ASHS 2024 Conference: Full Schedule

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11:00am HST

TROP - Comparing The Effect Of Potyviruses On The Yield Of Different Generations Of Beauregard Sweetpotato Variety

Friday September 27, 2024 11:00am - 11:10am HST

Sweetpotatoes (Ipomoea batatas) have become increasingly popular over the last two decades. It is higher in beta-carotene than many other vegetables and a source of potassium, fiber, and vitamins A and C. Orange-fleshed varieties have a significant role in addressing vitamin A deficiencies, especially in pregnant women and children in developing countries. Sweetpotatoes are vegetatively propagated and susceptible to viruses that accumulate with each planting cycle (generation), leading to cultivar decline. This can affect the yield and quality of the sweetpotato roots. Over 30 viruses have been identified in sweetpotato. In U.S. commercial production fields, four potyviruses such as Sweetpotato feathery mottle virus (SPFMV), Sweetpotato virus G (SPVG), Sweetpotato virus 2 (SPV2), and Sweetpotato virus C (SPVC) are often commonly found. Potyviruses are aphid transmitted in a non-persistent manner. The potyvirus, Sweetpotato feathery mottle virus (SPFMV), is, by far, the most common sweetpotato virus. The objectives of the study are to compare the level of virus infection in five different generations (G1, G2, G3, G4, G6) with the yield performance in the Beauregard variety under field conditions. The different generation roots were collected from the previous experiments, and slips were multiplied under greenhouse conditions of the University of Arkansas at Pine Bluff (UAPB) farm. The slips were planted 12 inches apart with a 30-inch row spacing in four replications using a randomized block design during the summer of 2023. The roots were collected and cured to measure the various yield parameters like total marketable yield, U.S. No. 1, Jumbos Canners, and Culls. The random roots were selected to quantify the viral infections across the five generations using multiplex Reverse Transcription-Polymerase Chain Reaction (mRT-PCR). We observed significant differences in the U.S. No. 1 roots and Canners across the generations. In total marketable yield, 42.5% reduction was observed between the younger generation (G1, G2) and the older (G6) generation. Here, SPFMV was found to be dominant across the generations. Overall, a higher rate of virus infections was detected in the older generation (G6) than in younger generations (G1, G2).

Speakers

Sathish Ponniah

Friday September 27, 2024 11:00am - 11:10am HST
Lehua Suite

Poster presentation (individual talk), Tropical Horticultural Crops

SUBJECT Tropical Horticultural Crops

11:10am HST

TROP - “Midnite” and “Festival”: Combining Caribbean and African Hibiscus sabdariffa

Friday September 27, 2024 11:10am - 11:20am HST

Lehua Suite

Hibiscus sabdariffa, regionally referred to as sorrel, is a popular annual fruiting crop in the Caribbean. During the winter holiday season, sorrel calyxes are used for making flavorful and refreshing deep crimson red juices and teas. Through years of breeding and selection among Caribbean and African lines, from Ghana and Nigeria, the University of the Virgin Islands developed and released two new cultivar “Midnite” and “Festival”. “Midnite” has 20% greater production over standard Caribbean cultivars. The dark crimson-black calyxes, of both new cultivars, are full of anthocyanins and bioflavonoids. “Festival” begins bearing a month earlier than photoperiodic cultivars and production can extend to early May. Being day-neutral, “Midnite” can be grown year-round but has heavier production during late summer to late Spring. “Midnite” is being widely used in the U.S. Virgin Islands and has potential to expand its use in other commercial industries.

Speakers

Thomas Zimmerman

Assoc. Director AES, University of the Virgin Islands School of Agriculture

Friday September 27, 2024 11:10am - 11:20am HST
Lehua Suite

Poster presentation (individual talk), Tropical Horticultural Crops

SUBJECT Tropical Horticultural Crops

11:20am HST

TROP - Metabolomic Survey of Puffy Skin Date Fruit

Friday September 27, 2024 11:20am - 11:30am HST

Lehua Suite

Date palm, Phoenix dactylifera L., is one of the oldest fruit crops grown in the arid regions of the Arabian Peninsula, North Africa and the Middle East and plays a significant role in the economy, society, and environment in these areas. ‘Medjool’ is considered one of the most desirable date varieties worldwide. Skin separation, also known as “puffy skin”, is a widespread phenotypic phenomenon mostly seen in soft varieties such as‘Medjool’ and ‘Barhee’. Skin separation is a market defect that is a commercial disadvantage. In this study, we conducted a metabolomic study of 'Medjool’ fruits at the date genebank maintained in Thermal, California by the United States Department of Agriculture Agricultural Research Service. Date fruit were harvested at the tamar stage (the fruit development stage in which the puffy skin phenotype develops). The metabolomes found in mature date fruits exhibiting non-puffy and puffy phenotypes were characterized. In this study, targeted central carbon metabolism analysis was carried out to identify 126 total metabolites with 95 significant metabolites (p-value < 0.05) (75.4%). Principal Component Analysis (PCA) was carried out, revealing that specific metabolites were associated with the non-puffy skin phenotype, and other metabolites with the puffy skin phenotype.. These metabolomes included those associated with skin elasticity and integrity, supporting studies suggesting the involvement of mechanical properties of date fruit skin.

Speakers

Yoko Hiraoka

University of California Riverside/USDA-ARS

Co-authors

Esteban Rodriguez

National Clonal Germplasm Repository for Citrus and Dates, United Stated Department of Agriculture, Agricultural Research Service, U.S.

Robert Krueger

National Clonal Germplasm Repository for Citrus and Dates, United Stated Department of Agriculture, Agricultural Research Service, U.S.

Friday September 27, 2024 11:20am - 11:30am HST
Lehua Suite

Poster presentation (individual talk), Tropical Horticultural Crops

SUBJECT Tropical Horticultural Crops

11:30am HST

TROP - Identifying the formation of aroma compounds in mango using a multi-omics approach

Friday September 27, 2024 11:30am - 11:40am HST

Lehua Suite

Mango (Mangifera indica L.) is a fruit renowned for its delectable flavor, making it a staple in tropical and subtropical regions and the second most significant fruit crop in horticulture. Despite its widespread popularity, the specific compounds responsible for its distinctive aroma remain elusive. Our study aimed to bridge this gap by employing untargeted metabolomics and proteomics approaches to investigate aroma compound biosynthesis in three mango cultivars: 'Ah Ping', 'Rosa', and 'Rosigold'. Through integrated metabolomics and proteomics analysis, we identified key pathways and enzymes involved in aroma compound biosynthesis. Fatty acid metabolism, amino acid metabolism, pentose and hexose metabolism, and terpenoid metabolism emerged as pivotal pathways influencing mango flavor diversity. In 'Ah Ping', upregulation of lipoxygenase, hydroperoxide lyase, and alcohol dehydrogenase led to the accumulation of C6 and C9 volatile compounds, contributing to its distinct aroma profile. Conversely, 'Rosa' exhibited varied contents of straight-chain volatile compounds facilitated by the upregulation of enzymes involved in fatty acid degradation. Amino acid metabolism played a crucial role, with glutamate, valine, and phenylalanine serving as precursors for the biosynthesis of butyl esters and aromatic compounds in all three cultivars. Differential expression of enzymes such as aminotransferase and decarboxylase further modulated aroma compound production. Additionally, variations in furan and pyran volatile compounds were linked to differentially expressed enzymes in pentose and hexose metabolism. Our findings provide a comprehensive metabolic and proteomic map elucidating the biosynthesis of specific aroma compounds across mango cultivars. By unraveling the molecular mechanisms underlying mango flavor, this study offers valuable insights for breeding programs aimed at enhancing mango varieties with superior flavor quality. Overall, our research sheds light on the interplay between metabolism and aroma compound biosynthesis in mango, paving the way for targeted breeding strategies and improved mango flavor profiles.

Speakers

Yu Wang

University of Florida

Co-authors

Jonathan H Crane

University of Florida, TREC

Xin Liu

University of Florida

Xingbo Wu

Chair 2023-2024, University of Florida

Friday September 27, 2024 11:30am - 11:40am HST
Lehua Suite

Poster presentation (individual talk), Tropical Horticultural Crops

SUBJECT Tropical Horticultural Crops

11:30am HST

VGBR - The Power of Breeding and Genetics in Controlled Environment Horticulture

Friday September 27, 2024 11:30am - 11:40am HST

Coral 1

Controlled environment (CE) horticulture production has shown its potential to cope with the impact of climate change such as rising temperatures and declining water availability. Drives like “locally grown”, and “food miles reduction” favor CE-based food production which represents a $50 billion market for fresh, local, and sustainable food. CE production systems use advanced technology for climate control and mechanized growing practices for which infrastructure and software development have taken a good start. Contrastingly, the breeding and development of plants designed to best perform in CEs to reduce energy usage, allow automation, and increase profits are just beginning. The US CE producers can benefit from the breeding and development of new cultivars with modified stature that offer high-density planting and shortened crop cycles, ease in maintaining and harvesting, and allow automation. Utilization of plant genetics to breed for plant statures will increase crop diversity in CEs. Additionally, discovering new genetics in plant germplasms to enhance crop quality for nutrition, flavor, taste, color, and texture through breeding can meet consumer needs for fresh, high-quality, nutritious, and sustainably produced food. Several other opportunities exist where leveraging genetics to breed new crops that produce nutraceuticals, biofuel, macro and micronutrients, and bioactive compounds can sustain the CE horticulture industry, feed the increasing population, improve health, and cope with climate change.

Speakers

Krishna Bhattarai

Texas A

Friday September 27, 2024 11:30am - 11:40am HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding

SUBJECT Vegetable Breeding

11:40am HST

TROP - Establishment of Avocado trees in the United States Virgin Islands

Friday September 27, 2024 11:40am - 11:50am HST

Lehua Suite

Avocado (Persea americana Mill.), also known as pear in the Caribbean, is a staple fruit in the United States Virgin Islands (USVI) and has one of the fastest expanding markets in Europe and North America. Multiple West Indian cultivars exist. The objective of this study was to evaluate the establishment of 13 avocado varieties in the USVI. Thirteen cultivars were sourced from Florida, these cultivars are ‘Brogdon’, ‘Catalina’, ‘Choquette’, ‘Day’, ‘Donnie’, ‘Lula’, ‘Marcus Pumpkin’, ‘Monroe’, ‘Oro Negro’, ‘Pollock’, ‘Russell’, ‘Thompson Red’, and ‘Uh La La’. These grafted cultivars were planted on July 7, 2022, at 5.5 m spacing with drip irrigation installed as a 1 m diameter around the trees. Data on vertical stem growth after planting and the number of lateral shoots was collected monthly. Walk-throughs are conducted biweekly to identify when each cultivar begins flowering. Similarities in vertical stem growth and flowering were observed after 2 years. ‘Day’, ‘Marcus Pumpkin’, ‘Monroe’, ‘Oro Negro’, ‘Russell’, and ‘Thompson Red’ all grew an average of 98 cm. ‘Brogdon’ grew 137 cm which was the most vertical growth of all the cultivars and ‘Catalina’ grew only 43 cm which was the least. By the second year ‘Brogdon’, ‘Catalina’, ‘Oro Negro’, ‘Pollock’, ‘Russell’, and ‘Thompson Red’ all began flowering from January through April with ‘Pollock’ flowering the earliest in January. Avocado cultivars ‘Day’, ‘Russell’, ‘Oro Negro’, ‘Thompson Red’, and ‘Marcus Pumpkin’ have shown similarities in vertical growth over 20 months with only ‘Oro Negro’, ‘Russell’, and ‘Thompson Red’, flowering during the same months.

Speakers

Samuel Joseph

University of the Virgin Islands

Co-authors

Thomas Zimmerman

University of the Virgin Islands School of Agriculture

Friday September 27, 2024 11:40am - 11:50am HST
Lehua Suite

Poster presentation (individual talk), Tropical Horticultural Crops

SUBJECT Tropical Horticultural Crops

11:40am HST

VGBR - Novel Summer Squash: Breeding Tromboncino Types for U.S. Markets

Friday September 27, 2024 11:40am - 11:50am HST

Coral 1

Cucurbitaceae family squash and pumpkins are all New World domesticates from different parts of the Americas. While many types are eaten as winter squash at full maturity, others – termed summer squash – are used as vegetable where the immature fruit is eaten. The summer squash we are most familiar with belong to the species Cucurbita pepo. The immature fruit of C. maxima and C. moschata are sometimes used as summer squash and a few land race types have been developed mainly for summer squash use. ‘Tromboncino’ (also called Trombetta or Zucchetta Rampicante), is one such C. moschata summer squash from the Ligura region of Italy. It is most closely related to the butternut winter squashes. Originally domesticated in the tropical lowlands of Middle America, it is more tolerant of high temperatures, humidity and pest and diseases. Tromboncino is essentially a butternut squash with an extended neck that has been adapted to use as an immature vegetable but can also be used as a winter squash. The heritage varieties of Tromboncino are long-vined with prolific fruit production and produce few seeds. The seeds are found in a bulb at the end of the fruit, leaving a long seedless neck for culinary preparation. It has a firmer, meatier texture and a flavor profile that is more similar to a mature butternut squash. Tromboncinos are at their highest quality when used at 6-12" long, but they can be eaten at later stages until fully mature. The main breeding objective of the OSU vegetable breeding program was to develop a tromboncino type with better adaptation to the cool summers of Western Oregon, shift plant architecture to a bush plant habit while retaining prolificacy, and shorten fruit length for fresh market production. Another objective was to combine the tromboncino type with skin colors other than the traditional tan color of the heritage variety. We have been able to accomplish most objectives although the plant architecture is not yet comparable to the bush habit of C. pepo summer squash. Some types have dark green as well as yellow skin colors (conditioned by the precocious yellow gene). Two advanced lines are in the process of being released.

Speakers

James Myers

Oregon State University

Co-authors

Emma Landgraver

Oregon State University

Joel Davis

Oregon State University

Friday September 27, 2024 11:40am - 11:50am HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding

SUBJECT Vegetable Breeding

11:45am HST

PB - PoDRM2: Unveiling a Key Regulator of Biomass Production and Starch Accumulation in Arabidopsis thaliana

Friday September 27, 2024 11:45am - 11:55am HST

South Pacific 3

Starch, a vital dietary component and crucial for bio-ethanol generation, is synthesized by plants during photosynthesis. Augmenting starch output holds promise for human and animal nutrition, as well as bioenergy. Our previous work involved cloning the homolog gene DRM2 from Purslane and subsequently overexpressing PoDRM2 in Arabidopsis. Comparative analysis between wild-type Columbia and homozygous PoDRM2 transgenic lines revealed a substantial increase in plant size and nearly a 90% rise in fresh biomass per plant in PoDRM2 lines, indicating a potentially heightened efficiency in photosynthesis. We conducted further investigations into starch synthesis and accumulation in leaves. Iodine staining revealed that PoDRM2 transgenic Arabidopsis lines accumulated significantly more starch than the control under both dark and light conditions. Additionally, total carbohydrates in the leaves of transgenic lines more than doubled that of the wild type. Furthermore, PoDRM2 lines exhibited higher chlorophyll content compared to the control. These findings strongly indicate that PoDRM2 serves as a crucial regulator of starch accumulation. PoDRM2, encoding a methyltransferase, was implicated in altering the methylation status of over 2,500 genes through genome-wide bisulfite sequencing. Notably, 55 out of 61 genes involved in the photosynthesis pathway were affected, underscoring the significant role of DNA methylation in regulating starch accumulation and photosynthesis in plants.

