave greenless (indicated by SPAD) were measured weekly. Pictures were taken weekly. Software Image J was used to process pictures and R was used for data analysis. We found that plants with higher nitrogen treatments (75%-100%) all grow better and have higher SPAD than other treatments, except for bail. Also, RGB value could indicate plant nitrogen status with high accuracy. Plants become nitrogen stressed when SPAD falls to 25. Red and green values in RGB have negative correlations directly with SPAD and indirectly with nitrogen stress status. When the R and G values are higher than 150 and 185, respectively, we can safely predict that the plant is nitrogen stressed. In conclusion, using RBG value can be a cost-friendly way for plant stress identification.
Speakers
PY

Ping Yu

University of Georgia
Co-authors
KQ

Kuan Qin

University of Georgia
Friday September 27, 2024 3:00pm - 3:15pm HST
Nautilus

3:00pm HST

FRBR 2 - Linking Cultivar Evaluations – Phenology, Metabolomics, Consumer Preferences, and Postharvest Handling of ‘Glenn’ Mango
Friday September 27, 2024 3:00pm - 3:15pm HST
Mangos are the fifth most consumed fruit in the world (World Atlas). The top five mango producers include India, China, Indonesia, Pakistan, and Mexico (World population). Puerto Rico is the largest U.S. mango producer (2,666 acres), followed by Florida (2,455 acres), Hawaii (497 acres), California (328 acres), and Texas (10 acres). There are thousands of mango cultivars worldwide and the development and selection of new cultivars is ongoing. However, relatively few cultivars have a combination of information on their phenology, metabolomic profiles, consumer preferences, and postharvest handling. Describing and linking these cultivar evaluations and attributes may improve marker-assisted breeding efforts to develop and select for superior mango flavor, aroma, and nutritional value, improve understanding of hedonic consumer preferences, and result in improved postharvest handling and processing of mango. For example, ‘Glenn’ mango is a moderately vigorous tree with an upright open canopy that is generally dormant from November through December-January that flowers during February-March in response to warming ambient temperatures and is harvested during June-July. Historical descriptions are that it is a fruit of excellent eating quality with a rich, aromatic (pineapple notes) flavor, low fiber, and sweet pulp. This is borne out by the nonvolatile physiochemical characteristics of the cultivar including an average TSS of 15.93, TA of 0.65, and TSS/TA ratio of 24.41, with high concentrations of fructose, glucose, isocitric acid, and ketoglutaric acid. Defining nonvolatile flavor constituents from partial least-squares discriminant analysis for ‘Glenn’ mango were fructose, glucose, sucrose, isocitric acid, ketoglutaric acid, malonic acid, and gallic acid whereas defining volatile aroma constituents included ten esters (e.g., ethyl acetate, ethyl butanoate, and ethyl octanoate) that have floral, citrus, sweet, fruity, pineapple, and coconut notes. Results from a consumer sensory (taste, flavor, texture, fibrousness, juiciness, etc.) acceptance study indicated consumers like ‘Glenn’ mango because of its sweetness, tropical flavor, low fiber content, and juiciness, bearing out historical descriptions of this fruit. More detailed metabolic biosynthesis mapping linked flavor precursors and intermediates to the constituents responsible for flavor and aroma of ‘Glenn’. Postharvest evaluations reported ‘Glenn’ was moderately susceptible to hot water treatment injury, significant anthracnose incidence, only slight chilling injury (if stored below the 13°C recommended temperature) and could be stored for at least 3 weeks.
Speakers
avatar for Jonathan H Crane

Jonathan H Crane

Tropical Fruit Crop Specialist, University of Florida, TREC
Commercial tropical fruit production systems and information. I work with avocado, mango, lychee, longan, mamey sapote, papaya, passionfruit, dragonfruit, guava, annona, and others.
Co-authors
CS

Charles Sims

University of Florida IFAS
NA
JK

Jeffrey K Brecht

University of Florida, IFAS
NA
YW

Yu Wang

University of Florida
Friday September 27, 2024 3:00pm - 3:15pm HST
Kahili

3:00pm HST

GG 5 - Genome-Wide Association Study Identifies Key SNPs Associated with Mineral Element Accumulation in Spinach (Spinacia oler
Friday September 27, 2024 3:00pm - 3:15pm HST
Understanding the genetic basis of mineral element contents in crops is crucial for improving their nutritional value. This study conducted a comprehensive Genome-Wide Association Study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the accumulation of 14 essential mineral elements in spinach (Spinacia oleracea). Utilizing a diverse collection of 281 spinach accessions, we assessed the content of Boron (B), Calcium (Ca), Cobalt (Co), Copper (Cu), Iron (Fe), Potassium (K), Magnesium (Mg), Manganese (Mn), Molybdenum (Mo), Sodium (Na), Nickel (Ni), Phosphorus (P), Sulfur (S), and Zinc (Zn), expressed in micrograms or milligrams per gram of dry weight (µg/gDW or mg/gDW). Genotyping revealed 83,952 SNPs across the spinach genome, analyzed using GAPIT3 and TASSEL5 software platforms. Statistical models employed included General Linear Model (GLM), Mixed Linear Model (MLM), FarmCPU, and BLINK within GAPIT, alongside SMR and GLM in TASSEL. Our analysis uncovered 33 significant SNP-trait associations distributed among the minerals: one for B, Cu, P, and K; two for Ca, Ni, Fe, Zn, and S; three for Mo and Mg; four for Na and Co; five for Mn. These findings highlight the genetic diversity influencing mineral nutrient accumulation in spinach and offer valuable markers for breeding nutritionally enhanced spinach varieties.
Speakers
HX

haizheng xiong

University of Arkansas
Co-authors
avatar for Ainong Shi

Ainong Shi

Associate Professor, University of Arkasnas
Dr. Ainong Shi is a faculty member in the Department of Horticulture at the University of Arkansas. His research laboratory specializes in plant breeding and genetics, particularly focusing on vegetable crops such as arugula, cowpea, and spinach for cultivar and germplasm development... Read More →
HA

