ASHS 2024 Conference: Full Schedule

9:59am HST

Commercial Horticulture 1 (CHEX 1)

Tuesday September 24, 2024 9:59am - 11:30am HST

A comprehensive analysis of Vidalia Onions transplanting and its impacts - Regimar do Santos
Is Winter Squash a Potential Alternative Cucurbit Vegetable Crop to Combat Whitefly and Whitefly-Transmitted Viruses for Fall Production in Southern Georgia? - Nirmala Acharya
Evaluating Onsite Nitrate and Potassium Sensors - Destany Westlake
Filling the Gaps for Informed Adoption of Carolina Strong Back Grafted Nursery: Transplanting Time and Spacing Optimization - Sukhman Kaur
Substrate Hydro-Physical Properties in Soilless Agriculture: Investigating the Role of Container Geometry on Substrate Air and Water Profiles - Brandan Shur
Kenaf (Hibiscus cannabinus) Compost As An Alternative To Peat - Shawn Steed

Moderator

Nirmala Acharya

University of Georgia

Tuesday September 24, 2024 9:59am - 11:30am HST
South Pacific 2

Oral Sessions, Commercial Horticulture 1

SUBJECT Commercial Hort

10:00am HST

CHEX 1 - A comprehensive analysis of Vidalia Onions transplanting and its impacts

Tuesday September 24, 2024 10:00am - 10:15am HST

South Pacific 2

Onions are a key crop in the United States. In 2023, 138,000 acres were cultivated in the country with onions. Georgia harvested 11,700 acres in 2023, reaching an average production of 129,000 tons. The onion transplanting process is crucial to the crop cycle and is directly linked to the production potential and quality of the bulbs. Every year, thousands of workers are employed to transplant onion seedlings, which results in a wide variation in operational performance and quality of execution between them. These factors are influenced by the experience and conditions in which the workers operate, which can lead to failures in the process, such as double plants, partially transplanted and plants that have fallen to the ground. Furthermore, manual work is slow and requires many workers, increasing the cost of the operation. Therefore, we aimed with this study to assess the time required to manually transplant onions, the quality of manual transplanting, and the impact of inadequate transplanting on crop development. To assess how much time it takes to transplant an acre of onions, and the quality of transplanting, twenty-five people were observed during their work at a commercial field in Glennville-GA. To assess the impact of poor-quality transplanting, an experiment was carried out in four 10ft replications (10x4ft beds) in Reidsville-GA, simulating four situations observed in the commercial field. Treatments were: T1: 25% of the plants in the plot laying on the ground, T2: 25% partially transplanted, T3: 100% properly transplanted, T4: 25% multiple transplanted, T5: 100% laying on the ground. The difference in operational efficiency between workers exceeded ~20 hours per acre. Results indicated that, in average, one person transplanted 1 acre in approximately 30 hours. The fastest person in the crew transplanted in 22 hours, while the slowest took around 40 hours to transplant 1 acre. Poor-quality transplanting of seedlings exceeded up to 11%. The average number of multiple seedlings was 1%, partially transplanted seedlings was 6%, and laying on the ground was 5.5%. Plant development was assessed based on the number of leaves. Properly transplanted seedlings generated a greater number of leaves compared to the other treatments. Higher leaf number was observed in treatment 3 with an average of 7.33 leaves per plant. All the treatments differed from treatment 5, which had an average of 4.6 leaves per plant. Results indicate that good practices on transplanting can increase onion yield.

Speakers

Regimar dos Santos

University of Georgia

Bachelor's degree in agronomic engineering from the Federal University of Mato Grosso do Sul, Brazil at 2021. Master's degree in plant production with an emphasis on computational intelligence in genetic improvement at 2022, with a doctorate in progress at the state university of... Read More →

Co-authors

Luan OIiveira

University of Georgia

Lucas Sales

University of Georgia

Agronomy Engineer graduated from the Federal University of Paraíba. With experience in the management and cultivation of Ornamental Plants, through a year of experience working in Greenhouses in the state of New Hampshire, USA. Experienced in the management and cultivation of vegetables... Read More →

Marcelo Barbosa

University of Georgia

Tuesday September 24, 2024 10:00am - 10:15am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

10:15am HST

CHEX 1 - Is Winter Squash a Potential Alternative Cucurbit Vegetable Crop to Combat Whitefly and Whitefly-Transmitted Viruses for Fall Production in Southern Georgia?