Speakers

Jian Huang

Virgina State University

Friday September 27, 2024 11:45am - 11:55am HST
South Pacific 3

Poster presentation (individual talk), Plant Biotechnology

SUBJECT Plant Biotechnology

11:50am HST

VGBR - Mapping QTL for Bacterial wilt resistance and plant height in Tomatoes

Friday September 27, 2024 11:50am - 12:00pm HST

Coral 1

Bacterial wilt (BW) of tomatoes, caused by Ralstonia solanacearum, is a devastating dis-ease that results in large annual yield losses worldwide. Management of BW of toma-toes is difficult due to the soil-borne nature of the pathogen. One of the best ways to mitigate the losses is through breeding for disease resistance. Moreover, plant height (PH) is a crucial element related to plant architecture which determines nutrient management and mechanical harvesting in tomatoes. An intra-specific F2 segregating population (NC 11212) of tomatoes was developed by crossing NC 84173 (tall, BW susceptible) x CLN1466EA (short, BW resistant). We performed quantitative trait loci (QTL) mapping using single nucleotide polymorphic (SNP) markers and the NC 11212 F2 segregating population. The QTL analysis for BW resistance revealed a total of three QTLs on chromosomes 1, 2, and 3, explaining phenotypic variation (R2) ranging from 3.6% to 14.9%. Whereas, QTL analysis for PH also detected three QTLs on chromo-somes 1, 8, and 11 explaining R2 ranging from 7.1% to 11%. This work thus provides information to improve BW resistance and plant architecture-related traits in toma-toes.

Speakers

Frank Louws

NCSU

Co-authors

Dilip Panthee

North Carolina State University

Emily Silverman

North Carolina State University

Muhammad Irfan Siddique

North Carolina State University

Friday September 27, 2024 11:50am - 12:00pm HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding

SUBJECT Vegetable Breeding

11:55am HST

PB - Efficient high molecular weight DNA isolation and whole genome sequencing of papaya for molecular applications

Friday September 27, 2024 11:55am - 12:05pm HST

South Pacific 3

Plant whole genome sequencing provides detailed information on gene content, genome organization, and evolutionary relationships as well as supports biotechnological applications such as gene editing. The first 3X draft genome sequence of papaya based on whole genome shotgun reads from the transgenic ‘SunUp’ papaya cultivar was published in 2008. Since then, advancements in sequencing and whole genome assembly enabled a near complete sequence of ‘SunUp’ and a detailed picture of events resulting from particle gun-mediated transformation. With current technology, the 372 Mb genome size of papaya makes it tractable for routine whole genome sequencing to characterize different cultivars and molecular events. In this study, we improved ease and speed of preparation, efficiency of recovery, and DNA quality through a combination of classical and contemporary plant nuclei or high molecular weight DNA isolation methods. Leveraging Hi-Fi sequencing and Hi-C technology, we achieved rapid chromosome-level sequence assembly of two local Hawaiian cultivars, Kapoho and Waimanalo. The assembled genomes of Kapoho and Waimanalo spanned 341.6 Mb and 337.4 Mb, respectively, with a total of 20,343 and 20,165 annotated protein-coding genes.

Speakers

Jon Suzuki

USDA ARS DKI U.S. PBARC

Co-authors

Angela Kauwe

USDA

Briette Corpuz

USDA ARS US DKI PBARC

Haomin Lyu

USDA ARS Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center

Qingyi Yu

USDA, ARS, Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center

Renee Corpuz

USDA-ARS

Scott Geib

USDA-ARS

Sheina Sim

USDA-ARS

Friday September 27, 2024 11:55am - 12:05pm HST
South Pacific 3

Poster presentation (individual talk), Plant Biotechnology

SUBJECT Plant Biotechnology

12:00pm HST

VGBR - Effects of Prolonged Photoperiod on Chile Pepper Plant Architecture and Growth Habit

Friday September 27, 2024 12:00pm - 12:10pm HST

Coral 1

This experiment sought to examine the effects of prolonged photoperiod and modified temperature and humidity in chile peppers, aiming to develop a protocol to accelerate their growth and enhance breeding efficiency. Four genotypes from three Capsicum species (C. annuum - Chimayo, Early Jalapeno; C. chinense - Orange Habanero; Chiltepin - C. annuum var. glabriusculum) were planted in two randomized flat trays per entry using SunGro propagation soil. After reaching the 2-3 leaf stage, they were transplanted into 8” pots, incorporating sterilized and LM-AP soil mixtures. The experimental population was grown in an improvised growth chamber with an average temperature of 25°C and humidity of 60% and exposed to a 20-hour daily cycle of 450 nm full spectrum LED grow lights and 730 nm Far Red LED grow lights and 4 hours of darkness. The control group grew in normal greenhouse conditions, exposed to normal daylight intensity and duration and an average temperature of 21°C and humidity of 40%. Weekly data recordings included plant growth measurements of plant height and leaf count. Basal branches were counted approximately 12 weeks after planting, and leaf widths were recorded 14 weeks after transplanting. Number of flowers and fruits were also recorded at 14 weeks after transplanting. Data were analyzed using RStudio, and Tukey HSD was used to detect differences between treatments and among genotypes. In terms of plant height, all experimental plants demonstrated a significant increase compared to the control group, both in absolute amounts and in rates, especially later in the growth stage. The leaf numbers in experimental plants were significantly lower than the control group, except for Orange Habanero, which showed no significant difference. Early Jalapeno, in both treatments, exhibited no significant difference in basal branches. In contrast, the remaining experimental plants displayed fewer or no basal branches compared to the control group. All experimental plants exhibited significantly wider leaves in comparison with the control group. While most experimental plants started flowering earlier, no significant differences were observed between numbers of flowers and fruits. The faster growth rates observed hold the promise of accelerated progress and improved efficiency in breeding initiatives, offering a fundamental shift in the way we approach crop development. Additionally, fewer number of basal branches may have implications for machine harvestability, as fewer basal branches is considered a desirable trait for machine harvesting.

Speakers

Shahab Nourbakhsh

New Mexico State University

Co-authors

Dennis Nicuh Lozada

New Mexico State University

Isaac Porras

New Mexico State University

Lily Northcutt

Second Author, New Mexico State University

Rhiannon Rodriguez

New Mexico State University

Tyra Trumble

New Mexico State University

Friday September 27, 2024 12:00pm - 12:10pm HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding

SUBJECT Vegetable Breeding

12:00pm HST

WUM - Evaluating Saline Irrigation Management Strategies Under Drip Irrigated Pistachio

Friday September 27, 2024 12:00pm - 12:10pm HST

Nautilus

Over 85% of California's bearing pistachio acreage is located in soils with moderate (4 dS/m) to extremely high (16 dS/m) saline. Several previous studies have demonstrated that pistachios can be grown profitably even in moderately saline soils, with optimal soil salinity (ECe) maintained at approximately 4.5 - 6 dS/m. One common practice to reduce the salinity level in rootzone is to apply good quality water during dormant season. As the availability of good quality canal water for in-season irrigation and dormant season leaching declines, growers are relying more on semi-saline pumped groundwater, particularly in the San Joaquin Valley Westside. It would be beneficial to understand if the volume of dormant season leaching could be reduced, if in-season methods of leaching could be effective, and how to use moderately saline water most efficiently for both dormant and in-season leaching. Current methods for managing salinity through dormant leaching rely on one-dimensional models assuming complete surface wetting. We are exploring alternative approaches, investigating the effectiveness of single and double drip lines in managing root zone salinity using in-row, in-season leaching fractions and small volume pulsed dormant leaching. Preliminary results showed that generally, all leaching treatments, (in-season leaching, dormant leaching and the combination of both, applied with both single and double hose lines, significantly decreased soil ECe relative to the control, reducing ECe values of 13-22% relative to their respective controls. All the leaching treatments also effectively prevented boron from accumulating in the soil relative to the control. No clear effects of line configuration, double versus single line, were detected in soil levels. These findings indicate that treatments are effectively reducing salinity or at least preventing the increases observed in the control. Leaf analysis showed that in-season leaching, with/without dormant leaching, significantly increased leaf nitrogen and phosphorus, and reduced leaf boron accumulation.

Speakers

Mukesh Mehata

University of California, Davis

Co-authors

Blake Mccullough Sanden

University of California Davis

Clay Beck

Maricopa Orchard

Donald Williams III

CSU Fresno

Giulia Marino

University of California, Davis

Joseph Coehlo

Valley Orchard LLC

Louise Ferguson

University of California, Davis

Mae Culumber

University of California, Davis

Marta Saludes

Universidad de Salamanca

Friday September 27, 2024 12:00pm - 12:10pm HST
Nautilus

Poster presentation (individual talk), Water Utilization and Management

SUBJECT Water Utilization and Management

12:05pm HST

PB - Tissue Culture Regeneration of Miscanthus Sinensis ’Gracillimus’

Friday September 27, 2024 12:05pm - 12:15pm HST

South Pacific 3

The genus Miscanthus is considered an ideal choice for both ornamental and biofuel purposes, owing to its appealing aesthetics and significant potential for high-energy biomass production. Traditional breeding efforts in Miscanthus have predominantly focused on enhancing nutrient efficiency and tolerance to both biotic and abiotic stresses. However, these endeavors are often time-consuming. The emergence of plant genome editing technologies has opened up a new and efficient avenue for Miscanthus breeding. These innovative techniques hold promise for accelerating the breeding process, allowing for more rapid and targeted improvements in desired traits. The development of an efficient plant regeneration system is crucial for the application of modern genome editing technologies in Miscanthus breeding and for achieving large-scale biomass production. Among the Miscanthus species, Miscanthus sinensis poses a particular challenge in tissue culture regeneration. In this report, we present an effective system for callus induction and regeneration in Miscanthus sinensis. Callus was induced from the stems of in vitro-cultured Miscanthus sinensis 'Gracillimus' using a modified MS media supplemented with varying levels of 2,4-D. Regeneration-competent callus was achieved through continuous selection on the callus maintenance/selection medium over a period of 6 months. Remarkably, 100% of the callus successfully regenerated new shoots on a modified MS medium containing Benzylaminopurine (6-BA) and α-Naphthaleneacetic acid (NAA). This marks the first efficient 'Gracillimus' regeneration system using in vitro culture as the starting material. The established system demonstrates a high potential for the micropropagation of Miscanthus sinensis 'Gracillimus' with a propagation rate of 3.5. Currently, efforts are underway for genome editing of Miscanthus sinensis utilizing this established system.

Speakers

Kedong Da

North Carolina State University

Director of plant transformation lab at North Carolina State University

Co-authors

Anna Nelson

NC State University

Huani Leng

North Carolina State University

John Nix

NC State University

Keren Morales

North Carolina State University

Sydney McLennan

North Carolina State University

Thomas Ranny

North Carolina State University

Wusheng Liu

North Carolina State University

Friday September 27, 2024 12:05pm - 12:15pm HST
South Pacific 3

Poster presentation (individual talk), Plant Biotechnology

SUBJECT Plant Biotechnology

12:10pm HST

VGBR - Seasonal Lettuce Germplasm Trials in Northeast Florida Hydroponics

Friday September 27, 2024 12:10pm - 12:20pm HST

Coral 1

The Hastings Agricultural Extension Center adopted the lettuce variety trials in 2018 for the demonstration of alternative row crops. Within the Tri-County Agricultural Area (TCAA), the term "alternative" refers to any crops outside of the traditional rotations - potatoes and cabbage. While these crops are the staple of the community, the acreage has been reduced due to tight profit margins and competitiveness for chipping contracts. Lettuce, along with artichokes and pumpkins, have been one of the newly adopted commodities for North Florida. What initially began as field trials expanded into the controlled systems of protected agricultural and hydroponics. Three seasons of germplasm trials with 14 newly developed lines in the hydroponic towers were conducted in Hastings to evaluate their soilless potential. Under 20% shade, lettuce was grown in the Verti-Gro system with 40% perlite, 30% coconut coir and 30% peat moss. These trials were also home to many field tours for the community, and opportunities for local growers to witness and observe their growth habits. Data evaluations included marketability, timing (if observed) of bolting, tip burn, and head weights. Weights ranged from 0.10 - 0.85 kg, with Botrytis and Sclerotinia being the most common disease pest identified. Since the trials began, our lettuce acreage has increased from 15 to 100 in the county, including two organic growers and one conventional, and with opportunities for more research to benefit these diversified growers.

Speakers

Evelyn "Prissy" Fletcher

Faculty - UF/IFAS Lecturer, University of Florida

I am a lecturer and academic advisor for the Soil, Water and Ecosystem Sciences Department. My research and extension background included alternative crop assessments for Florida growers, insecticide fate and transport in citrus and phosphorus nutrient management in artichokes. These... Read More →

German Sandoya

University of Florida

Friday September 27, 2024 12:10pm - 12:20pm HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding

SUBJECT Vegetable Breeding

12:10pm HST

WUM - Lysimetric Determination of Crop Water Requirements for Sorghum

Friday September 27, 2024 12:10pm - 12:20pm HST

Nautilus

Accurate estimation of crop water requirements (CWR) is essential to optimize water use efficiency and develop efficient irrigation scheduling practices. This is particularly important in California where frequent droughts have accentuated the need to conserve water and improve on-farm water management. The most accurate method to determine CWR is with precision weighing lysimeters, which measure actual crop evapotranspiration (ETa). Thus, the objectives of this study were to determine ETa data, develop new crop coefficients (Kc), and evaluate the relationship between Kc and crop fractional ground cover (Fc) for forage sorghum grown under drip irrigation. Being drought and salt tolerant, sorghum has been considered as an alternative crop to corn in regions of water scarcity and marginal soils. Daily ETa measurements were collected over three years on a clay loam soil using the precision weighing lysimeter available at the University of California Westside Research and Extension Center in Five Points, CA. Crop coefficient (Kc) estimates were derived from the ETa measurements and reference ETo data were obtained from a CIMIS weather station located at the study site. Weekly Fc measurements were also performed to derive relationships between Kc and fractional ground cover. Results from our study indicated that the seasonal ETc ranged from 665 to 870 mm, with average peak ET of 7.0 mm/day and midseason Kc spanning from 0.90 to 1.1. A strong correlation (r2 > 0.95) was also observed between crop Kc and Fc. This study represents the first experiment determining ETc and Kc for forage sorghum grown under drip irrigation in California. Findings also demonstrated the variability of CWR due to seasonal differences.