Hanan Alkabkabi

University of Arkansas
NA
IA

Ibtisam Alatawi

University of Arkansas
NA
KC

Kenani Chiwina

University of Arkansas
NA
Friday September 27, 2024 3:00pm - 3:15pm HST
Coral 1

3:00pm HST

LOCSY - Diverse Internships as an Opportunity to Engage Underrepresented Students Into Local Food Systems
Friday September 27, 2024 3:00pm - 3:15pm HST
Climate change, food insecurity, and environmental degradation are complex food system challenges that require innovative and interdisciplinary approaches to agricultural research and education. In addition to attracting and training more students to food system and agricultural careers, there is a critical need for targeted recruitment of under-represented groups. To meet the demand for skilled professionals and increase minority participation in the agricultural workforce, the Center for Environmental Farming Systems (CEFS) has been developing new internship programs that reflect the changing career paths, as well as diverse interests and needs of students. Over the past five years, CEFS has strategically redesigned and expanded our student internship opportunities. In 2023, CEFS hosted 5 different student internship programs with 37 students with opportunities that ranged from summer research intensives to remote year round opportunities where students worked with food based community nonprofits. Key aspects of all of our internship programs include paid work opportunities, experiential learning, mentorship, professional development opportunities and cohort based learning. All student participants participated in pre- and post tests designed to collect program evaluation, participant knowledge and skills gains, as well as participants' intended career choices. Over the past three years, more than 50% of all program participants were from underrepresented minority groups. Additionally, 54% of interns reported that program participation led to a career pursuit in agriculture or food systems. Short term follow up studies to date show the majority of participants are either working in agriculture or food systems or completing additional studies in a related field. By engaging these diverse undergraduate students in hands-on, agriculture and food system research and extension opportunities while providing structured professional development training, we have increased underrepresented student interest and capacity to pursue careers in agriculture and food systems.
Speakers
AC

Angel Cruz

North Carolina State University
Research Scholar at NC State University
Co-authors
SK

Sara Kidd

North Carolina State University
NA
Friday September 27, 2024 3:00pm - 3:15pm HST
South Pacific 1

3:00pm HST

O/LT 3 - Mowing Mediated Root Radial Transport of Lead in Cynodon dactylon (L.) Persoon
Friday September 27, 2024 3:00pm - 3:15pm HST
Moderate mowing has been demonstrated as an effective strategy for aiding soil Pb remediation using bermudagrass. However, the precise mechanisms by which mowing facilitates the absorption and transport of Pb in bermudagrass remain unclear. Radial transport of Pb in roots governs the amount of Pb loaded into xylem vessels, where Pb ions are translocated upward into shoots. This study aims to investigate the radial transport pathways and their characteristics of Pb in bermudagrass under Pb and mowing treatments to elucidate the underlying mechanisms. The results indicate a shift in Pb distribution within the bermudagrass roots under mowing treatments. Specifically, there was a decrease in Pb distribution in the root apoplast accompanied by an increase in the root symplast. Under mowing conditions, the synthesis of abscisic acid and jasmonic acid in roots was significantly induced, leading to a delayed development and deposition of the endodermal barriers (Casparian strips and suberin lamellae). This reduction in the contribution rate of the apoplastic bypass inhibited Pb from entering the stele via the apoplastic pathway. Conversely, mowing pretreatment inhibited Pb absorption in roots but promoted Pb absorption in shoots under treatments with metabolic and ion channel inhibitors. Additionally, Pb2 net influx in the root apex was remarkably enhanced, and the expression of Pb absorption- and transport-related genes (CdNramp5 and CdHMA2) were upregulated following mowing application, suggesting that mowing promoted Pb transport through the symplastic pathway. Overall, this study provides the first evidence that mowing mediates the radial transport of Pb in bermudagrass. Mowing enhances the absorption and root-to-shoot transport of Pb primarily by increasing the efficiency of the symplasmic pathway.
Speakers
XC

Xinyi Cai

University of Georgia
Co-authors
DZ

Donglin Zhang

University of Georgia
XL

Xi Li

Sichuan Agricultural University
NA
Friday September 27, 2024 3:00pm - 3:15pm HST
South Pacific 2

3:00pm HST

PNM 3 - Nano NPK and Salicylic Acid Chemigation on Tomato Phytochemicals and Fruit Quality
Friday September 27, 2024 3:00pm - 3:15pm HST
Tomato stands out as a premier high-value specialty crop globally. However, the inefficiency of conventional fertilizers in nutrient utilization necessitates excessive fertilization to maintain tomato yields, which adversely impacts fruit quality. Nanotechnology, aimed at precise nutrient management to enhance efficiency and economic viability in farming, is gaining attention in agriculture. Similarly, salicylic acid (SA) has emerged as a potential chemical inducer to enhance plant metabolic activities, stress tolerance, and crop yield in the face of climate change. Our two-year field study aimed to assess the impact of varying rates of nano NPK fertilization and SA chemigation on the phytochemical properties, nutritional quality, and fruit attributes of processing tomatoes (Solanum Lycopersicum L., cv. BHN685), relative to conventional fertilization. Employing a two-factorial drip-irrigated plasticulture setup in a completely randomized design, we tested four levels of nano NPK (0, 40, 80, and 120 kg/ha) and two levels of SA (0 vs. 0.3%), each replicated four times. Results showed that tomato fruits subjected to SA chemigation with nano-NPK fertilization exhibited a significant increase in concentration of phytochemicals. Notably, vitamin-A, vitamin-C, lycopene, β-carotene, polyphenol, flavonoid, anthocyanin, and antioxidant capacity displayed substantial increases ranging from 2.5% to 51.2% compared to the control. Particularly noteworthy were the remarkable enhancements in flavonoid and anthocyanin concentrations, registering at 50% and 51.2%, respectively. Conversely, application of nano NPK alone led to discernible increases solely in flavonoid and anthocyanin concentrations, accompanied by decreases in other phytochemicals. Further analysis underscored the synergistic benefits of SA and nano-NPK, resulting in superior color, taste, and phytochemical richness of tomato fruits. K-means cluster analysis corroborated the efficacy of the SA with nano NPK (120 kg/ha) treatment in eliciting optimal fruit characteristics. Moreover, quality assessment revealed the superiority of the SA nano-NPK (120 kg/ha) treatment, with a quality index of 0.61 compared to the control's 0.47, indicative of its superior attributes. Additionally, the nutritional quality index demonstrated a gradual increase in nutrient enrichment across treatments, with the SA and nano NPK (120 kg/ha) combination yielding the highest score. In conclusion, our study highlights the pivotal role of SA in conjunction with nano NPK (120 kg/ha) in enhancing tomato phytochemical content and overall fruit quality. These findings bear significant implications for optimizing horticultural practices and promoting sustainable food production endeavors.
Speakers
TH

Thomas Harker

Research Assosiate, The Ohio State University
Thomas Harker currently holds a research associate position specializing in horticultural and specialty crops at the Ohio State University South Centers. With an extensive career spanning over 25 years, he has been deeply immersed in the exploration and enhancement of various crops... Read More →
Co-authors
AR

Arifur Rahman

The Ohio State University South Centers
NA
BB

Brad Bergefurd

Brandt Discovery
NA
EB

Ed Brown

The Ohio State University Extension Athens County
NA
RI

Rafiq Islam

The Ohio State University South Centers
NA
WL

Wayne Lewis

The Ohio State University South Centers
NA
ZG

Zhenhao Guan

The Ohio State University South Centers
NA
Friday September 27, 2024 3:00pm - 3:15pm HST
Lehua Suite

3:00pm HST

POM 4 - Does the Utah Model Still Work in Utah? Evaluation of Existing Phenological Models for Tart Cherry in a Changing Climate
Friday September 27, 2024 3:00pm - 3:15pm HST
Phenological models use local temperature data to predict spring flower bud development and guide management decisions in temperate fruit crops. In high elevation continental regions such as the U.S. Intermountain West, changing climate brings more extreme temperature variability resulting in increased risk of spring freeze damage. We evaluated bloom dates of tart cherry (Prunus cerasus L. ‘Montmorency’) in a high elevation continental climate (1327 to 1484 m elevation, Utah) to test the validity of 50-year-old phenological models under current climatic conditions. Mature commercial tart cherry blocks were selected in proximity to existing weather stations (climate.usu.edu, FGNet). Bud stages were observed weekly in April and May of 2019 through 2023 with 3 to 8 locations monitored per year. Observed stages were compared to Utah Standard and Modified prediction models. Prediction error varied with year and stage of development, where 2023 bloom was on average 3 days earlier than predicted, compared to 2020 when bloom was 6 days later than predicted. Modern weather stations provide more detailed climatic data (hourly temperature, light, humidity, wind speed), and the opportunity to refine and improve existing models. Improved model reliability would provide better decision support for increasingly expensive freeze protection measures.
Speakers
JM

Josette Moon

Utah State University
Co-authors
BB

Brent Black

Utah State University
NA
MS

Melanie Stock

Utah State University
NA
Friday September 27, 2024 3:00pm - 3:15pm HST
South Pacific 3

3:15pm HST

CE 9 - Optimization of Irrigation Based on Substrate Type for Tomato Production in the Dutch Bucket Hydroponic System
Friday September 27, 2024 3:15pm - 3:30pm HST
Dutch bucket hydroponic systems are used for high-wire crop production such as tomatoes, cucumbers, or peppers, and are typically filled with perlite as a substrate. Through past research, our group identified pine bark and wood fiber as sustainable alternative substrates for high-wire tomato production. Typically, greenhouse tomato growers utilize leachate-based or timed irrigation; however, the use of a water content sensor could precisely identify the irrigation set-point for different substrates, potentially saving water and fertilizers. This study aimed to optimize the irrigation rate for greenhouse tomato ('Favorita F1') production in the Dutch bucket hydroponic system using a soil water content sensor. Three types of substrates (perlite, pine bark, and wood fiber-coir mix (60:40)) and four different gravimetric water contents (100%, 120%, 140%, and 160%) were considered. The experiment was conducted with three replications in a completely randomized design, with the irrigation treatments under the perlite substrate serving as the control. Physical parameters, such as the number of leaves and plant height, were significantly higher in the wood fiber-coir mix and pine bark at 160% irrigation, and lowest under perlite at 100% water content. However, there was no significant difference among the treatments for the number of flower (fruit) clusters. The plant leaf area measurements indicated better vegetative growth with wood fiber-coir mix at 160% water content, whereas pine bark at 160% water content resulted in a higher yield and better fruit quality. In contrast, phytochemicals such as Brix, vitamin C, titratable acidity, lycopene, beta-carotene, and phenolic compounds were significantly higher in the organic substrates (pine bark and wood fiber) with low water content (100% to 120%) and lower in perlite with high water content (140% to 160%). The highest and lowest concentrations of phytochemicals varied between 13% to 67%. There was no significant difference among the treatments (substrates and water contents) in terms of tissue mineral analysis. In general, plants grown in wood fiber-coir mix treatments required 28% and 51% less irrigation compared to those in pine bark and perlite treatments, respectively. Plants grown in organic substrates require less water, and the yield quantity and quality are either similar to or higher than those in perlite. Out of the organic substrates, wood fiber-coir mix can be used in Dutch bucket systems to conserve water and nutrients, enhancing yield quantity and quality, and thereby achieving environmental sustainability.
Speakers
MC

Milon Chowdhury

The Ohio State University
Co-authors
JM

Joanna Moine

The Ohio State University
NA
US

Uttara Samarakoon

The Ohio State University
Friday September 27, 2024 3:15pm - 3:30pm HST
Nautilus

3:15pm HST

FRBR 2 - Evaluation of Small Fruit Germplasm at the North Willamette Research and Extension Center
Friday September 27, 2024 3:15pm - 3:30pm HST
Since the 1920’s, Oregon State University (OSU) and the United States Department of Agriculture (USDA) Horticultural Crops Production and Genetic Improvement Research Unit have cooperated in the public breeding and development of small fruit cultivars to support Pacific Northwest (PNW) production. Together, the PNW states of Oregon and Washington have significant berry production with 152,407 metric tons of blueberry (Vaccinium spp.), 24,494 metric tons of red and black raspberry (Rubus idaeus; R. occidentalis), 9,525 metric tons of blackberry (Rubus spp.), and 6,804 metric tons of strawberry (Fragaria x ananassa) in 2022. Processed berries are the primary regional market, with fresh market production a lesser but still important driver for small farms. To continue to improve regional production of high-quality fruit, cultivar development has been a top tier research priority for PNW berry commodity commissions over the past decade. The cooperative breeding program has a continual germplasm improvement cycle that includes plant material in all stages of development, from seedlings, observational and replicated field trials, grower trials, and cultivar releases. After seedling evaluation, promising advanced selections of strawberry, blueberry, blackberry, red raspberry, and black raspberry crops are assessed at the OSU North Willamette Research and Extension Center in Aurora, Oregon. The USDA and OSU cooperative breeding program, in collaboration with Washington State University, has a uniquely strong focus on developing machine harvestable small fruit cultivars. Over 20 cultivars have been released with a value to PNW industries of over $450 million in the last ten years. ‘Tillamook’ strawberry, and ‘Black Diamond’ and ‘Columbia Star’ blackberry lead the acreage in Oregon and were developed by the program. More than 50 berry cultivars have been released since 1942 exclusively by the USDA with another 16 jointly-released with other agricultural universities and international corporations. This presentation will outline the cooperative breeding framework, discuss breeding priorities, and highlight new and upcoming cultivar releases.
Speakers
PJ