Speakers

Florence Cassel

California State University, Fresno

Co-authors

Dave Goorahoo

California State University, Fresno

Idalia Navarro

California State University, Fresno

Rafael Solorio

California State University, Fresno

Shawn Ashkan

California State University, Fresno

Friday September 27, 2024 12:10pm - 12:20pm HST
Nautilus

Poster presentation (individual talk), Water Utilization and Management

SUBJECT Water Utilization and Management

12:15pm HST

CITR - Encouraging Homeowner Citrus in Florida

Friday September 27, 2024 12:15pm - 12:25pm HST

Kahili

Background: Florida’s Citrus industry has been devastated by the bacterial disease, Huanglongbing (HLB) (Candidatus Liberibacter asiaticus). The vector of the disease is the Asian Citrus Psyllid (Diaphorina citri). HLB is not just a problem in Florida but affects other citrus-growing areas across the United States. Many homeowner citrus trees already have HLB or have succumbed to the disease. Often, young trees are purchased and decline before they have harvestable fruit. Many homeowners, not educated on the disease, have become disenchanted with attempting to grow citrus. Although no citrus is resistant to HLB, there are tolerant varieties. Objective: Engage Highlands County residents to grow citrus in their yards by offering classes on the proper use of cultural practices to successfully maintain a tree that would supply quality fruit for a longer duration. Introduce them to HLB-tolerant trees and other innovations. Method: Lecture using a two-hour PowerPoint on growing citrus. Teach participants how to identify HLB and other common citrus pests and diseases. Give them a better understanding of citrus nutrition, soil health, and irrigation practices. Introduce them to Individual Protective Covers (IPCs) that can exclude Asian Citrus Psyllids from reaching their trees. Send them home with the knowledge to grow successful citrus at home. Conclusion: In 2023 and 2024, 112 participants attended the Growing Citrus at Home program. Of this, 92 trees were taken home each with an IPC. Seventy-five class participants took a pre- and post-assessment to ascertain knowledge gain. Knowledge gain based on a 10-question pre-and post-assessment went from 36% to 68% which calculates to be an increase of 89 %. pests and diseases. Give them a better understanding of citrus nutrition, soil health, and irrigation practices. Introduce them to Individual Protective Covers (IPCs) that can exclude Asian Citrus Psyllids from reaching their trees. Send them home with the knowledge to grow successful citrus at home. Conclusion: In 2023 and 2024 112 participants attended the Growing Citrus at Home program.

Speakers

David Austin

Urban Horticulture Agent 1, UF/IFAS

David Austin is a Residential Horticulture Agent for UF/IFAS Extension, Highlands County, and their Master Gardener Volunteer Coordinator. He has a Bachelor of Science in Horticulture from the University of Florida in 1984 and is presently working on his Masters in Landscape Pest... Read More →

Friday September 27, 2024 12:15pm - 12:25pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

12:15pm HST

O/LT 2 - Impact of Lawn Age on Soil Organic Matter, Microbial Respiration, and Nitrogen Mineralization

Friday September 27, 2024 12:15pm - 12:25pm HST

Coral 2

Aesthetically appealing and ecosystem servicing turfgrass lawns require proper nutrition and adequate water, which are generally provided by fertilization and supplemental irrigation. However, mismanaged fertilizer and irrigation practices can lead to nutrient losses to the environment, especially nitrogen (N). Model simulations suggest that as the age of the turf stand increases it may be possible to reduce N fertilization and still maintain acceptable turf quality. This is likely due to increases in soil organic matter with turf maturation, which has the potential to provide plant-available N. However, little research has been performed on carbon (C) sequestration and N mineralization in urban residential soils in Florida. It is hypothesized that as lawn age increases it will result in greater C sequestration, microbial activity, and N mineralization. This study was conducted at Lakewood Ranch, FL. Soil samples were collected from lawns with the following ages: 1, 3, 5, 10, 15, and 20 years old. The soil samples were sieved, homogenized, and air-dried prior to soil analysis. Soil analysis included soil organic matter (loss-on-ignition), microbial activity (potentially mineralizable C), and N mineralization (potentially mineralizable N). Data was subjected to analysis of variance (ANOVA) and treatment mean comparisons were separated using Fisher's least significant difference (LSD) at the p ≤ 0.05 level. Lawn age had an impact on soil organic matter, microbial activity, and N mineralization. In general, as a lawn ages, especially after 5 years, it increases the soil organic matter, microbial respiration, and N mineralization. This is the first-year data and a second year with multiple locations will be evaluated to confirm results. Future studies will involve optimizing fertilizer and irrigation recommendations for lawns of various ages.

Speakers

AJ Lindsey

University of Florida

Friday September 27, 2024 12:15pm - 12:25pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

12:15pm HST

PB - In Vitro Shoot Regeneration Protocol For Southern Highbush Blueberry (SHB) Cultivars.

Friday September 27, 2024 12:15pm - 12:25pm HST

South Pacific 3

Blueberry (Vaccinium sp. L.) is one of the most important fruit crops from the Ericaceae family and the highbush blueberry (Vaccinium corymbosum) is the most widely grown species. It's popularity is increasing day-by-day because of their unique flavor and rich nutritional content. Consequently, significant efforts have been made to develop superior cultivars with high yield, biotic and abiotic stress resistance using conventional breeding. However, due to high heterozygosity, polyploidy and long juvenile period, traditional breeding approaches can often be tedious and time consuming. Therefore, there is need to integrate modern precision breeding tools with traditional ones, to accelerate blueberry crop improvement. However, the success of novel biotechnological tools like gene editing and conventional transformation relies on successful shoot regeneration system. Many studies in blueberry show a lack of reliable regeneration protocols and their genotype-dependency. Furthermore, most of the reported regeneration studies have been conducted on northern highbush blueberry (NHB) cultivars. Therefore, the current study aims to develop shoot regeneration protocol for seven important southern highbush blueberry (SHB) cultivars (Colossus, Optimus, Albus, Arcadia, Keecrsip, FL 14-242

Speakers

Anandi Karn

University of Florida

Friday September 27, 2024 12:15pm - 12:25pm HST
South Pacific 3

Poster presentation (individual talk), Plant Biotechnology

SUBJECT Plant Biotechnology

12:15pm HST

PH 3 - Evaluating the Potential of Gaseous Ozone to Suppress Decay Incidence in Fresh Peaches During Cold Storage

Friday September 27, 2024 12:15pm - 12:25pm HST

Lehua Suite

Sanitizing fruit and vegetables with gaseous ozone promotes food safety, marketability, and extended postharvest shelf-life. Ozone is a self-decomposing gas that disinfects and neutralizes microorganisms on packing equipment, water, and produce surfaces. The USDA permits ozone use in "organic" products. Ozone is produced on-site through a corona discharge mechanism using commercially gaseous ozone generators. This study studied gaseous ozone application on peaches, ranging from 0.5 - 5 ppm compared to control storage (CS). Gaseous ozone applications are known for postharvest spoilage vulnerability to assess microbial load reduction and defense against diseases like brown rot and gray mold. Investigated varieties (July Prince, Scarlet Prince, August Lady, and O’Henry), stored under controlled conditions of 35°F (1.7°C) at 90% relative humidity, revealed that 5 ppm ozone resulted in high decay (~40-42%). However, 0.5 ppm treatment maintained peach quality comparable to controls, with decay rates between 3.5 to 7%. Notably, peaches treated with 0.5 ppm also exhibited higher firmness than the other treatments and unaffected visual quality up to the 28th storage day. The findings suggest ozone’s potential to enhance postharvest practices, highlighting its efficiency, and could serve as an effective counteract treatment for decay incidence that will benefit the peach industry.

Speakers

Orestis Giannopoulos

Graduate Research Assistant, University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Camille Esmel McAvoy

University of Georgia

Dario Chavez

University of Georgia

Ramsey Corn

University of Georgia

Friday September 27, 2024 12:15pm - 12:25pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

12:20pm HST

VGBR - Marker Development for Cadmium Accumulation in Spinach

Friday September 27, 2024 12:20pm - 12:30pm HST

Coral 1

California is the largest spinach producing state in the USA, accounting for 75% of hectares planted. The major production area is the Salinas Valley, which is known to have geogenic cadmium soils. Spinach is a hyperaccumulator and its affinity for divalent cations, like zinc and iron, likely contributes to the accumulation of Cd. Cadmium has known adverse health effects in humans, so California’s Office of Environmental Health Hazard Assessment’s (OEHHA) set a limit of 4.1 ug Cd per day by consumption. Consequently, growers do not produce spinach on high cadmium soils, limiting their ability to rotate crops throughout the valley. Even so, a few fresh leaf market spinach samples with foliar concentrations of Cd above the limit have been reported.

Our long-range objective is to develop improved fresh market spinach germplasm that restricts Cd uptake while maintaining nutritional quality. We have observed phenotypic variation for foliar cadmium concentration in a wide diversity of spinach germplasm with over 500 accessions originating from 42 countries, showed that greenhouse evaluations in high Cd soil largely reflected phenotypic performance in the field, and developed populations segregating for Cd uptake. We have also developed a hydroponic system that reflects field and greenhouse Cd uptake, but that is more controlled and scalable. Our current objectives are to identify quantitative trait loci (QTL) in the spinach genome associated with Cd accumulation. We have developed a biparental mapping population for genetic mapping by crossing high and low individuals which was evaluated in hydroponics earlier this year and will be evaluated in field conditions this fall. Markers tagging major QTL loci will be developed into high-throughput KASP markers for routine use in breeding.

Speakers

Danyelle Forte

Graduate Student, University of California - UC Davis

I study plant breeding, heavy metals and plants, plant nutrition, and spinach.

Co-authors

Allen Van Deynze

University of California Davis

Allison Krill-Brown

University of California Davis

Daniel Pap

University of California Davis

E. Charles Brummer

University of California Davis

Marcia Carvalho

University of California Davis

Richard Smith

University of California Davis

Friday September 27, 2024 12:20pm - 12:30pm HST
Coral 1

Poster presentation (individual talk), Vegetable Breeding 1

SUBJECT Vegetable Breeding

12:20pm HST

WUM - Evaluating the distribution uniformity of spray-stakes using pressure compensating emitters

Friday September 27, 2024 12:20pm - 12:30pm HST

Nautilus

Spray-stakes technology is common in nursery production systems, yet their distribution uniformity has been poorly studied. Recent innovations have the potential to increase distribution uniformity, but may be cost prohibitive. We analyzed the distribution uniformity of two brands of spray-stakes with and without pressure compensating emitters. We then conducted an economic analysis of switching from non-pressure compensating emitters to pressure compensating emitters. The average distribution uniformity measured was: 0.85 for non-pressure compensating Netafim Spray Stakes, 0.82 for the non-pressure compensating Primerus Spot Spitters, 0.95 for pressure compensating Netafim spray stakes, and 0.95 for pressure compensating Primerus Spot Spitters. While pressure compensating emitters do increase distribution uniformity, it would take 4-6 years based on water savings for the investment in pressure compensating emitters to break even, based on Southern California water prices.

Speakers

Chris Shogren

UCCE Los Angeles

Co-authors

Gerry Spinelli

University of California Cooperative Extension

Friday September 27, 2024 12:20pm - 12:30pm HST
Nautilus

Poster presentation (individual talk), Water Utilization and Management

SUBJECT Water Utilization and Management

12:25pm HST

CITR - Effect of Molybdenum Fertilization on Young Huanglongbing-Affected Citrus Trees

Friday September 27, 2024 12:25pm - 12:35pm HST

Kahili

Optimal nutrient management improves the performance of citrus trees affected by Huanglongbing (HLB) in Florida. Current research suggests that HLB-affected trees may require higher levels of micronutrients than those typically recommended for citrus production to achieve optimum nutrition. However, application rates of some micronutrients like Molybdenum (Mo) remain unknown. Therefore, a study is being conducted at UF/IFAS Citrus Research & Education Center to evaluate the effect of varying rates of Mo on citrus tree growth and biomass accumulation of 2-year-old HLB-affected and HLB-free Valencia (Citrus sinensis L. Obserk) on Swingle citrumelo rootstock under greenhouse conditions. Four varying rates of Mo (0.0 kg·ha−1 Mo (Control), 1.12 kg·ha−1 Mo (1×-standard rate), 2.24 kg·ha−1 Mo (2×-standard rate), and 4.48 kg·ha−1 Mo (4×-standard rate) are applied to both HLB and non-HLB trees in a completely randomized design. Preliminary results from the study show that different Mo rates impact tree growth. In HLB-affected trees, 4.48 kg·ha-1 (4×-standard rate) Mo treatment resulted in the lowest height, probably due to toxicity, while 2.24 kg·ha-1 (2×-standard rate) treatment had the lowest height among unaffected trees. No significant differences in trunk diameter were observed among HLB-affected trees, whereas those subjected to 4.48 kg·ha-1 (4×-standard rate) showed the smallest trunk diameter among unaffected trees. The results also showed no statistical differences between above-ground and below-ground biomass accumulation and leaf Mo uptake. Our findings suggest that applying 4.48 kg·ha-1 (4× UF/IFAS current standard rate) may adversely impact key plant growth parameters.

Speakers

Kondwani Kamsikiri

University of Florida

Co-authors

Davie Kadyampakeni

University of Florida

Friday September 27, 2024 12:25pm - 12:35pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

12:25pm HST

O/LT 2 - Effect of Organic Fertilizers and Biostimulants on ‘TifEagle’ Bermudagrass Greens

Friday September 27, 2024 12:25pm - 12:35pm HST

Coral 2

Turfgrass areas and golf industry have been under scrutiny for their potential impact on the environment, but more environmentally friendly organic fertilizers are increasingly being used to reduce and replace some inorganic fertilizers. A study was conducted on an 8-year-old ‘Tifeagle’ ultradwarf bermudagrass green mowed daily at 0.125 in. located at the University of Florida’s Fort Lauderdale Research and Education Center, Davie, FL to evaluate the effect organic fertilizers and biostimulants on turfgrass performance of Tifeagle’ bermudagrass green. Treatments included: a) XP Stress Rx (applied at 6 6 fl oz./1000 sq. ft.); b) XP-N Stress Rx (applied at 6 6 fl oz./1000 sq. ft.); XP-N Stress Rx Nautilus NuRelease (applied at 6 6 6 0.35 fl oz./1000 sq. ft.). Initial treatment was applied on June 1, 2023, with subsequent applications every 14 days for a total of nine applications. Data was collected every two weeks until three weeks after final application. Turf quality was measured on a 1-9 scale with 9=dark green dense turf, 1=dead/brown turf, and 6=minimally acceptable turf; Normalized Difference Vegetation Index (NDVI) was assessed using a RapidSCAN CS-45; percent green cover and Dark Green Color Index (DGCI) were assessed through Digital Image Analysis of one image taken per plot; volumetric water content was measured at a 3-inch depth using a time domain reflectance sensor. During the summer turfgrass quality, NDVI and DGCI were affected by treatment applications during five of the rating days. Overall, turfgrass fertilized with XP Stress Rx, XP-N Stress Rx and XP-N Stress Rx Nautilus NuRelease showed a higher quality, NDVI and DGCI compared to the unfertilized. Volumetric water content was affected by treatments only after the first application, and no differences were found thereafter. When temperature dropped, and up to three months after last application, biostimulants had a tremendous effect on ultradwarf bermudagrass health preventing the grass from Curvularia spp. infection and helping turfgrass maintaining quality and functionality through the winter.