Patrick Jones

Oregon State University
Co-authors
AD

Amanda Davis

Oregon State University
NA
JL

Jungmin Lee

USDA-ARS
NA
MP

Mary Peterson

USDA-ARS
NA
SL

Scott Lukas

Oregon State University
NA
TM

Ted Mackey

USDA-ARS
NA
ZW

Zachary Wiegand

Oregon State University
NA
Friday September 27, 2024 3:15pm - 3:30pm HST
Kahili

3:15pm HST

GG 5 - Comparative Analyses of Tissue-Specific Transcriptome Responses to Salt Stress in Lettuce Roots and Leaves
Friday September 27, 2024 3:15pm - 3:30pm HST
Lettuce is one of the most important leafy vegetable crops world-wide. Salt stress adversely affects lettuce production, leading to considerable yield losses. Understanding the molecular mechanisms underlying the salt stress response is essential for breeding and development of lettuce cultivars with improved salt tolerance. Thus, the objective of this research was to identify differentially expressed genes (DEGs) in lettuce root and leaf tissues under salt stress and non-salt stress conditions. We have compared two salt-stress tolerant and two salt-sensitive accessions from crisphead and leaf horticultural types. Differential gene expression was compared between salt-tolerant and salt-sensitive accessions from the same horticultural type to minimize the effect of horticultural types on the comparison. In the root samples of the salt-tolerant accessions, we identified 3,789 and 4,022 DEGs, while for the salt-sensitive accessions 9,030 and 9,945 DEGs were identified, for the crisphead and leaf types, respectively. In leaf tissues, we observed 5,683 and 9,445 DEGs in the salt-tolerant accessions and 5,836 and 10,172 DEGs in the sensitive accessions, respectively, for the crisphead and leaf types. Thus, the number of DEGs was higher in sensitive accessions of both root and leaf tissues, with a notably greater disparity in root tissues. Functional annotations of the DEGs indicated stress response as a common biological process in both root and leaf tissues. Protein phosphatase inhibitor and peroxidase were the most significantly enriched molecular function terms in roots, while chaperone and glycosyltranferase molecular function terms were most significantly enriched in leaves. Gene Ontology (GO) enrichment analysis determined that genes related to the organic substance biosynthetic process were most significantly enriched in roots, while genes related to photosynthesis, response to light stimulus, chlorophyll binding and regulation of the jasmonic acid-mediated signaling pathway were significantly enriched in leaves. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that plant hormone signal transduction, biosynthesis of secondary metabolites, and the MAPK signaling pathway were significantly enriched terms in both root and leaf tissues, while cysteine and methionine metabolism terms were most significantly enriched in roots and photosynthesis was most significantly enriched in leaves. Identification of the salt-stress responsive genes and the results on their expression patterns in salt-tolerant vs salt-sensitive cultivars obtained in the present study open the door for further functional analysis of these genes and their utilization in improving salt-stress tolerance in lettuce.
Speakers
MD

Modan Das

USDA-ARS
Co-authors
BM

Beiquan Mou

USDA-ARS
NA
IS

Ivan Simko

USDA-ARS
NA
Friday September 27, 2024 3:15pm - 3:30pm HST
Coral 1

3:15pm HST

LOCSY - Food Policy and Food Security
Friday September 27, 2024 3:15pm - 3:30pm HST
Food policy and food security are two areas crucial to the success and health of many around the world. They take the commitment, hard work, and perseverance of many stakeholders from producer to consumer to legislation. Furthermore, as the population of the world continues to expand, an increase in production does not necessarily correlate to increased accessibility to healthy quality produce, building or support of local food systems or communities. Although methods can be implemented on a small community level, there are many opportunities to create more hospitable environments for horticultural production in Oklahoma. This leads to the current project to evaluate the state of the state’s food policy and plans for food security in hopes of providing strategies to best advise legislation and to ease barriers local producers experience through their advocacy. Additionally, as extenuating factors play into food security, it is important to factor in other areas of concern in policy and available resources, such as economics and regional factors. This presentation follows the research and analysis of the master’s project. Food policy is essential in supporting local producers, whether through resources, addressing barriers, or creating a pro-agricultural environment. Food policy also lead into many additional factors such as accessibility, especially for underserved populations, and the creation of healthier, more aware, and sustainable communities.
Speakers
SD

Sophia Darrow

Oklahoma State University
Co-authors
JM

Justin Moss

Oklahoma State University
NA
Friday September 27, 2024 3:15pm - 3:30pm HST
South Pacific 1

3:15pm HST

O/LT 3 - Cool-season Turfgrass Biomass and Ecosystem CO2 Flux as Affected by Fertilization and Irrigation
Friday September 27, 2024 3:15pm - 3:30pm HST
Concerns about the environmental impacts of lawns, including a high climate footprint, can pose challenges to the acceptance of natural turfgrasses. There are limited assessments of how to enhance turfgrass carbon sequestration and reduce management inputs in turfgrass systems in the northwest U.S. The goal of this study was to evaluate how fertilization and irrigation management can affect the ability of mixed cool-season turfgrass stands to sequester carbon. Annual rates of 0 and 196 kg N ha−1 were evaluated in the fertilization trial, while a non-irrigated control and 0.6 cm of precipitation applied four times per week in the summer months were compared in the irrigation trial. A portable clear chamber with a CO2 gas analyzer was used to measure CO2 fluxes. Grass clippings were collected from each plot to measure dry weight and subsequently returned to their respective plots. Clipping data were summarized as annual clipping production rates. Turfgrass standing biomass was sampled in 2021 and 2022 after summer stress and separated into aboveground (verdure) and belowground (thatch and roots) biomass. Our results indicated that the annual fertilization rate of 196 N ha−1 significantly increased photosynthesis in cool-season turfgrass in the winter and early spring compared to the unfertilized control. Fertilization also increased the net ecosystem exchange (NEE) rate in the winter, but the increases in NEE were less frequently observed than in the photosynthetic rate. Moreover, higher respiration rates were occasionally observed with the fertilization treatment. In contrast, fertilization had little to no effect on NEE, photosynthesis, and ecosystem respiration rates during the summer. Fertilization resulted in higher annual clipping yield, whereas there were no statistical differences between fertilization and no fertilization treatments in above- or below-ground biomass. In the irrigation study, the growth of turfgrass without irrigation ceased during summer as evidenced by reduced photosynthetic rates that were close to 0. Summer irrigation also stimulated ecosystem respiration which offset the benefits of enhanced photosynthetic rates, suggesting that further research is needed to identify the optimum irrigation practice for enhancing net CO2 assimilation. Irrigation produced greater annual clipping production in 2021 but had no effect in 2022. Irrigation was also shown to significantly increase aboveground biomass, but belowground biomass was not affected by irrigation. These results provided a better understanding of cool-season turfgrass growth in the Pacific Northwest U.S. so that cultural practices can be refined for more climate-friendly turfgrass management.
Speakers
RW

Ruying Wang

Oregon State University
Co-authors
AK

Alec Kowalewski

Oregon State University
NA
CM

Clint Mattox

USDA-ARS
NA
EB

Emily Braithwaite

Oregon State University
NA
ZH

Zachary Hamilton

Oregon State University
NA
Friday September 27, 2024 3:15pm - 3:30pm HST
South Pacific 2

3:15pm HST

PNM 3 - Alternative Fertilizer Methods For Palm Trees
Friday September 27, 2024 3:15pm - 3:30pm HST
Lack of water holding and cation exchange capacity severely limit fertilizer application methods for new palm tree transplants in sandy soils in S. Florida. Typically, palm trees are fertilized using an 8-2-12 4 granular fertilizer but with little rooting to enhance fertilizer capture and no soil solution to improve nutrient uptake, establishment may be slow. Alternative fertilizers, including palm tree injection, were evaluated to determine the best method to improve palm tree establishment under these conditions. A research trial was conducted using Christmas Palms (Adonidia merrillii) that were established on sandy soils with less than 2% organic matter. After planting, palms were not fertilized for six months. Palm trees were treated with the following fertilizers: 1) 8-2-12 4 (PS), 2) 0-0-22 4(KM) 3) PHOSPHO-jet PALM-jet injection (PJ) 4) PHOSPHO-jet PALM-jet apical meristem drench (AM) and 6) “Gator Grip” (GG) fertilizer pouch directed at the apical meristem. Visual quality and drone imagery were used to assess palm health. Volumetric water content (VWC) was determined at three different depths and root growth was captured using a mini-rhizotron. Six months after the initial treatment application, treatment differences were not visually apparent and VWC was below 10% for the majority of measurements captured at all depths. Rooting data at this stage was minimal. Palm trees may grow very slowly and under these environmental conditions, it may take the palm over a year to replace an entire crown. Therefore, yearly updates will be presented for this three-year trial to best determine which treatment provides the best solution to establish transplanted palms in the landscape and maintain palm health.
Speakers
MM

mica mcmillan

University of Florida
Co-authors
KW

Karen Williams

University of Florida
NA
NF

Naomi Franklin

University of Florida
NA
Friday September 27, 2024 3:15pm - 3:30pm HST
Lehua Suite

3:15pm HST

POM 4 - A Mobile Cartographer System to Measure Tree Growth Within Tart Cherry Orchards
Friday September 27, 2024 3:15pm - 3:30pm HST
Temperate orchard sites have highly variable soils that contribute to uneven tree growth, providing a unique setting for precision management efforts. Precision management seeks to map spatial variability and implement variable rate management to optimize inputs. The objective of this study was to develop a platform for simultaneous measurement of tree growth and size to facilitate the enhancement of precision management practices in tart cherry (Prunus cerasus) orchards. Measurements included: canopy light interception; canopy height, volume, and width; and trunk cross sectional area (TCSA). Light interception (ceptometry) was by 15 30-cm line quantum sensors recording PAR at 0.6-second intervals, positioned on a UTV-mounted boom that passed under the canopy. Light interception was calculated based on data from a reference PAR sensor placed outside the orchard. Canopy height, width and volume of individual trees were measured using a side-scan LiDAR system mounted to the same UTV that generated point-cloud maps of each orchard row. These canopy measurements were then compared to point-cloud maps generated from aerial visual imaging (UAV). TCSA was estimated using a stereovision depth camera that captured paired visual spectrum (RGB) and point-cloud images, that were then aligned and segmented for individual tree trunks. Using pixel depth data, trunk widths for individual trees were estimated. The platform and associated sensors were used to map four commercial tart cherry orchard blocks (8-10 ha) located near Santaquin, Utah, USA, during the 2023 (ceptometry and UAV, only) and 2024 seasons at 2-week intervals. During the 2023 season, 8 ceptometry maps were generated with corresponding UAV-based maps. Side scan lidar data for 1 map of canopy height, width, and volume were collected in each of the 4 orchards, along with data for 1 TCSA map. Preliminary analysis shows strong spatial agreement among mapping techniques, indicating that the technologies are well suited to precision orchard management. Data for 2024 will also be presented, with multi-season tree growth analysis.
Speakers
avatar for Brent Black

Brent Black

Utah State University
NA
Co-authors
BS

Bailey Shaffer

Utah State University
NA
GC

Grant Cardon

Utah State University
NA
KW

Kurt Wedegaertnerr

Utah State University
Friday September 27, 2024 3:15pm - 3:30pm HST
South Pacific 3

3:30pm HST

CE 9 - The Secondary Metabolite Production and Growth Responses of Cannabis to Thigmomorphogenesis in a Controlled Environment
Friday September 27, 2024 3:30pm - 3:45pm HST
As legalization continues to change the cannabis industry, we see an influx of creative innovation, funding, and research as more entities enter the field. The two innovative growing management investigated in this study were Mechanical Vibration Training (MVT) and High Stress Training (HST). MVT was carried out using a grid exposing the plants to 200 Hz vibration, and HST is a practice that involves damaging the vascular bundles, pith, and cortex of the main stem while leaving the epidermis intact. MVT is a newer technique still in development, as Thigmo-priming has been shown to change plant morphology and chemistry and even increase the speed and magnitude of future stress responses. Many industry leaders claim that the advantages of using HST include higher canopy, increased biomass and cannabinoid concentrations, and more effective IPM strategies. However, studies validating these claims are still being determined. This study aims to compare each growing management under the overall category of Thigmomorphogenesis or mechanostimulation against control (no artificial mechanical stimulation) and tease out any synergism between the treatments. We hypothesize that applying mechanostimulation to cannabis plants will enhance their growth and increase secondary metabolite production. The environment-controlled growth units housed the treatments consisted of 1-Control, 2-MVT, 3-HST, and 4-MVT HST. Each growth unit contained five-gallon fabric pots with a single Suver Haze plant. An amended coco coir substrate was used with a water-soluble nutrient solution, and optimal growing conditions, including lighting, were maintained equally in all environment-controlled growth units. Weekly plant parameters included stem diameter, plant height, NDVI, chlorophyll concentration, and photosynthetic efficiency. After-harvest parameters included above/below ground biomass, yield mass, bucked biomass, trichome density, and cannabinoid levels. Morphological and numerical differences between treatments indicated the potential for a shorter, more efficient growth cycle with higher cannabinoid levels. Further testing is currently underway.
Speakers
avatar for Jose Leme