Speakers

Marco Schiavon

Assistant Professor, University of Florida

Co-authors

Alejandra Sierra

University of Florida

Friday September 27, 2024 12:25pm - 12:35pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

12:25pm HST

PH 3 - Evaluation of different reflectance models to predict fruit firmness using compression values in sweet cherries cv ‘S

Friday September 27, 2024 12:25pm - 12:35pm HST

Lehua Suite

The compression test is the standard procedure to measure fruit firmness in sweet cherries. Nevertheless, this measurement is not always well correlated with perceived texture by buyers and consumers; therefore, the cherry industry needs a better way to grade fruit firmness. Hyperspectral information was correlated to fruit firmness as an alternative to compression values. ‘Skeena’ cherries, grown under commercial conditions in central Washington, were harvested in 2023 and stored for 30 days at 0-1oC. Compression measurements (at 20oC; FirmTech 2, BioWorks Inc) were carried out at harvest and 15 and 30 days into storage. Immediately after these measurements, hyperspectral images from the fruit (n=1030) were taken using a Vi-NIR camera (Headwall Photonics). The comparison between low (< 303 mm/g), medium (303-374 mm/g), and high firmness (>374 mm/g) groups did not yield any spectral differences. Despite this, iPLS wavelength selection showed bands > 800 nm suitable to model these compression groups. On the other hand, Neural Network, Random Forest, and PLS models were not able to predict compression values (regression) or firmness groups (classification). Furthermore, the regression models tested did not have coefficients of determination higher than 0.42 with root mean squared errors of 40 mm/g for compression values with the training dataset. Classification models achieved total accuracies of around 65-70 % and had problems distinguishing between low-medium and medium-high compression values. All models showed poor performance when tested with an independent data set. These results are in contrast to previous reports, which used a lower fruit number, reinforcing the challenge of tailoring a non-destructive technique to predict firmness through compression values in sweet cherries, a highly variable phenotypic characteristic.

Speakers

Rene Mogollon

Washington State University

Co-authors

Carolina Torres

Washington State University

Friday September 27, 2024 12:25pm - 12:35pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

12:35pm HST

CITR - Investigating the Impact of Macronutrient Management on Performance of Huanglongbing (HLB)-Affected Sweet Oranges.

Friday September 27, 2024 12:35pm - 12:45pm HST

Kahili

Concerns about eutrophication that causes blooms of blue-green algae have strengthened over the last several decades due to the excessive use of pesticides and fertilizers, particularly those containing nitrogen (N) and phosphorus (P). These substances leached from agricultural fields and citrus groves into groundwater sources. Consequently, researchers developed best management practices (BMP) which are now being used to safeguard the environment while raising agricultural productivity. Additionally, Florida citrus production has decreased by more than 70% due to huanglongbing (HLB). Macro and micronutrient uptake is constrained owing to the decreased fibrous root density which may inflict root loss of up to 80%, depending on the severity of HLB-affected trees. The standard recommended rates of N and P were developed before the incidence of HLB and are no longer valid and warrant further refinement. Therefore, new site-specific guidelines are needed for the present situation. A study was started on 11-year-old ‘Valencia’ sweet orange trees (Citrus sinensis (L.) Osbeck) on Swingle citrumelo (Citrus paradisi Macf. × Poncirus trifoliata L. Raf.) rootstock in central Florida on Candler fine sand in 2023 to evaluate the impact of N and P fertilization on the growth and yield of HLB-affected citrus trees as well as to determine the optimal N and P rates for HLB-affected citrus trees in Florida. Eight treatments will be used over three years, with two N rates (112 and 224 kg/ha) as main plots and four P rates (0, 8.9, 17.8, and 35.7 kg/ha) as subplots in a factorial randomized complete block design. Tree height, canopy size, trunk diameter, fruit output, and juice quality are among the variables that will be measured. We anticipate that treatments that receive additional fertilization over the current recommendation have a significant chance of enhancing citrus growth and production. Keywords: Best management practices (BMP), Citrus sinensis, Huanglongbing, Site-specific nutrient management.

Speakers

Monika Peddapuli

UNIVERSITY OF FLORIDA

Co-authors

Alisheikh Atta

UNIVERSITY OF FLORIDA

Alisheikh Atta currently works at the Department of Soil, Water, and Ecosystem Science, University of Florida. Alisheikh does research on HLB-affected citrus nutrient and water management. He studies the impact of plant nutrients on the performance of citrus trees, irrigation water... Read More →

Davie Kadyampakeni

UNIVERSITY OF FLORIDA

Friday September 27, 2024 12:35pm - 12:45pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

12:35pm HST

O/LT 2 - Detection of QTL Associated with Morphological, Adaptive, and Reproductive Traits in Common Bermudagrass

Friday September 27, 2024 12:35pm - 12:45pm HST

Coral 2

Cynodon dactylon (L.) Pers. is frequently used as turf and to cross with C. transvaalensis Burtt-Davy in the creation of F1 hybrid cultivars that are widely used on home lawns, golf courses, and sports fields worldwide. However, molecular information associated with adaptive and morphological traits in this species is limited. Accordingly, the objectives of this study were to identify genomic regions associated with establishment rate, spring green-up, drought response, leaf length and width, and stem internode length and width. In this study, we used a ‘A12359’ common bermudagrass high-density linkage map constructed with 3,544 markers. A total of 130 first-generation selfed progeny were evaluated in the field for two seasons for adaptive and morphological traits. A total of 36 genomic regions were identified to be associated with morphological, adaptive, and reproductive traits . The results provide important genetic resources towards understanding the molecular information associated with target traits as well as provide a foundation for using marker-assisted selection in bermudagrass breeding.

Speakers

Shuhao Yu

Oklahoma State University

Friday September 27, 2024 12:35pm - 12:45pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

12:35pm HST

PH 3 - Effects of Harvest Regimes on Shelf-life and Quality of Rabbiteye Blueberries

Friday September 27, 2024 12:35pm - 12:45pm HST

Lehua Suite

Blueberry producers in the United States are facing high input costs and labor shortages, which have led them to mechanize several areas of blueberry production, particularly harvesting. Even though the use of machine harvesters is advantageous to producers and new technologies have been developed in recent years, several parts of the process still require improvements. One of the issues caused by the adoption of mechanical harvesting is increased harvest intervals, due to the high capital expenses associated with the purchase of such machinery that in turn leads to limited availability of harvesters to perform the harvest in a timely fashion. This trend may compromise berry quality, particularly in the Southeastern United States. Firmness is a critical factor in determining consumer preference, shelf life, and market value of fresh blueberries. The postharvest quality of blueberries is influenced by various factors, including genotype, postharvest handling, and harvest conditions such as harvest intervals. This study aimed to investigate the impact of different harvest-regimes on fruit quality and storability of ‘Brightwell’ blueberries. The experiment was conducted at the Alma Blueberry Research Farm, with a randomized complete block design. Fruit were hand-harvested at different intervals: T1: every 2 days, T2: every 3 days, and T3: every 7 days. Each treatment was replicated four times, resulting in nine harvests across all treatments. Following the harvest, the berries were sorted for defects, packed in clamshells, and stored at 1°C (34°F) and 85% relative humidity. Fruit quality parameters: firmness, fruit size, color, total soluble solids (TSS), titratable acidity, and fruit rot evaluation were evaluated at four different intervals: 1, 7, 14, and 21 days after harvest. Preliminary results indicate that fruit from the second and third harvests, T1 and T2 exhibited higher firmness readings at harvest compared to T3. Throughout the storage period, the firmness of the fruit was consistently higher in T2 compared to other treatments. A bigger fruit size was obtained at the first harvest of all treatments which declined after 14 days of storage in all three treatments. At the second harvest, T2 had the highest TSS but after 21 days of storage, TSS declined and T1 had the highest TSS after 21 days of storage in all three harvests. Additionally, T3 had a higher fruit rot incidence, and wet, sunken berries in the second and third harvests. So, a harvest interval of less than 7 days is recommended to maintain the fruit quality.

Speakers

Amit Godara

The University of Georgia

Co-authors

Angelos Deltsidis

The University of Georgia

Zilfina Rubio Ames

The University of Georgia

Friday September 27, 2024 12:35pm - 12:45pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

12:45pm HST

CITR - Modifications in Existing Nitrogen Recommendations for HLB-Affected Sweet Orange Trees in Florida

Friday September 27, 2024 12:45pm - 12:55pm HST

Kahili

Florida stands as a significant player in the global citrus industry, boasting economic impacts of approximately 8.91 billion US dollars. Nevertheless, the citrus production in the state has been steadily decreasing since the onset of citrus greening (Huanglongbing, HLB) disease in 2005. Despite ongoing efforts, experts have yet to identify a potential cure for HLB, making the persistence of this disease a significant challenge for citrus production in Florida. In the wake of unavailability of a potential cure, different management strategies have been proposed aiming to minimize the HLB-induced adverse impacts on citrus plant growth and productivity and ensure the survival of citrus industry in Florida. In this context, effective nutrient management has emerged as a promising strategy for enhancing the performance of trees affected by HLB and sustaining a profitable yield. Fine root loss stands out as a primary concern in the management of HLB in citrus, as it impedes the plant's ability to uptake water and nutrients, resulting in nutritional imbalances. Effective nutrient management has the potential to effectively counterbalance the effects of fine root losses, thereby serving as a crucial factor in mitigating the adverse impacts of HLB on citrus trees. Therefore, this study has been initiated with the aim to evaluate the potential benefits of nutrient management on HLB affected mature Valencia sweet orange [Citrus sinensis (L.) Osbeck] trees. We seek to investigate the effects of different levels of nitrogen (N) i.e., 112, 168, 224, 280, 336 kg/ha on nutrient uptake, plant growth, fruit yield, juice quality, and overall performance of HLB-affected trees. In addition, nutrient mobilization in the soil in response to different levels of N has also been given critical consideration in order to evaluate the leaching potential of different nutrients and formulate mitigation strategies.

Speakers

Noor Ul Basar

University of Florida

Co-authors

Davie M Kadyampakeni

Univesity of Florida

Muhammad Adnan Shahid

Univesity of Florida

Friday September 27, 2024 12:45pm - 12:55pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

12:45pm HST

O/LT 2 - Alternate Products to Control Silvery Thread Moss in a Creeping Bentgrass Putting Green

Friday September 27, 2024 12:45pm - 12:55pm HST

Coral 2

Silvery thread moss (Byrum argenteum Hedw.) and others are considered cosmopolitan weeds of creeping bentgrass (Agrostis stoloniferous L.) golf putting greens. These putting green surfaces are vulnerable to moss infestations due to low mowing height, plant growth regulator applications, and restricted nitrogen all required for maintenance. On the actual putting surface, moss interrupts both golf ball roll and visual aesthetics. As a bryophyte, moss is a primitive photosynthetic plant without true leaves or roots and reproduce both sexually (sporophyte) and asexually (fragmentation). Early detection in putting greens is difficult because the protonema (the early stage of moss) resemble blue-green algae or Cyanobacteria. Once established, mosses can tolerate a range of environments from cool-to-hot, and wet-to-dry. Thus, mosses are a chronic problem of creeping bentgrass putting greens. In the past decade, the herbicide carfentrazone (QuickSilver; FMC Corp., Philadelphia, PA) has become the dominant strategy to suppress moss in putting greens, but requires multiple spray applications for efficacious control. In 2023 and 2024, a field study was conducted using a 25-year-old ‘L-93’ plus ‘Providence’ creeping bentgrass nursery green at North Shore Country Club (Glenview, IL). The objective was to explore moss control by two new granular products: Fiesta (chelated iron) and Castaway (tea saponin), both from The Andersons Inc. (Maumee, OH). Granular treatments at product label rate and QuickSilver at 3.35 fl oz/A were applied every 14 days for a total of 8 applications. QuickSilver was applied using a CO2-powered backpack sprayer operated at 40 psi with a three nozzle boom of XR TEEJET 8004VS applied in 2 gal water carrier/1000 sq ft. Year one evaluated granular products versus QuickSilver. Year two compared an additional standard of a once-applied spot treatment of baking soda (sodium bicarbonate) in solution. Both trials were arranged as a randomized complete block design with four replications per treatment. In 2023, Untreated, QuickSilver, Castaway, and Fiesta were evaluated. In 2024, two additional treatments were included of ½ rate Fiesta, and baking soda.. The results indicate that both Castaway and Fiesta granular products were capable of moss suppression in a putting green. Moss control with Fiesta was similar to the QuickSilver herbicide standard or spot treatment by baking soda. Therefore, these granular products could be used alone or in rotation with QuickSilver to control moss in golf course putting greens

Speakers

Shehbaz Singh

Manager of Turfgrass research, Chicago District Golf Association

Co-authors

Derek Settle

Chicago District Golf Association

Friday September 27, 2024 12:45pm - 12:55pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

12:45pm HST

PH 3 - Facilitating Postharvest Elderberry Fruit Detachment with Ethylene

Friday September 27, 2024 12:45pm - 12:55pm HST

Lehua Suite

Interest in producing elderberry (Sambucus nigra ssp. canadensis) fruit in North America has increased in recent years, including the subtropical climate of Florida. The fruit contain high amounts of antioxidants in both the juice and solid fractions and are processed into a wide variety of products. Fruit grow in clusters (cymes) of 500 or more fruit (1-2 mm diameter) each, and typically ripen at different rates, depending upon when the flowers were fertilized, the variety/selection and weather conditions. This non-uniform ripening from green to deep purple challenges growers, since unripe fruit must be removed. Delaying cyme harvest until all fruit ripen is not feasible since overripe fruit abscise before unripe fruit ripen. Fruit are typically destemmed from the cymes the day of harvest, either manually or with mechanized systems. Destemming can cause significant loss of salable product as the fruit are often crushed, releasing juice. In a series of tests, we investigated the potential to promote uniform ripening and detachment of elderberry fruit by postharvest exposure to gaseous ethylene, commercially used to initiate ripening in climacteric fruit crops. At a commercial farm in Chiefland, Florida, small segments (approximately 30 fruit each) were cut from cymes with 75% ripe fruit from three elderberry genotypes (DNS11, DNS23 and DNS36). The samples were returned to the UF Postharvest Laboratory that day, divided into two treatment groups ( /- 100 ppm ethylene) and sealed in glass jars (n=3; 3 segments/jar) at 22 °C/95% relative humidity. Jars were opened after 24, 48 and 72 hr to avoid CO2 accumulation; at each timepoint, one jar was removed and fruit examined; remaining jars were resealed and ethylene concentration was reestablished. Exposure to ethylene significantly increased ripe fruit detachment after 24 hr, however partially ripe fruit ripened after 48 hr, irrespective of treatment. Fruit juice content was 46%, pH=5.0. Ethylene did not affect the following parameters, although there were differences in germplasm: soluble solids content (7-14%), total titratable acidity (0.44-0.70%), and total anthocyanin content (8-20 mg · g-1). Attached or detached fruit lost 6-10% weight after 24 hr, whereas stems lost about 50% weight; after 48 hr, shrivel symptoms appeared and weight loss roughly doubled for these same groups. Consideration must be given as to exposure to ethylene for 24 hr for easy fruit removal versus holding for 48 hr for ripening with accompanied higher weight loss and shriveling.