Jose Leme

Assistant Professor, Southern Illinois University
The Cannabis Biology and Cultivation Systems lab focuses on areas of controlled environment agriculture, plant stress, secondary metabolites, nutraceutical/pharmaceutical biology, and growing practices. The research team aims to determine how to leverage environmental controls (light... Read More →
Co-authors
AA

Aldwin Anterola

Southern Illinois University
NA
DO

Dila Ozev

Southern Illinois University
NA
GS

Gorman Saunders

Southern Illinois University
NA
JW

Jennifer Weber

Southern Illinois University
NA
KG

Karla Gage

Southern Illinois University
NA
SS

Shiksha Sharma

Southern Illinois University
NA
Friday September 27, 2024 3:30pm - 3:45pm HST
Nautilus

3:30pm HST

FRBR 2 - Developing a Genomic Framework for Selection of Fruit Attributes in Cold Climate Interspecific Grapes (Vitis Spp.)
Friday September 27, 2024 3:30pm - 3:45pm HST
Hybrid grapevines (Vitis spp.) grown in cold climate regions have fruit chemistries which do not adhere to the standard ranges of European wine grapes (Vitis vinifera L.) that many consumers may be accustomed to. The variation in fruit chemistry observed in hybrid grapevines is driven by a combination of genetics of parent material, which often builds on wild Vitis species, and the environmental conditions of production, which are often characterized by low heat accumulation and limited duration of growing season. Characterizing the genetic basis of fruit attributes enables breeders to understand and improve the relative quality of interspecific grapevines for future cultivar development. To address this knowledge gap for breeders, an incomplete diallel population of interspecific hybrid grapevines was assessed over a period of three years. Fruit chemistry (total soluble solids, pH, total acidity, glucose, fructose, malic acid, tartaric acid, citric acid, and yeast assimilable nitrogen content) and berry mass were examined at three distinct time points within each growing season to yield a total of nine phenotyping events. Best linear unbiased predictors (BLUPs) calculated from multi-year phenotype data were then interrogated via GWAS analysis to identify significant marker-trait associations. Chromosomes 16, 6, and 17 were noted to have the highest number of associations observed. To further understand the specificity of observed loci, gene annotation was conducted to reveal several important genes potentially related to the phenotypes. Due to the quantitative nature of fruit attributes, genomic selection strategies were explored to assess their accuracy for improving population performance in a systematic manner. Cumulatively, this analysis provides important information regarding the role of genetics in major fruit traits of interspecific cold hardy grapevines, regions of interest for fine mapping, and strategies for genomic selection. These analyses contribute towards the goals of improving breeding efficiency and selection accuracy to reduce generation timeline in grapevines.
Speakers
avatar for Venkateswara Rao Kadium

Venkateswara Rao Kadium

Montana State University
Co-authors
AS

Andrej Svyantek

Montana State University
NA
CA

Collin Auwarter

North Dakota State University
NA
JS

John Stenger

North Dakota State University
NA
RP

Ramesh Pilli

North Dakota State University
NA
XL

Xuehui Li

North Dakota State University
NA
ZW

Zhuoyu Wang

Montana State University
NA
Friday September 27, 2024 3:30pm - 3:45pm HST
Kahili

3:30pm HST

GG 5 - QTL Mapping Of Horticulturally Important Plant Architectural Traits In Cucumber (Cucumis sativus L.)
Friday September 27, 2024 3:30pm - 3:45pm HST
Cucumber (Cucumis sativus L.) is an economically important vegetable crop cultivated worldwide. Plant architectural traits, such as lateral branch number (LBN), vine length (VL), number of nodes (NN) and internode length (IL), may directly influence production practices, plant performances, fruit yield and quality. Despite their importance, investigation on the genetic basis of these traits in cucumber is limited. In this study, we conducted QTL mapping for VL, NN, IL and LBN using bi-parental F2, F2-derived F3 and recombinant inbred line (RIL) populations. There are significant positive correlations between LBN, VL and NN. Estimated board-sense heritability using entry-mean basis of the RIL population was high, ranging from 0.66 to 0.84. Two linkage maps were developed through genotyping-by-sequencing of 140 F2 individuals and Diversity Arrays Technology (DArTag) SNP genotyping of 135 RIL, containing 1912 and 334 SNP loci in seven linkage groups and spanning 1077 and 948 cM, respectively. QTL mapping analysis detected a total of 79 QTLs associated with the four traits in six environments or populations. Based on their physical locations, 66 QTLs were distributed in ten QTL clusters harboring four major-effect and six minor-effect QTLs. Each of the major- and minor-effect QTLs was supported by consistent and reproducible detection from at least three environments. Notably, major-effect QTLs for VL, NN and LBN were co-localized in two genomic regions on Chr1 (3.73 Mbp) and Chr6 (3.78 Mbp), and the major-effect QTL for IL was mapped in a 3.98-Mbp region on Chr5. These findings provide a framework for dissecting the genetic architecture of these complex traits, and valuable genetic information for cucumber breeders to employ molecular-assisted breeding approaches and develop improved varieties with enhanced productivity.
Speakers
TN

Thi Nguyen

Research Assistant, University of Wisconsin- Madison
Co-authors
YY

Yassine Yahia

University of Wisconsin-Madison
NA
YW

Yiqun Weng

University of Wisconsin-Madison
NA
Friday September 27, 2024 3:30pm - 3:45pm HST
Coral 1

3:30pm HST

LOCSY - Sustainable Small Plot Farming and Entrepreneurship Training Program
Friday September 27, 2024 3:30pm - 3:45pm HST
In response to growing concerns of food insecurity within our communities in the big bend region of Florida, Tallahassee State College in partnership with the City of Tallahassee established a training program to empower emerging farmers. This innovative program equips participants with the necessary skills and knowledge to efficiently and sustainably cultivate fruits and vegetables using organic and permaculture practices. The primary aim is to enable individuals to utilize small plots of land effectively, thereby fostering self-sufficiency and contributing to the local food community. The program was conceived as a direct countermeasure to the challenges of food scarcity and the underutilization of available land for food production. By focusing on small-scale, sustainable farming, the initiative seeks to transform even limited spaces into productive market gardens. This approach not only addresses immediate food production needs but also promotes long-term environmental stewardship through sustainable agricultural practices. A distinctive feature of the program is its partnership with local farms, which provides a practical, hands-on learning environment for participants. These collaborations are vital for the integration of theoretical knowledge with real-world farming experiences, enhancing the learning process. Historically, the program supported learners through paid apprenticeships, allowing them to earn while they learn. Since its launch, various sponsors have funded the program, offering scholarships that eliminate cost barriers. Presently, it’s supported by a USDA AFRI Agricultural Workforce Training grant, which includes equipment stipends and industry-recognized certifications. These additions aim to further support and broaden the participants' success in the agricultural sector. The certifications serve as a formal acknowledgment of their technical proficiency and a steppingstone towards further career opportunities in agriculture. Through its comprehensive curriculum, this program not only teaches participants how to grow food but also instills entrepreneurial skills necessary for starting and managing a market garden. This dual focus ensures that graduates are well-prepared to either enter the agriculture industry or start their own farming ventures. Ultimately, this program strives to create a network of skilled, knowledgeable farmers who are capable of contributing to their communities by increasing local food production and enhancing food security. By doing so, it supports not only the participants and their families but also enriches the broader local food ecosystem. The ongoing success of the program underscores its significance as a vital educational resource in the fight against food insecurity through sustainable agriculture.
Speakers
AH

Alexis Howard

Insturction and Project Coordinator, Tallahassee State College
Alexis is an environmental professional with a focus on agriculture education and entrepreneurship training. After earning a bachelor’s degree in Environmental Science and Policy from the Florida State University (FSU), Alexis acquired a job as a Program Assistant at Tallahassee... Read More →
Friday September 27, 2024 3:30pm - 3:45pm HST
South Pacific 1

3:30pm HST

O/LT 3 - The 2023 Arkansas Diamond Plant Evaluation Trials
Friday September 27, 2024 3:30pm - 3:45pm HST
Arkansas’ research-backed plant assessment initiative known as "Arkansas Diamonds" aims to educate local gardeners on annual bedding plants that consistently thrive in Arkansas's climate. Moreover, it serves to bolster local growers and independent garden centers within the state. Facilitated by the Arkansas Green Industry Association (ARGIA) and the University of Arkansas System Division of Agriculture (UADA), this collaborative effort engages county agents across Arkansas in annual demonstration plots. In 2023, thirty county agents partook in the statewide evaluation of four annual plant species. Each agent received nine replicants of each species and conducted monthly measurements of height, width, flower quality, and overall health. These findings, integral to the selection process, contribute to designating certain plants as "Arkansas Diamonds," signifying their suitability for the state's gardens and green industry. After evaluations, the selected plants are grown by ARGIA members and marketed on a statewide basis to encourage home gardeners and the landscape industry to incorporate these plants into their home landscapes and support the local green industry and independent garden center within the state.
Speakers
AB

Anthony Bowden

University of Arkansas
Co-authors
RF

Randy Forst

University of Arkansas
NA
Friday September 27, 2024 3:30pm - 3:45pm HST
South Pacific 2

3:30pm HST

POM 4 - Enhancing Uniformity in Tart Cherry Orchards Through Precision Management and Variable Rate Fertilization
Friday September 27, 2024 3:30pm - 3:45pm HST
Tart cherry (Prunus cerasus) orchard sites are often chosen for favorable microclimates, and consequently exhibit highly diverse soil conditions that result in non-uniform tree growth and yield potential. There is increasing interest in utilizing precision management techniques to map tree vigor and implement variable rate management to optimize inputs and enhance uniformity. The objective of this study was to assess the variability of soil and canopy characteristics and implement prescription fertilizer rates based on the mapped variability. The study was conducted on four mature (18-22 years) commercial tart cherry orchard blocks (8-10 ha) located near Santaquin, Utah, USA. Soil variability maps for each orchard were generated through soil sampling, guided by surveying apparent electrical conductivity (ECa) using an electromagnetic induction meter. Spatial variability in tree vigor was quantified using satellite imagery provided by Simplot Smart Farm® Permanent Crop Analysis. Prescription fertilizer rates, derived from the variability maps, were applied to each block in the spring/summer of 2023 and 2024, which included granular fertilizer applied as a single application or as split applications based on each prescription map. Tree response to the prescription treatments were monitored every two weeks using a novel platform capable of mapping plant growth parameters including canopy height, volume, width, and density; and trunk cross sectional area (TCSA). By monitoring growth parameters within this timeframe, we were able to comprehensively evaluate within-seasonal fluctuations in growth. Soil sampling revealed significant correlations between ECa and soil texture. Preliminary results indicate significant within-orchard variations in mid-season tree vigor, that are also correlated with long-term growth characteristics (canopy size and density). Both long-term and short-term growth measures are also closely correlated with soil ECa (i.e. texture). The effect of variable fertilizer application within this soil texture variability will be discussed, offering insight into the effectiveness of precision management techniques in mitigating variability within tart cherry orchards.
Speakers
avatar for Kurt Wedegaertner

Kurt Wedegaertner

Utah State University
Co-authors
BS

Bailey Shaffer

Utah State University
NA
BB

Brent Black

Utah State University
NA
GC

Grant Cardon

Utah State University
NA
Friday September 27, 2024 3:30pm - 3:45pm HST
South Pacific 3

3:45pm HST

CE 9 - Simulated Climate-change-related Environmental Stressors Can Alter the Yield and Metabolomics of Tomato
Friday September 27, 2024 3:45pm - 4:00pm HST
Climate change challenges all aspects of food production, including standard greenhouse products, such as tomatoes. The cause of climate change can be directly attributed to the rise in carbon dioxide (CO2) levels, leading to increased temperatures and drought severity. Tomatoes are the most produced fruit crop globally, and in addition to their economic benefits contain several vitamins and minerals essential for human health. The objective of this study was to assess the multi-variable effects of simulated climate change on tomato plants by investigating the combination of elevated CO2 (800 ppm vs 400 ppm), increased temperature (28℃ vs 21℃), and water deficit stress (20% decrease from control) across three development stages: juvenile, anthesis, and fully mature tomato. ‘Sweet ‘N’ Neat Scarlet’ tomatoes (Solanum lycopersicum) were grown in four plant growth chambers in a 2 x 2 x 2 factorial design with four replications. Quality parameters included photosynthetic efficiency, growth index, dry weight, flower number, fruit number, and fruit size. Inductively coupled plasma mass spectrometry (ICP-MS) and oxygen radical absorbance capacity (ORAC) analyses were measured at each of the three stages when applicable. Preliminary data suggests that higher temperatures and CO2 increase (p
Speakers
MV