Speakers

Steven Sargent

University of Florida

Professor and Extension Postharvest Specialist

Co-authors

Adrian Berry

University of Florida

Ali Sarkhosh

University of Florida

David Jarnagin

Hydemoer Co.

Kevin Athearn

University of Florida

Friday September 27, 2024 12:45pm - 12:55pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

12:45pm HST

VSF 2 - Assessing the Viability of Olive Trees as an Alternative Fruit Crop for Cultivation in Florida

Friday September 27, 2024 12:45pm - 12:55pm HST

South Pacific 3

Over the past decade, the cultivation of olive trees (Olea europaea) in Florida has experienced remarkable growth, expanding tenfold. Currently, there are more than 60 growers tending to approximately 800 acres spread across 26 counties in Florida. Despite this significant expansion in Florida’s olive tree cultivation, accompanied by a surge in global olive oil demand, research in this area has been lacking. To address this gap, comprehensive data collection commenced in the summer of 2023 through three distinct trials located in Jay, Wauchula, and Fort Pierce, Florida. These trials aim to determine the most productive olive tree varieties and optimal cultivation techniques tailored to Florida’s diverse climate and soil compositions. Given variations in grove management approaches and tree maturity levels, a range of cultivars representing different genotypes were being tested across various locations. The cultivar ‘Arbequina’ was consistent across all trials. In addition to ‘Arbequina’, other cultivars such as ‘Koroneiki’ and ‘Sikitita’ were assessed in Wauchula, while ‘Lecciana’ and ‘Sikitita’ were examined in Fort Pierce. Throughout the trials, parameters including soil fertility, temperature, soil moisture levels, as well as leaf nutrient status and phenological observations were quantified twice a year. No nutrient deficiencies were detected in either soil or leaf samples, but also no consistent patterns regarding flowering or production were observed. The ongoing data collection is expected to shed light on critical aspects regarding the feasibility of olive tree cultivation within the Florida environment and provide valuable insights for growers and stakeholders.

Speakers

Lorenzo Rossi

Associate Professor, University of Florida

Dr. Rossi’s research program focuses on improving root health and growth on cultivated crops, leading to the development of environmentally sound and effective management methods. He is a horticulturist with specific expertise related to plant stress physiology, root dynamics and... Read More →

Co-authors

Alejandro Bolques

Florida A

Audrey Beany

UF/IFAS/IRREC

Davie Kadyampakeni

University of Florida

John-Paul Fox

University of Florida

Michael Garcia

Florida Olive Council, LAA

Friday September 27, 2024 12:45pm - 12:55pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

12:55pm HST

CITR - Evaluating the Impact of Fabric Mulch Ground Cover on Grapefruit Tree Growth and Soil Characteristics in the Indian Rive

Friday September 27, 2024 12:55pm - 1:05pm HST

Kahili

Florida citrus production and acreage have drastically decreased in the past years primarily due to citrus greening disease; consequently, citrus grove management has become more challenging and resource demanding. To increase soil health and restore tree and root health, new management practices have been implemented; in particular, a practice that has increased in use in the Indian River region is fabric mulch ground cover (FMGC). Potential advantages of FMGC include improved weed and pest control, reduced soil erosion, increased soil moisture and nutrient retention, reduced temperature extremes, and enhanced microbiome composition of the soil. Although the practice has been in use for almost ten years, little data has been scientifically collected from established groves. Hence, the goal of this trial is to evaluate the effects of FMGC on grapefruit tree growth and soil characteristics in the Indian River region. Four-year-old ‘Star Ruby’ (Citrus × paradisi) grapefruit trees grafted on ‘US-942’ (Citrus reticulata × Poncirus trifoliata) rootstock grown with or without FMGC were uniformly chosen for a two-year trial. A total of 20 trees were assigned to two treatments (FMGC vs. conventional). Leaf and soil nutrients, trunk diameter, height, canopy volume, and soil microbiome composition have been collected in the winter and summer. Gathered data showed initial differences in canopy volume, trunk diameter, and soil moisture between the two treatments. The trial will continue for an additional year, resulting in a greater understanding of the impact of this recently implemented management practice and its potential benefits to Florida citrus growers.

Speakers

Audrey Beany

Biological Scientist, University of Florida

Co-authors

John-Paul Fox

University of Florida

Lorenzo Rossi

University of Florida

Robert Adair

Florida Research Center for Agricultural Sustainability, Inc

Friday September 27, 2024 12:55pm - 1:05pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

12:55pm HST

O/LT 2 - Evaluation of Gypsum and Fertilizers for Enhanced Bermudagrass Performance Under Salinity Conditions in Florida Sandy Soils

Friday September 27, 2024 12:55pm - 1:05pm HST

Coral 2

Coastal regions, facing saltwater intrusion due to overpumping, exacerbate challenges for turf managers facing soil salinization, and sodium and bicarbonate hazards. Given the prevalence of gypsum applications to counter sodium hazard and the utilization of acidifying fertilizers for neutralizing bicarbonate hazards, there is a need to comprehensively evaluate the effectiveness of these strategies in alleviating soil salinity and bicarbonate hazards and their impact on turfgrass performance. An 8-week study was conducted at the University of Florida’s Fort Lauderdale Research and Education Center to assess the impact of ammonium sulfate and calcium nitrate, either alone or in combination with gypsum, on turfgrass performance and soil properties of a ‘Celebration’ bermudagrass fairway under salinity conditions. To replicate high salinity conditions, table salt (NaCl) was applied to half of the area at a rate of 5 lb of NaCl 1000 ft-2, with the rest of the area serving as a control. Gypsum was applied at a rate of 230 lb gypsum 1000 ft-2 and divided in two applications at mid-point (week 3) and prior to completion of the study (week 7). Fertilizers were applied at a rate of 0.5 lb N/1000 ft2. Salt and fertilizer were applied every two weeks, alternating between each other, for a total of four applications each. Experimental design was a split-split-split design with four replications, with salt serving as a main plot, gypsum as a sub-plot and fertilizer treatment as a sub-sub-plot. Turfgrass visual quality (1=worst, 9=best), normalized difference vegetation index (NDVI), percent green cover, and dark green color index (DGCI), turf injury, volumetric water content (VWC) and electrical conductivity (EC) were assessed weekly. Gypsum had no effect on turfgrass performance. Plots fertilized with AMS initially showed a higher quality than plots fertilized with calcium nitrate after fertilization, however no differences were found toward the end of the trial. Salt reduced turfgrass quality, NDVI and percent green cover and resulted in turfgrass injury, particularly following initial applications. However, it appears that the turfgrass gradually adapted to the salinity conditions, as turfgrass injury from salt decreased during the second half of the experiment. Volumetric water content and EC were affected by the interaction of salt and gypsum. During the experiment, plots treated with gypsum and salt consistently exhibited higher VWC and EC compared to plots that did not receive gypsum. Results suggest that disproportioned amounts of gypsum to improve turfgrass performance applied to golf courses are not justified.

Speakers

I. Alejandra Sierra

University of Florida

Co-authors

Marco Schiavon

University of Florida

Friday September 27, 2024 12:55pm - 1:05pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

12:55pm HST

PH 3 - Integrated Analyses of Transcriptomics and Lipidomics Reveal Potential Mechanisms Related to Physiological Disorders of

Friday September 27, 2024 12:55pm - 1:05pm HST

Lehua Suite

Hardy kiwifruit (Actinidia arguta) is highly sensitive to low temperatures, which can cause chilling injury (CI) as a physiological disorder. Peel surface pitting with black/dark brown spots was developed as CI symptoms in cold-stored hardy kiwifruit. In this study, we performed transcriptomic and lipidomic analyses to elucidate the potential mechanism of CI symptoms in cold-stored hardy kiwifruit. The peel tissues of hardy kiwifruit were collected after harvest (HV) and after cold storage; pitted peel tissues from CI-damaged fruit (PT) and healthy peel tissues from CI-unaffected fruit (HT) were also collected. Transcriptomic analysis identified 10,612 differential expressed genes (DEGs) between HV and HT tissues, and 3,206 DEGs were detected between HT and PT tissues. Among the 3,206 DEGs, 1,322 transcripts were up-regulated in HT tissues, while 1,874 transcripts were up-regulated in PT tissues. The KEGG pathway enriched by up-regulated DEGs in HT indicated protein modification, L-valine degradation, and polyol metabolism, while up-regulated DEGs in PT enriched alkaloid biosynthesis, protein modification, and lipid metabolism. In lipidomics analysis, a total of 101 lipids clustered into 14 subgroups were detected in peel tissues of cold-stored hardy kiwifruit. Based on the results of VIP scores (> 1.5), the levels of triacylglycerol (TAG) 54:8, TAG 54:9, phosphatidylcholine (PC) 36:4, PC 34:2, PC 36:5, PC 34:3, and TAG 54:7 were higher in PT tissues, but the levels of phosphatidylethanolamine (PE) 36:2, phosphatidylserine (PS) 38:3, PS 36:0, PC 36:1, PE 34:1, and PE 36:1, were higher in HT tissues, compared with the other tissues. Therefore, the results indicated that the CI symptoms in cold-stored hardy kiwifruit would be derived from integrated transcriptomic and lipidomic results.

Speakers

Hyowon Park

Ph.D candidate, Chung-Ang University

Co-authors

Hyun Ji Eo

National Institute of Forest Science

Jane E. Stewart

Colorado State University

Jinwook Lee

Professor, Chung-Ang University

Jorge R. Ibarra Caballero

Colorado State University

Uk Lee

National Institute of Forest Science

Friday September 27, 2024 12:55pm - 1:05pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

12:55pm HST

VSF 2 - A Comparative Study of Ripening Timelines in Haskap (Lonicera caerulea L.) Cultivars.

Friday September 27, 2024 12:55pm - 1:05pm HST

South Pacific 3

Haskap (Lonicera caerulea L.), also known as edible blue honeysuckle or honeyberry, is a new and emerging berry crop in North America. Its resilience to cold temperatures, adaptability to various soil pH levels, distinctive flavor, and health benefits make it suitable for cultivation in colder climates. The period from flowering to fruit ripeness is remarkably brief in haskap, typically ranging from six to eight weeks, offering an advantageous alternative in shorter-growing regions. Yet, detailed guidance on its cultivation and fruit quality is scarce. To aid growers, a two-year study at the Western Agricultural Research Center assessed the ripening timelines of 15 haskap varieties, providing critical data to optimize harvest timing and management practices. Throughout the growing seasons of 2022 and 2023, from May through August, fruit quality and ripening stages were closely monitored two to three times a week by collecting berry samples. From these samples, traits such as total soluble solids content (Brix), pH, total acidity (TA), single berry mass, and berry color changes were measured. Assessment of this phenotypic data revealed distinct patterns for each trait across the different varieties studied. Cultivars such as 'Blue Goose', 'Boreal Beauty', and 'Sugar Mountain Blue' reached their harvest readiness sooner, around approximately 650 growing degree days (GDD) for the year, followed by a reduction in berry size due to water loss and a rise in sugar concentration. In contrast, Aurora, Tana, and Kawai matured more slowly, achieving peak ripeness near ~1000 GDD. Yet, they preserved their mature fruit characteristics (consistent berry weight and sugar levels) through the sampling period’s end. These insights into the ripening patterns of haskap varieties from prominent breeding programs in North America can inform growers as they choose specific cultivars and decide on optimal harvest times.

Speakers

Venkateswara Rao Kadium

Montana State University

Co-authors

Andrej Svyantek

Montana State University

Zach Miller

Montana State University

Zhuoyu Wang

Montana State University

Friday September 27, 2024 12:55pm - 1:05pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

1:05pm HST

CITR - High-throughput Phenotyping and Fruit Juice Quality of 'OLL-8' Sweet Orange Scion on Different Rootstocks with Comparison of Oxytetracycline Injections

Friday September 27, 2024 1:05pm - 1:15pm HST

Kahili

The Florida citrus industry has seen a 90% decline in fruit production, following the first identification of huanglongbing (HLB) in 2005. Sweet orange (Citrus sinensis) cultivars make up a majority of the juice industry and are known to be susceptible to HLB; therefore, new tolerant or resistant cultivars or crop protection treatments need to be explored. Of the sweet orange cultivars released by UF Institute of Food and Agricultural Sciences, ‘OLL’ lines have shown some potential tolerance to this disease in cultivar field trials. High-throughput phenotyping revealed that nearly 14% of top performing trees across roughly 90 different research blocks in Florida, were accessions derived from the original ‘OLL’ tree. Of these trees, ‘OLL-8’ represents 11% of top performing trees across these different research blocks. This research explores the effects of different rootstocks in combination with the ‘OLL-8’ scion. Three UF rootstocks (‘UFR-2’, ‘UFR-4’ and ‘UFR-6) and three industry standard rootstocks (‘US-897’, ‘US-942’ and ‘Swingle’) were compared. For each rootstock, 12 mature trees, across three different blocks were compared across three different time intervals during the 2023 and 2024 ‘Valencia’ harvest seasons at a field trial in Lake Alfred, Florida. In 2024, the same 12 mature trees per rootstock were compared with trees that received oxytetracycline injections following the previous harvest season. Data was collected on juice quality variables including total soluble solids, titratable acidity in citric acid equivalents, sugar:acid ratio, pounds solids per box, percent juice, and color as well as on external fruit quality data parameters such as mass, diameter, length, and color. Data were analyzed to determine statistically significant differences among the different rootstocks evaluated. To determine differences in tree health, high-throughput phenotyping via drone flight occurred in December of 2023 and March of 2024 and included variables such as tree count, measurements of canopy area and volume, normalized difference vegetation index (NDVI), and normalized difference red edge index (NDRE). There was evidence for statistically significant differences for various traits among the rootstock combinations evaluated in this study.

Speakers

Emily Worbington

University of Florida-IFAS CREC

Co-authors

Heaven Heflin

University of Florida/IFAS-Citrus Research and Education Center

Joe Volpe

University of Florida

John Chater

University of Florida

Friday September 27, 2024 1:05pm - 1:15pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

1:05pm HST

O/LT 2 - Cold-hardiness, Flowering, and Disease Resistance of 24 Camellia Cultivars and Selections in Tennessee, USA

Friday September 27, 2024 1:05pm - 1:15pm HST

Coral 2

Cold hardiness, flowering, and disease resistance of ornamental camellia (Camellia spp.) cultivars are poorly documented when grown in a climate subjected to occasional -18°C (0°F) temperatures. To comprehensively understand cold-hardiness, flowering, and disease resistance, 24 cultivars and selections of camellia species and hybrids were evaluated in McMinnville, TN, USA (USDA Hardiness Zone 7a). Camellias were planted in field plots in Mar 2011, evaluated for flowering from year 2011 to 2020, and rated for low-temperature damage in 2014 and 2023. The Camellia Yellow Mottle Virus, monochaetia leaf spot (Monochaetia sp.), edema, flower blight (Ciborinia camelliae), and flower spot (Botrytis cinerea) severity (% affected) were evaluated from Oct to Nov in 2016 and 2017, and the season-long area under the disease progress curve (AUDPC) was calculated. ‘April Remembered’, ‘April Rose’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Carnival’, ‘Autumn Spirit’, ‘Elaine Lee’, ‘Survivor’, and a C. chekiangoleosa selection were least affected by low winter temperatures, whereas ‘Korean Snow’, ‘One Alone’, a C. sasanqua selection, ‘Pink Icicle’, and ‘Shishigashira’ were severely damaged. Cultivars that flowered most reliably (5 to 6 of 8 years) included ‘Arctic Snow’, ‘April Remembered’, ‘April Rose’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, and ‘Survivor’, whereas ‘Maroon Mist’, ‘One Alone’, and ‘Shishigashira’ never flowered. ‘Korean Fire’, ‘Classic Pink’, ‘Maroon Mist’, and ‘Spring’s Promise’ displayed the highest virus severity and AUDPC. ‘Arctic Snow’, a C. sasanqua selection, and a C. chekiangoleosa selection had no viral symptoms. A C. sasanqua selection and ‘Red Aurora’ were significantly impacted by edema disorder, with severity ratings of ∼43% and 26%, respectively. Monochaetia leaf spot severity was highest in ‘Red Aurora’ and ‘Spring’s Promise’, whereas ‘Anacostia’, ‘Arctic Snow’, ‘Ashton’s Ballet’, ‘Autumn Spirit’, ‘Classic Pink’, ‘Kuro Delight’, ‘One Alone’, ‘Pink Icicle’, ‘Shishigashira’, and ‘Survivor’ exhibited the least monochaetia leaf spot severity and AUDPC. Flower blight and flower spot were observed only in ‘Arctic Snow’ and ‘Survivor’. These findings will aid landscapers and nursery growers with selecting and managing camellia cultivars effectively.

Speakers

Jacob Shreckhise

USDA-ARS, U.S. National Arboretum

Co-authors

Donna Fare

USDA-ARS, U.S. National Arboretum (Retired)

Fulya Baysal-Gurel

Tennessee State University

Madhav Parajuli

USDA-ARS, U.S. National Arboretum

Friday September 27, 2024 1:05pm - 1:15pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

1:05pm HST

PH 3 - β-Cyclodextrin Nano-encapsulated Carvacrol Inclusion Complexes Improve Postharvest Quality of Limes

Friday September 27, 2024 1:05pm - 1:15pm HST

Lehua Suite

The ripening and senescence of fresh fruit and vegetables are inevitable during storage, transportation, and sale, which will reduce their marketability and cause substantial economic losses. The infection of pathogenic microorganisms can also lead to food safety problems. Plant essential oils are considered a promising strategy to preserve fresh produce. However, their application is limited by several aspects, including high volatility, low solubility, off flavor, etc. Encapsulation technology has emerged as a promising solution to alleviate these limitations. Nanoencapsulation is a delivery system for bioactive compounds that is usually employed to support the stability of the agents, maximize their retention, and control the release of the compounds at the target locations. A nanoemulsion composed of carvacrol and β-cyclodextrin was prepared by an ultrasound-mediated method, and the encapsulation process was conducted using a Buchi® Nano Spray Dryer B-90. The inclusion complex powder was collected and filled to air-permeable sachets. The sachets were then fixed inside commercial clamshells containing limes to simulate shelf-life. Fruit quality and total microbial population were analyzed. The results showed that the dimensions of spray-dried powders were primarily at nanoscale. The encapsulation process did not affect the antimicrobial and antioxidant activities of carvacrol. The nanocapsules prolonged the release of carvacrol. It effectively delayed the rapid color deterioration of limes without causing phytotoxicity, and maintained lime quality with higher firmness and lower weight loss. Free carvacrol and carvacrol/β-cyclodextrin treatments significantly reduced the growth of P. digitatum and total bacteria on fruit peel and inside of the wounds. However, the GC-MS results showed carvacrol residue detected from free carvacrol-treated fruit, but not from the carvacrol/β-cyclodextrin-treated fruit. The results indicate that nano-encapsulated carvacrol/β-cyclodextrin inclusion complexes can be applied as an effective strategy to preserve postharvest produce. Keywords: Nanoencapsulation, nano spray drying, essential oil, postharvest quality, lime

Speakers

Chang Shu

USDA-Agricultural Research Service-Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center

Co-authors

Xiuxiu Sun

USDA-Agricultural Research Service-Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center

Friday September 27, 2024 1:05pm - 1:15pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

1:05pm HST

VSF 2 - Assessment of Botrytis Fruit Rot Susceptibility in Selected Strawberry Cultivars under Field Conditions

Friday September 27, 2024 1:05pm - 1:15pm HST

South Pacific 3

Botrytis fruit rot (BFR) or grey mold disease, caused by Botrytis cinerea Pers., poses a significant threat to strawberry crop production in the mid-Atlantic region of the U.S. The extensive use of fungicides to combat this fungal disease has resulted in listing the strawberries in the Dirty Dozen fruits and the evolution of fungal strain resistance to fungicides. Hence, exploring potential alternative strategies is crucial to reducing pesticide use and minimizing BFR; as such, utilizing resistant plant cultivars is a potential strategy. With this, the current study aimed to assess the susceptibility of two cultivars to Botrytis, Flavorfest, and Honeoye, which showed resistance to gray mold under in vitro conditions, and compare them with grower standard cultivars, Chandler and Sweet Charlie, under field conditions. The field evaluations were conducted at two locations during the 2022-2023 growing season: Hampton Roads Agriculture Research and Extension Center in Virginia Beach, VA, and a grower farm in Fredericksburg, VA. Transplanting of plants was done on October 12, 2022, in Fredericksburg and October 17, 2022, in Virginia Beach. A randomized complete block design was used in the experiments with four replicates per cultivar in Virginia Beach and three replicates in Fredericksburg, and each replicate had 12 plants. Fruits were harvested twice a week throughout the season to assess BFR occurrence and marketable crop yield. The main effect of the cultivar was significant for Botrytis fruit rot and marketable yield for the season. 'Honeoye' showed the lowest BFR-infested fruits (~6.5 g of fruits/plant), compared to 'Chandler' (22.5 g). However, 'Chandler' showed the highest marketable yield (713 g/plant), followed by 'Sweet Charlie' (473 g), while 'Flavorfest' (261 g) and 'Honeoye' (216 g) produced the lowest yields. Additionally, marketable yield differed by location, with higher yields recorded in Virginia Beach. Post harvest parameters including fruit firmness, total soluble solids (TSS), and pH that were measured on a subsample of fruits in Virginia Beach showed significant cultivar effect . ‘Honeoye’ had the least firm fruit but had the highest TSS for the season, not different than ‘Sweet Charlie’. The fruit pH of ‘Sweet Charlie’ was the highest. Information on resistant cultivars could assist growers in choosing appropriate cultivars to meet their farm production practices.

Speakers

Jayesh Samtani

Associate Professor, Virginia Tech

Co-authors

Amaranatha Vennapusa

Delaware State University

Baker Aljawasim

Virginia Tech

George Snead

Braehead Farm, Inc.

Kalpalatha Melmaiee

Delaware State University

Patricia Richardson

Virginia Tech

Friday September 27, 2024 1:05pm - 1:15pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

1:15pm HST

CITR - Assessing Tree and Root Responses of Various HLB-affected Citrus Cultivars Using Oxytetracycline Trunk Injections

Friday September 27, 2024 1:15pm - 1:25pm HST

Kahili

The citrus industry across the globe, including Florida, has been severely affected by the citrus greening disease (Huanglongbing, HLB), which is associated with the bacterium Candidatus Liberibacter asiaticus (CLas) and vectored by the Asian citrus psyllid. While no single method has been found to completely control CLas, ways to mitigate its effects on citrus trees have been increasingly studied. One recent management method that has been attracting attention is oxytetracycline (OTC) trunk injections. While initial research has shown that OTC trunk injections have been able to reduce HLB symptoms, there have been some inconsistencies about the extent of that reduction between different cultivars. A limited number of cultivars have been studied, mainly focusing on the sweet oranges ‘Valencia’ and ‘Hamlin’. The limited cultivars injected that are closely genetically related may cause differences in the effectiveness of treatment. There is a gap in knowledge about how OTC treatments affect cultivars with diverse genetic backgrounds. The aim of this study was to investigate the effects of OTC trunk injections on above and belowground tree health of various United States Department of Agriculture developed citrus cultivars. A completely randomized experimental design comprising 10-year-old mandarin, grapefruit, and sweet orange-like cultivars grafted on ‘US-942’ and ‘US-812’ rootstocks was used to study OTC trunk injection rates applied once a year at the recommended label concentrations (n = 21). Similarly, trees from the same cultivars grafted on the same rootstocks not receiving any injections were used as controls (n = 21). Throughout the experiment, above and belowground components were analyzed for any changes. Aboveground measurements included tree health within and between cultivars: canopy dimensions, leaf CLas titer, fruit size, drop and harvest count, and OTC residue in leaves. Belowground measurements included analysis of root and microbiome health by observing root density, root CLas titer, root OTC residue, and microbiome population diversity. The results are helping researchers to utilize OTC trunk injections more effectively.

Speakers

Giancarlo Buzzi

University of Florida

Co-authors

Lorenzo Rossi

University of Florida

Matthew Mattia

US Department of Agriculture

Friday September 27, 2024 1:15pm - 1:25pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

1:15pm HST

O/LT 2 - The American Rose Trials for Sustainability® (A.R.T.S.®) Program Announces Five Winning Roses for 2025

Friday September 27, 2024 1:15pm - 1:25pm HST

Coral 2

The American Rose Trials for Sustainability® (A.R.T.S.®) is a US rose trialing program in its eighth year of announcing winning roses. A.R.T.S.® evaluates newer roses in the marketplace using scientific methodology (blocking, randomization, control cultivars, etc.). Roses are evaluated over two growing seasons and are grown using minimal inputs (i.e. no pesticides, no deadheading, etc.). Entries that score equal to or higher than the control cultivars (Double Knock Out® [‘RADtko’] and Sunrise Sunset™ [‘BAIset’]) and have >50% survival by the end of the trial period, earn regional Local Artist awards. Roses winning in four or more Köppen climate regions earn Master Rose awards. The 2025 award winning roses were planted in 2022. Data was collected monthly during the 2022 and 2023 growing seasons on floral attributes (42.5% of score), foliar health and quality (45% of score), and growth habit (12.5% of score). There were six trial sites representing five US Köppen climate regions (Cfa, Csa, Dfa, Dfb, and H). Five roses won 2025 A.R.T.S.® Local Artist awards: Arctic Blue™ (‘WEKblufytirar’; Csa), Easy to Please™ ('WEKfawibyblu'; Cfa), Pretty Polly® Lavender (‘ZLEpolthree’; Dfa), Sunset Horizon™ (‘MEIsistoma’; Dfa and Dfb), and True Bloom™ True Friendship™ (‘ALTmine’; Csa and Dfa). Performance data will be provided by region for the two control and five winning rose cultivars.

Speakers

Kristine Lang

Assistant Professor and Extension Specialist, South Dakota State University

Co-authors

David Zlesak

University of WI River Falls

Gaye Hammond

Houston Rose Society

Gregory Pongetti

Arboretum and Botanical Garden at Cal State Fullerton

Jeff S. Kuehny

LSU AgCenter Botanic Gardens at Burden

Jessica Clonninger

Boerner Botanical Gardens

Jessie Liebenguth

Reiman Gardens-Iowa State University

Patrick Dahl

Chicago Botanic Garden

Randy S. Nelson

University of Minnesota- Crookston

Richard Hawke

Chicago Botanic Garden

Shaun Moser

Conservation Garden Park

Steve George

Texas A

Susan Worthey

Magnolia Botanical Garden- Mississippi State University

Wanda E. Ellis

LSU AgCenter Botanic Gardens at Burden

Friday September 27, 2024 1:15pm - 1:25pm HST
Coral 2

Poster presentation (individual talk), Ornamentals/Landscape and Turf 2

SUBJECT Ornamental Landscape Turf

1:15pm HST

PH 3 - Nondestructive Detection of Chilling Injury Based on VIS/NIR Spectroscopy in Sweet Potato

Friday September 27, 2024 1:15pm - 1:25pm HST

Lehua Suite

Sweet potato (Ipomoea batatas L.) is one of the seven major food crops grown worldwide. The optimal storage temperature for sweet potatoes is 12-15℃, and chilling injury occur when it falls below 10℃. The initial symptom of chilling injury in sweet potatoes is difficult to discern in visual judgment and requires checking through a cut-off sections. Therefore, this study intended to develop a non-destructive chilling injury prediction model using VIS/NIR spectroscopy sensors. USB4000 Fiber Optical Spectrometer was used for collecting spectrum data in the wavelength of the visible to near-infrared region (400 nm to 1100 nm), and the average value was used by measuring six areas divided into upper, middle, and lower parts to reduce errors. Firmness, total soluble solids, internal chromaticity, chilling index, and Malondialdehyde (MDA) were measured as reference data, and Partial Least Squares Regression(PLSR) method was used for prediction. To increase the accuracy of the model, the near-infrared spectrum data were preprocessed using the Savitzky–Golay 1st and 2nd derivatives (S–G), standard normal variate (SNV), and multiplicative scattering correction (MSC) methods. Excellent performance models for each preprocessing methods were selected, and as a result of verification through the prediction model, the 'Hogammi' variety showed excellent performance in the preprocessing of Savitzky-Golay 2st derivative in TSS and Malondialdehyde (MDA), and CI index showed the best performance in the processing of SNV. As indicators of chilling injury such as the CI index involve subjective opinions of experimenters, the findings of this study could be used as a fundamental step to develop more objective and accurate chilling injury prediction models by including various internal indicators.