Marlo Vandiver

West Virginia University
Co-authors
JT

Janet Tou

West Virginia University
NA
NW

Nicole Waterland

West Virginia University
NA
YM

Youyoun Moon

West Virginia University
NA
Friday September 27, 2024 3:45pm - 4:00pm HST
Nautilus

3:45pm HST

FRBR 2 - U.S. Peach Production and Breeding Overview
Friday September 27, 2024 3:45pm - 4:00pm HST
Peach is an introduced crop with a relatively short production and breeding history in the U.S. The peach industries have been facing declines and challenges in both production and breeding activities over the past decades. Understanding of the statuses and issues facilitates gaining insights and finding solutions. This presentation is to provide an overview of U.S. peach production and breeding, including trends, issues, and prospects. Both U.S. peach acreage and production are declining, but market values increasing. Public peach breeding programs were established at the early time and helped establish considerable production in many states. But most of them have been terminated, phased out, or de-emphasized, largely due to declining production and economic impact. Taken into consideration all factors, visionary peach horticulture research and breeding solutions for some cost-related and yield-limiting production issues are essential for profitable and sustainable peach production in the future.
Speakers
Friday September 27, 2024 3:45pm - 4:00pm HST
Kahili

3:45pm HST

GG 5 - Variation for Non-Acclimated and Acclimated Heat Tolerance Among Potato Germplasm: Indication of Separate Genetic Control
Friday September 27, 2024 3:45pm - 4:00pm HST
Several studies have documented variation in potato germplasm for heat tolerance of leaf tissue. Most researchers have relied on screening for heat stress by exposing excised leaf tissue (grown under non-stress condition) to a short-term (minutes-hours) of acute heat stress (37-55C). It is well known that plants vary in their ability to acclimate to heat stress know as priming. This priming can enable plant to survive subsequent temperatures that are lethal to plants grown under non-stress condition. Our recent studies show that potato plants under prolonged heat stress (35/25C, day/night, for 3-5 weeks) newly developed leaves (acclimated) can maintain health under heat stress by modifying anatomy and physiology. These results show that potato plants have the ability to acclimate to heat stress that results in increased heat tolerance. In the present study, we screened to potato germplasm for heat tolerance of leaf tissue before and after heat acclimation. Ion leakage after exposure of excised leaf tissue to 50C, was used as a screening assay and a reduction in this leakage was used to assess the heat acclimation ability. Wide variety of potato germplasm including commercial cultivars and accessions of various wild species were screened. Our result show significant genotypic variations in acclimated and non-acclimated heat tolerance. Furthermore, the heat acclimation ability appears to be independent of non- acclimated heat tolerance. For example, certain clones of the species Solanum commersonnii had similar non-acclimated heat tolerance but large variation in acclimated tolerance was found among various clones of this species. Similar results were obtained for different clones of Solanum microdontum and Solanum kurtzianum. As expected, the cultivars Zarewo, DTO and Papa Cacho were found to have higher non-acclimated heat tolerance than the others, but Papa Cacho had the highest heat acclimation ability. Our results suggest that non-acclimated heat tolerance and acclimated heat tolerance are under separate genetic control and that selection for both non-acclimated and acclimated heat tolerance may be useful for successful breeding for heat tolerance of potato leaf tissue.
Speakers
JP

Jiwan Palta

UW Madison
Co-authors
AD

Alfonso DelRio

University of Wisconsin Madison
NA
JB

John Bamberg

University of Wisconsin Madison
NA
JS

Justin Schabow

University of Florida
NA
Friday September 27, 2024 3:45pm - 4:00pm HST
Coral 1

3:45pm HST

POM 4 - Tree temperature prediction to improve chill accumulation estimation in cherry under climate change
Friday September 27, 2024 3:45pm - 4:00pm HST
Timing application of dormancy breaking products is essential for adequate bloom and yield in cherry. Available temperature-based chill accumulation models often fail to predict correct spray timing, particularly during years with unusual temperature patterns recently driven by climate change. One potential cause for the unreliability of the current models is their dependence on a single climatic variable, air temperature, to estimate the impact of weather on tree physiological processes. We hypothesized that using tree temperature, rather than air temperature, will increase the accuracy in predicting chill accumulation, especially in warm and sunny winters. Hence, our objective was to develop a framework to predict cherry tree temperature based on easily available environmental data. For three consecutive seasons and in three commercial cherry orchards across California, including the southernmost US cherry production region, we measured main climatic parameters at half hour intervals. At the same time, we monitored tree temperature with T-type thermocouples inserted below the bark of main branches. We developed predictions of tree temperature as a function of meteorological variables obtained from public weather stations using generalized additive models. Trees were, on average, 10 ºF warmer than the air during clear days, with differences being up to 20-25 ºF. Tree chill accumulation was about 8-12 chill portions lower than air chill accumulation. The difference was year- and site-specific, reflecting the importance of including diverse environmental parameters to estimate chill accumulation precisely. The ‘TreeChill model’ predicts tree temperature based only on environmental parameters easily achievable from public weather stations with a coefficient of determination of 0.956 resulting in only 0.4 chill portions difference between measured and predicted tree chill. This model will enable growers to implement tree temperature in their management decisions, including dormancy breaking agent applications, cultivar selection, pest control etc, increasing California cherry industry resilience to climate change. In the future, we plan to adapt the model to different crops and locations.
Speakers Co-authors
AS

Aileen Salas

UC Davis
NA
AP

Amrit Pokhrel

UC Davis
NA
DR

Daniel Ruiz

UC Davis
NA
EL

Emilio Laca

UC Davis
NA
ES

Emily Santos

University of California, Davis
NA
KA

Kari Arnold

UC ANR
NA
PG

Paula Guzman-Delgado

University of California Davis
Friday September 27, 2024 3:45pm - 4:00pm HST
South Pacific 3
 


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