Speakers

jonghwan lee

kangwon national university

Co-authors

CheonSoon Jeong

kangwon national university

HanRyul Choi

National Institute of Horticultural and Herbal Science

MinWoo Baek

kangwon national university

SeMin Jang

kangwon national university

Shimeles Tilahun

kangwon national university, jimma university

SuHo Tae

kangwon national university

Friday September 27, 2024 1:15pm - 1:25pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 3

SUBJECT Postharvest

1:15pm HST

VSF 2 - Effects of Chitosan and Ultraviolet A (UVA) Light on Postharvest of Blackcurrant Fruit

Friday September 27, 2024 1:15pm - 1:25pm HST

South Pacific 3

Blackcurrant (Ribes nigrum L.) is a small fruit known for its health benefits, but treatment effects on postharvest storage for fresh markets remains understudied compared to other berries, such as blueberry (Vaccinium spp.). This work aims to identify the effect of chitosan coating, ultraviolet a (UVA) light, and combined UVA-Chitosan treatments on blackcurrant postharvest storage. Physical (weight loss and firmness) and physiochemical analyses (soluble solid content, pH, citric acid content, and ascorbic acid content) were combined with microbial population quantification, phenolic compound characterization, and antioxidant capacity assessment. Samples were evaluated every three days of storage throughout this experiment. The results indicated that chitosan treatments have positive effects on reducing berry weight loss, maintaining berry firmness, and reducing mold populations. UVA influenced certain bioactive compounds, such as cyanidin-3-galactoside and rutin. The interaction effects from these two treatments were minimal. This study provides important information for blackcurrant postharvest storage and further small fruit storage work, considering both UVA and chitosan had differential beneficial effects on blackcurrant berries’ physical and chemical attributes.

Speakers

Venkateswara Rao Kadium

Montana State University

Co-authors

Andrej Svyantek

Montana State University

Aude Watrelot

Iowa State University

Zachariah Miler

Montana State University

Zhuoyu Wang

Montana State University

Friday September 27, 2024 1:15pm - 1:25pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

1:25pm HST

CITR - Insights from a Citrus Breeding Program: Leveraging the Citrus Genome Database and Breeding Information Management System

Friday September 27, 2024 1:25pm - 1:35pm HST

Kahili

Citrus is one of the most valuable fruit crops globally and Florida historically has been known to be the major state producing sweet oranges for juice. Continuous efforts to develop new scion and rootstock varieties have been on-going in the University of Florida Citrus Breeding Program since the 1980s. Over the years numerous phenotypic data sets including big data from image-based phenotyping and large genotypic data sets from advances in sequencing technology have been generated. Efficient tools for data collection and management of both phenotypic and genotypic information are needed. To facilitate citrus breeding in Florida and elsewhere, the Citrus Genome Database (CGD, www.citrusgenomedb.org) has developed a Breeding Information Management System (BIMS) to store, manage, and analyze the phenotype and genotype data of private breeding programs. BIMS is compatible with Field Book, an Android App that allows for collection of phenotype data in a digital notebook on a tablet or phone. As a participant of the 2022-funded SCRI-project ‘Advanced National Database Resources for Specialty Crop Research and Improvement’, the UFL Citrus Breeding Program has adopted BIMS. This poster demonstrates the value of moving to electronic data collection using Field Book and the web-based management system BIMS. The goal of the UF breeding program for this project is to work together with citrus breeding programs across the U.S. and provide training on how to use BIMS and Field Book as well as adapt these tools to meet the needs of citrus breeders.

Speakers

Ronald Tapia

University of Florida/IFAS Citrus Research and Education Center

Co-authors

Bryan Ellerbrock

Clemson University

Dorrie Main

Washington State University

Frederick Gmitter

University of Florida/IFAS Citrus Research and Education Center

Jodi Humann

Washington State University

Sook Jung

Washington State University

Taein Lee

Washington State University

Trevor Rife

Clemson University

Friday September 27, 2024 1:25pm - 1:35pm HST
Kahili

Poster presentation (individual talk), Citrus Crops

SUBJECT Citrus

1:25pm HST

PH 3 - Development and Characterization of Bio-based Nanoparticle Coatings from Sweetpotato Peels

Friday September 27, 2024 1:25pm - 1:35pm HST

Lehua Suite

Bio-based nanoparticle coatings were developed using nanomaterials extracted from sweetpotato peels and combined with other biopolymers to reduce postharvest deterioration of sweetpotato roots and other fresh produce items. The sustainable coating materials applied as thin films to the surface of washed sweetpotato roots reduced postharvest deterioration, weight loss, and respiration rate, while maintaining root market quality. Chemical and physical characterization was made of the cellulose nanomaterials (CNMs), pectin, and phenolic compounds from ‘Beauregard’ sweet potato peel tissue. The peel contained 40.2% cellulose, 19.1 % lignin, 10.8% hemicellulose and 29.8% pectin. The extracted CNMs from the peel tissue showed a high degree of crystallinity, particularly for cellulose nanocrystals. The CNMs and pectin fractions formed stable water dispersions with strong shear thinning behavior suitable for coating application. The thin films formed by the CNMs and pectin fractions exhibited an entangled fiber network structure with significantly reduced water and gas permeability. Our results demonstrated the feasibility of using sweetpotato peel tissue as an integral component in a bio-based nanoparticle film coating.

Speakers

David Picha

Louisiana State University Agricultural Center

Co-authors

Qinglin Wu

LSU Agricultural Center

Ragab Abouzeid

School of Plant, Environmental and Soil Sciences

Friday September 27, 2024 1:25pm - 1:35pm HST
Lehua Suite

Poster presentation (individual talk), Postharvest 2

SUBJECT Postharvest

1:25pm HST

VSF 2 - Biostimulants Did Not Influence Strawberry Yield but Increased Fruit Sugar Content

Friday September 27, 2024 1:25pm - 1:35pm HST

South Pacific 3

In the past few years, there has been an increased interest in the use of biostimulants for improved crop production. Biostimulants are products that can promote plant growth when applied in amounts so small that they do not provide much nutrition. These are composed of different organisms, compounds or plant extracts; they include beneficial fungi and bacteria, humic and fulvic acid, seaweed extracts, and protein hydrolysates. During the 2022-23 growing season we evaluated three different biostimulant products in annual hill strawberry plasticulture production. ‘Ruby June’ plants were transplanted on 24 Oct, 2022 on non-fumigated beds and were maintained as per grower standard practices. Treatments were as follows (i) no biostimulant (ii) preplant AminoSalmon (247 kg/ha) applied during bed making (3) plugs dipped for 20 seconds in TerraGrow Liquid (TGL, 3ml/38 L) prior to transplanting followed by a foliar spray and a drip application (1.5L/ha) at one, fourteen, and thirty days after transplanting, resuming monthly during spring; and (iv) EZ-GRO 16-0-0 (3.9 kg/ha) drip application 14 days after transplanting and every 14 days during fall, resuming during spring. All non-treatment irrigation valves were closed during treatment injection through the drip lines. Ripe fruit was harvested beginning 31 March and continued twice a week until 16 June. Harvested fruit was categorized into marketable and non-marketable yield by replicate and fruits were weighed for each category. Yields were cumulated for the season and expressed as g/plant for data analysis. For total yield and marketable yield, no treatment differences were found. Fruit size was estimated as g/fruit by weighing 10 marketable fruits weekly. Five marketable fruits were measured weekly for firmness using a texture analyzer then stored at -20 °C for later analysis of pH and total soluble solids (°Brix) using a digital refractometer. While fruit firmness and pH were not influenced by treatments, the application of both the amino salmon and EZ-GRO biostimulants significantly improved total soluble solids values compared to the untreated control.

Speakers

Jayesh Samtani

Associate Professor, Virginia Tech

Co-authors

Baker Aljawasim

Virginia Tech

Guillaume Pilot

Virginia Tech

Patricia Richardson

Virginia Tech

Friday September 27, 2024 1:25pm - 1:35pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

1:30pm HST

MKEC - Identifying the Ideal Combination of Strawberry Variety and Climate Control for Greenhouse Cultivation in Michigan

Friday September 27, 2024 1:30pm - 1:40pm HST

South Pacific 2

Strawberries are among the most popular fruits consumed in Michigan. However, Michigan's climate conditions hinder local production on a commercial scale. Outside of the summer period, production is only viable through controlled environment cultivation. Consequently, local demand relies on shipments from other U.S. producing regions, such as California and Florida, or imports mainly from Mexico. Given the delicate nature of this fruit, the long-distance supply chain can compromise the quality of the fruit, leading to substantial losses at retail and consumer levels. These factors drive the need to identify strategies to extend strawberries production season and empower a resilient regionalized supply chain. Our study aimed to optimize economic returns of greenhouse strawberry growers in Michigan using a bioeconomic modeling approach. Three strawberry varieties, namely Albion, Cabrillo, and Monterey, were grown in a greenhouse utilizing five different temperature treatments. The temperature treatments employed during the day and night cycles were set as 15/7° C, 10/18° C, 21/13° C, 24/16° C, and 27/19° C, respectively. Data was collected on productivity per plant and transplanted into a commercial grower scenario. The spatial-temporal bioeconomic model simulated the implementation of 15 hypothetical greenhouses, each covering an area of 1,000 m2, to accommodate one variety and one treatment at the time. Using a partial budget analysis, the research identified profitability capacity for greenhouse strawberry cultivation. From a costing perspective, the model considered the most important operating costs, including energy consumption by supplemental lighting and heating systems, labor requirements, materials (runners, fertigation, etc.), and growing space requirements. As for revenue, the model estimated potential revenues based on production capacity and market prices. By integrating these factors, the model provided estimates of the impacts of different combinations of strawberry varieties and treatment on fruit production. All three varieties had lower productive performance in the 15/7° C treatment, with Albion and Monterey only producing strawberries in weeks 8 and 9. The 24/16° C treatment showed the best productivity for all varieties, with Monterey achieving best economic results, followed by Cabrillo and lastly, Albion.

Speakers

Amanda Jessica Da Silva

Research Assistant, Michigan State University

Friday September 27, 2024 1:30pm - 1:40pm HST
South Pacific 2

Poster presentation (individual talk), Marketing and Economics

SUBJECT Marketing and Economics

1:35pm HST

VSF 2 - Updates on the Genome Database for Vaccinium (GDV): How GDV supports Vaccinium Research and Breeding

Friday September 27, 2024 1:35pm - 1:45pm HST

South Pacific 3

The Genome Database for Vaccinium (www.vaccinium.org) is a valuable resource for genomics, genetics, and breeding research related to blueberries, cranberries, bilberries, and lingonberries. It provides a wide range of genetic data, including genetic markers, linkage maps, and GWAS/QTL alongside genome data. GDV has the MapViewer tool to dynamically view genetic maps as well as genetic data associated with genomes and powerful search interfaces to query and download genetics data in table formats. For Vaccinium breeders, The Breeding Information Management System (BIMS) is a useful tool for storing, managing, archiving, and analyzing breeding data. Additionally, BIMS can be synchronized with the Field Book App to allow efficient phenotypic data collection and management. This poster will provide an update on new data and tools such as BIMS and MapViewer incorporated in GDV. We will demonstrate how these data and tools can be used for research and breeding activities.

Speakers

Roohollah Abdolshahi

Auburn University

Co-authors

ChunHuai Cheng

Washington State University

Dorrie Main

Washington State University

Jill Bushakra

USDA-ARS

Jing Yu

Washington State University

Jodi Humann

Washington State University

Katheryn Buble

Washington State University

Nahla Bassil

USDA-ARS

Ping Zheng

Washington State University

Sook Jung

Washington State University

Sushan Ru

Auburn University

Taein Lee

Washington State University

Friday September 27, 2024 1:35pm - 1:45pm HST
South Pacific 3

Poster presentation (individual talk), Viticulture and Small Fruits 2

SUBJECT Viticulture

1:40pm HST

MKEC - Economic impact of Winter Injuries on Golf Courses in North America

Friday September 27, 2024 1:40pm - 1:50pm HST

South Pacific 2

Golf courses in the northern regions of the United States and Canada experience occasional damage from winter stresses. This damage can sometimes be very severe, resulting in substantial financial impacts. Winter damage to turfgrass surfaces affects golf course finances in three primary ways: pre-winter maintenance costs, post-winter repair expenses, and revenue losses due to delayed openings. In 2022, a survey was conducted among golf course superintendents in the northern USA. and Canada. This survey collected data on the causes of winter injuries, the extent of damage across the golf course and various management practices employed. Preliminary results have shown that on average the annual costs incurred for preventing winter injuries were between $12,291 and $13,790 and the additional costs resulting from winter injuries ranged from $7,452 to $8,951 per golf course.

Speakers

Chengyan Yue

University of Minnesota-Twin Cities (Minneapolis, MN)

Co-authors

Doug Soldat

University of Wisconsin

Eric Watkins

University of Minnesota-Twin Cities (Minneapolis, MN)

Kevin Frank

Michigan State University

Michelle DaCosta

University of Massachusetts

Paul Koch

University of Wisconsin

Uma Parasuram

University of Minnesota

Friday September 27, 2024 1:40pm - 1:50pm HST
South Pacific 2

Poster presentation (individual talk), Marketing and Economics

SUBJECT Marketing and Economics

1:50pm HST

MKEC - Producing Sweet Potatoes to Manage Farm Income Risk in North Carolina

Friday September 27, 2024 1:50pm - 2:00pm HST

South Pacific 2

The resilience of farmers and farm families are often threatened by the risk associated with farm income. One of the sources of farm income risk is the volatility or variability in crop yields. Climate change or crisis could amplify this risk thereby making farmers, their families and communities less resilient. One of the ways that farmers could manage farm income risk is to diversify their operations by adding crop enterprises. Enterprise diversification works best as an income risk management strategy if the returns from the crop that is being added is negatively correlated with the returns from the other crops. Understanding how the income from some crops or enterprises correlate with those other crops is a vital tool in using diversification as a risk management tool. We assess the suitability of producing sweet potatoes as a way to manage farm income risk through enterprise diversification. We identify major crops that are produced in North Carolina to include cotton, hay, peanuts, soybeans, flue cured tobacco, wheat, squash, strawberries, tomatoes and sweet potatoes. We then derive the annual revenues per acre for each crop as the product of the per acre yield and price per unit for each of the last 15 years. The correlation coefficients between the revenues per acre between sweet potatoes and each of the other crops are estimated. The correlation coefficients between sweet potatoes and the other crops range from -0.002 for squash, and 0.79 for hay. After squash, the next lowest correlation coefficient is between sweet potatoes and snap beans at 0.29 while that with peanuts is 0.47. These results indicate that farm operations in North Carolina that include sweet potatoes and squash could reduce farm revenue risk without substantially reducing the level of revenue.

Speakers

Godfrey Ejimakor

North Carolina A

Friday September 27, 2024 1:50pm - 2:00pm HST
South Pacific 2

Poster presentation (individual talk), Marketing and Economics

SUBJECT Marketing and Economics

2:30pm HST

TCHG - Cultural IPM: Developing a Bilingual Landscaping Basics Booklet

Friday September 27, 2024 2:30pm - 2:40pm HST

South Pacific 4

The USDA NIFA has funds for Extension that support more complex projects than typical programs. Since 2021, a multi-county Extension team has developed a UF/IFAS Bookstore publication titled “Basics of Landscaping in Florida, Conceptos Básicos de Paisajismo en Florida”. This pocket-sized, waterproof guide enables multi-lingual landscape teams to effectively communicate essential landscaping best management practices (BMPs). These BMPs promote long term landscape resilience while reducing reliance on chemical inputs. The environmental horticulture industry in Florida is worth over $10 billion annually, employs over 100,000 people, of which, 33% identify as Hispanic/Latino origin. Most horticulture jobs are focused on landscaping for aesthetics which leads to reactionary pest management focused on quick chemical solutions rather than long term economic, environmental, and social sustainability. In Florida, the use of pesticides and fertilizers requires training and professional licensure, yet chemical control and fertilization represent only a fraction of landscape integrated pest management (IPM). Cultural IPM, on the other hand, offers a key advantage: it allows for effective pest management while significantly reducing pesticide use. However, not all industry professionals require a license to perform their duties, and thus, many lack adequate training on the basics of IPM and BMPs. While quality training programs do exist, they may be cost prohibitive or too advanced for landscape professionals early in their careers or for employees performing basic tasks that fall within cultural IPM foundations. Research shows that people typically add more information and overlook subtractive approaches that may actually improve outcomes (Adams, et. al, 2021). The approach to teaching landscape basics is rooted in age old wisdom, from Occam’s Razor, Einstein’s famous quote, “Everything should be made as simple as possible, but not simpler”, and Lockheed Martin’s “Keep It Simple, Stupid (KISS)” methodologies. Thus, a more basic bilingual training on landscape best practices and IPM was needed and developed as part of the USDA, NIFA Award No. 2021-70006-35560. This booklet uses heuristic techniques designed to effectively communicate fundamental cultural IPM principles to a broader audience in English and Spanish, avoiding intricate and technical facets of horticulture. The team will disseminate booklets to clientele in 2024 and subsequently offer them for sale in the UF/IFAS Bookstore. This presentation will focus on simplifying horticultural science educational technologies, making them accessible, actionable, and agreeable for Floridians working with landscapes. Funding options, considerations, and experiences developing bilingual training materials will also be shared.

Speakers

HANNAH WOOTEN

UF/IFAS

Co-authors

Morgan Pinkerton

UF/IFAS Extension Seminole County

Tatiana Sanchez Jones

UF/IFAS

Tina McIntyre

UF/IFAS

Friday September 27, 2024 2:30pm - 2:40pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

2:40pm HST

TCHG - Learning Outcomes in Floral Design

Friday September 27, 2024 2:40pm - 2:50pm HST

South Pacific 4

Learning objectives are put into place to measure student conceptualization in classroom activities. However, how effective are these learning outcomes in individualized student activities? Our research will explore how well students expressed learning concepts through in-class floral design construction. The target group is the students in HS 275 Floral Design. To study student understanding, we analyzed each week’s learning objectives by evaluating each student's submitted floral design project photograph. This was done through analyzing our review comments and student reflections of their final project. We will discuss the results of our study about applying teaching strategies that promote conceptualization that can potentially be applied broadly in higher education courses.

Speakers

Melinda Knuth

North Carolina State University

Co-authors

Julieta Sherk

NC State University , professor

Julieta Trevino Sherk is a distinguished Professor and professional landscape architect known for her expertise in teaching and community design. At North Carolina State University (NCSU) since 2003, she holds a position in the College of Agriculture and Life Sciences within the Department... Read More →

Friday September 27, 2024 2:40pm - 2:50pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

2:50pm HST

TCHG - Mentor-Mentee Perspectives And Experiences In A Graduate Scientific Communications Course

Friday September 27, 2024 2:50pm - 3:00pm HST

South Pacific 4

TPSS 654 Communications in the Sciences is a required one-credit graduate course in the Tropical Plant & Soil Sciences (TPSS) Department. It covers oral and written communication formats including a CV, thesis/dissertation proposal, scientific journal article, scientific oral presentation, scientific poster, layperson talk, and Scholars Ignite. With 18 students in the class, the instructor found it difficult to provide satisfactory detailed feedback to the students for the seven assignments. The objective was to develop a new course TPSS 711 Special Topics that would enable personalized instruction and mentoring of students on their scientific communications projects. In Spring 2023, five graduate students were registered for TPSS 711—two TPSS students, two NREM students, and one Unclassified student. In Fall 2023, two TPSS graduate students were registered for the course. In Spring 2024, eight graduate students were registered for the course—three TPSS students, three PEPS students, and two HNFAS students. In consultation with the instructor, each student decided on two projects to work on during the semester. The student indicated what specific feedback they were looking for, and the instructor provided individualized assistance with each project. Having this course be TBA (to be announced) regarding meeting dates and times allowed tailoring the course to each student’s schedule. One-to-one meetings enabled more detailed personal instruction that was not possible in the larger TPSS 654 course. Students were more motivated when working on their own projects. Taking TPSS 711 helped me gain insight into how to improve my communication through my writing. I selected two projects that I wanted to improve—my CV and a presentation I was working on—and could meet with the instructor on my own time to ask for guidance on where I could improve. In conclusion, TPSS 711 provided a great opportunity for personalized instruction and sharing. It allowed the instructor to share the many fine points and tips learned over years of studying scientific communications. Being given the option to choose what projects to wanted to work on and what time to meet one-on-one with the instructor made this class very personable. That factor made the quality of TPSS 7111 higher than classes with larger groups since the students were able to spend more time with the instructor.

Speakers

Kent D. Kobayashi

Interim Dept. Chair, TPSS Dept., Univ. of Hawaii at Manoa

Co-authors

Guadalupe Rodriguez

Univ. of Hawaii at Manoa

Friday September 27, 2024 2:50pm - 3:00pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

3:00pm HST

TCHG - Student Engagement and Learning: Evaluating the Effectiveness of Digital Discussion Tools

Friday September 27, 2024 3:00pm - 3:10pm HST

South Pacific 4

Peer-to-peer engagement is an impactful way to enrich student learning and the teaching experience, especially in an asynchronous course. Varied online discussion platforms are more readily available to increase engagement, participation, and student learning. However, more information is needed to evaluate whether these discussion platforms enhance engaged learning. This study compares the use of online discussion platforms Packback and Yellowdig, used in sequential years for HS 205 (Sec. 601): Home Food Production - quantifying students' recorded level of participation, engagement with their classmates, and effort put into student posts. In the spring of 2022, Packback was evaluated as an effective class discussion tool for HS 205 (Sec. 601): Home Food Production. Students used Packback as the course discussion forum tool. Each week, they were given instructor-led lead discussion prompts during scheduled weeks and asked to respond to two of their peers. Packback tracked student participation each week and gave students a “curiosity” score. This curiosity score algorithm assessed the effort put into each student’s post. The Packback discussion group had lower full student participation, peer-to-peer engagement, and curiosity/effort scores. In the first week, most students fully participated. But as weeks progressed, the effort put into discussion posting and engagement significantly declined – as low as 65% participation. Beyond answering the discussion prompt, students did not develop their line of inquiry, and engagement was modest – most weeks, students did not fully participate, and the average curiosity score was 66% (the highest participation was 81 and the lowest 40). In the spring of 2023, Yellowdig was used as a digital tool to help create more vibrant, connected learning communities and give students the agency to discuss course topics that are important to them. Using Yellowdig, evidence showed that students became more active participants in the learning process, often exceeding the minimal participation requirement, and played a critical role in constructing knowledge. Crafted course topics provided course relevance and helped students talk about subjects related to the course, but no longer relied on instructor prompts for their discussions each week. With Yellowdig, students in this course performed above average in the number of student connections, the number of discussion posts, the number of reactions and responses given to discussion posts, the total word count average, and the number of multimedia shared (i.e.pictures, videos, weblinks). Furthermore, several students echoed their value of Yellowdig in their end -of-year evaluations.

Speakers

Remi Ham

Assistant Teaching Professor, North Carolina State University

Remi HamAsst Teaching Professor and Distance Education CoordinatorKilgore Hall NA919-515-5373 raham@ncsu.eduRemi’s body of work ranges from city planning, university planning, and project management. Her recent work has focused on designing edible teaching gardens and developing an environmental curriculum for K-12 schools. Additionally, Remi has focused on reducing food insecurity through com... Read More →

Friday September 27, 2024 3:00pm - 3:10pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

3:10pm HST

TCHG - Training the Next Generation of Leaders to Facilitate Successful and Resilient Urban Food Systems

Friday September 27, 2024 3:10pm - 3:20pm HST

South Pacific 4

Kansas State University formally began working in Urban Food Systems (UFS) with the launch of an UFS specialization in the Horticulture graduate program in 2011. In 2013 it expanded to the KSU-Olathe campus in order to be closer partners and other stakeholders in the Kansas City area. This program provides interdisciplinary training that focuses on sustainable urban food production, local food accessibility, food systems project management, grant writing, public and farmer education, and safe food production in an urban environment. Students gain a foundation in horticultural science while studying how the urban food system impacts social and economic development. There are a number of working urban agriculture professionals that do not have formal education or accreditation in these important topics. Therefore, the MS specialization has a thesis and a professional track (report) option that is intended for working professionals. Based on stakeholder feedback and marketing study performed by KSU, it became clear that there is a strong need for this type of education nationally and for working professionals. An online graduate certificate in urban food systems in January 2022 to address this need. The certificate consist of 6 required credits and 6 elective credits from approved courses in plant and agricultural science, leadership and management, sociology, economics and health. Fall 2023, the professional track MS is available 100% online. Graduates of the program are well prepared to work as director/program managers in not-for-profit organizations, city governments, and extension programs in urban districts, facilitating community gardens, urban farming, farmers’ markets, and farm-to-school programs. Details about the curriculum of the MS specialization and the interdisciplinary graduate certificate will be presented. As urban food systems continue to expand across the US and internationally, it will take a diverse group of professionals to address the complex issues that are relevant to this growing discipline.

Speakers

Eleni Pliakoni

Kansas State University

Co-authors

Cary Rivard

Kansas State University

Jeremy Cowan

Kansas State University

Tricia Jenkins

Kansas State University

Friday September 27, 2024 3:10pm - 3:20pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

3:20pm HST

TCHG - Students’ Knowledge of Landscape Sustainability, Soil Quality and Climate Change Across Experiential Learning Courses i

Friday September 27, 2024 3:20pm - 3:30pm HST

South Pacific 4

Higher education institutions play a crucial role in shaping the future by preparing students to address global sustainability challenges. As we incorporate sustainability principles into teaching and research, faculty members are increasingly adopting an interdisciplinary approach. In particular, colleges of agriculture recognize the urgency of addressing soil degradation, climate change, and land management practices—the very threats that jeopardize global sustainability. However, teaching sustainability is no simple task. Students often grapple with the complexities of land degradation, soil health issues, and the impact of global warming on agriculture. Balancing the need to cover sustainability comprehensively while empowering students to find solutions can be challenging. In response to this challenge, a collaborative effort emerged across five different agriculture college courses. These courses leveraged experiential-learning projects focused on soil quality indicators and climate change mitigation as tools for teaching sustainability concepts. Despite varying levels (ranging from 300 to 400), these courses intentionally shared common components and included research projects, shared readings and reflections, student presentations and a symposium for research competition. The study analyzed over 40 research projects on soil quality and 85 student reflections. The results revealed that students not only acquired a deeper understanding of soil quality variations but also recognized how changes in soil health serve as indicators of land degradation or improvement. Moreover, they appreciated the vital role soil health plays in mitigating climate change. This collaborative approach demonstrates the effectiveness of experiential learning in teaching sustainability. By integrating real-world challenges and fostering interdisciplinary connections, higher education institutions can empower students to become informed stewards of our planet’s future.

Speakers

Iin Handayani

Murray State University

Co-authors

Alyx Shultz

Murray State University

Brian Parr

Murray State University

Friday September 27, 2024 3:20pm - 3:30pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching

3:30pm HST

TCHG - Evaluating In-person and Online Video Teaching Methods to Introduce Landscape Equipment Operation and Safety

Friday September 27, 2024 3:30pm - 3:40pm HST

South Pacific 4

Universities are adapting their teaching methods to progress with changes in technology. With these shifts in teaching, researchers are interested in which methods are best for certain applications. In the agriculture/horticulture realm, there are many studies describing the effects of online vs traditional in-class learning. Most of these studies focus on plant identification and generic species knowledge of plants. This study's purpose is to determine the efficacy of online vs traditional hands-on learning with eight types of landscaping equipment. The study was completed in the fall semester of 2023 at Kansas State University during the Sustainable Landscape Maintenance class. The class was randomly divided into two groups and exposed to one of two teaching methods (hands-on and online videos). Eight commonly used landscape equipment were taught to the students: power hedge trimmer, rotary push mower, de-thatcher, over seeder, ride-on zero-turn mower, sod cutter, string trimmer, and core aerifier). Both the videos and the in-person teaching covered proper operation and safety for each piece of equipment. One group was given in-person, hands- on learning the first week, while the other group watched online videos over the same four pieces of equipment. The following week, the groups switched teaching method delivery and learned the other four pieces of equipment. The students were given a pre- and post-test to assess their comprehension of the equipment. They also participated in a survey after the experiment to show prior experience on the equipment and comfortability after the labs. Results showed that students learn landscape equipment better in person through hands- on learning, rather than relying only on videos. The survey also showed students prefer hands-on demonstrations to become more comfortable operating these pieces of equipment.

Speakers

Levi Dreiling

Kansas State University

Friday September 27, 2024 3:30pm - 3:40pm HST
South Pacific 4

Poster presentation (individual talk), Teaching Methods

3:40pm HST

TCHG - Evaluating Student Understanding of Plant Physiological Processes After Class Presentations

Friday September 27, 2024 3:40pm - 3:50pm HST

South Pacific 4

Concepts of plant water use, photosynthesis, and respiration have historically been challenging for undergraduates in introductory horticulture courses. To increase student understanding of these concepts, we conducted a study in a principles of horticultural science course with two lab sections and a total enrollment of 51 students. After traditional lectures of these plant physiological processes concluded, we used a flipped classroom approach with the learners as teachers to increase student learning. Each lab section was divided into six groups, with 12 groups in total. Groups were assigned one of the three topics and presented their topic to two other groups of students. Five knowledge-based questions on each physiological process, 15 questions total, were included on a pre-test prior to hearing lectures. The same 15 questions were given on a post-test following the lectures, but prior to the student presentations. Those 15 questions were also included on the unit exam following the presentations. No significant differences were found between pre-test and exam scores when evaluated for specific topics students presented. However, an 80% overall score increase from the pre-test to the unit exam was reported. This correlates with student responses to a post-survey in which 80% of the students indicated they understood the other physiological processes better after hearing the group presentations. Our results show that a flipped classroom approach of students teaching students can be effective at increasing student understanding of difficult horticultural concepts.

Speakers

Poster presentation (individual talk), Teaching Methods

SUBJECT Teaching