Tuesday September 24, 2024 10:15am - 10:30am HST

South Pacific 2

The predominant cucurbit vegetable crop during fall in Georgia is summer squash with production value of around $94.08 million on 7,757 acres in 2022 while winter squash acreage was insignificant. Whitefly and whitefly-transmitted viruses (WTV) account for 30-50% summer squash yield losses on average and threaten squash production during fall in the region. Cucurbit leaf crumple virus (CuLCrV), Cucurbit yellow stunting disorder virus (CYSDV) and Cucurbit chlorotic yellows virus (CCYV) are the prominent WTV in southern Georgia. We carried out an experiment during fall 2023 in Tifton, Georgia to evaluate tolerance of winter squash varieties for whitefly and WTV and to study their potentiality for fall production in the region. We compared ten commercial hybrid varieties of which two were acorn types (‘Tay Belle’ and ‘Table Ace’), five were butternut types (‘Waltham’, ‘Ceres’, ‘Atlas’, ‘Ultra HP’ and ‘Genesis’), and one each of a hubbard type (‘Golden Hubbard’), a kabocha type (‘Sweet Mama’) and a calabaza type (‘La Estrella’). We collected data on whitefly number, silver leaf disorder, virus incidence and severity, and fruit yield. In addition, we ran quantitative polymerase chain reaction (qPCR) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) on leaf samples to detect and quantify viruses. There were significant differences between winter squash varieties for whitefly feeding preference, silver leaf disorder, virus severity, virus loads and marketable yield. ‘La Estrella’ had the lowest number of whitefly adults per cm2 leaf area followed by all other butternut types (Genesis, Ultra HP, Waltham, Ceres, Atlas), and highest in ‘Tay Belle’, followed by ‘Table Ace’ and ‘Golden Hubbard’. We found significantly severe leaf silvering in ‘Golden Hubbard’ and ‘Sweet Mama’ followed by acorn types. We observed 100% virus incidence in all the varieties, however severity was lowest for ‘Ceres’, ‘Genesis’, ‘La Estrella’, ‘Sweet Mama’, ‘Ultra HP’ and ‘Waltham’. CCYV loads was found highest in ‘Sweet Mama’ and lowest in ‘Genesis’, ‘La Estrella, ‘Ceres’ and ‘Ultra HP’. CYSDV and CuLCrV loads were highest in ‘Table Ace’ and ‘Tay Belle’ and negligible in other varieties. We observed the highest marketable fruit yield in ‘Ceres’ (7,139 count/acre) and ‘Genesis’ (7,109 count/acre). Although ‘La Estrella’ was less infested with whitefly and WTV, it had poor fruit yields. Overall, we found butternut types mainly ‘Ceres’ and ‘Genesis’ as potential alternative cucurbit vegetable crops for fall production in southern Georgia with lower whitefly and WTV infestation resulting in the highest marketable fruit yields.

Speakers

Nirmala Acharya

University of Georgia

Co-authors

David G Riley

University of Georgia

Juan Carlos Diaz Perez

University of Georgia

Manish Kumar

University of Georgia

Sudeep Bag

University of Georgia

Ted McAvoy

University of Georgia

Timothy Coolong

University of Georgia

Tuesday September 24, 2024 10:15am - 10:30am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

10:30am HST

CHEX 1 - Evaluating Onsite Nitrate and Potassium Sensors

Tuesday September 24, 2024 10:30am - 10:45am HST

South Pacific 2

Destany Westlake, Paul Fisher, Josh Tebow, and Ryan Dickson Maintaining nutrient balance in hydroponic systems reduces the need to dump nutrient solution, thereby reducing water and fertilizer cost, and the resulting environmental impact. Laboratory testing to monitor nutrient concentrations is reliable, however it typically requires shipment and days to weeks of processing. The objective was to test the accuracy of handheld and inline ion-selective nitrate and potassium sensors compared with laboratory analysis of these nutrients. The methodology consisted of a factorial design with four reservoirs containing two water qualities and two fertilizer recipes with one nutrient film technique (NFT) system per reservoir. Nitrate and potassium concentration was measured twice per week during a 6-week hydroponic trial with basil, using handheld sensors, inline sensors, and Lachat QuickChem 8500 Series 2 analysis by a commercial horticulture laboratory. Based on the laboratory testing, NO3-N ranged from 142 to 272 mg.L-1 and K ranged from 111 to 271 mg.L-1 during the trial. The average error ± one standard deviation for the handheld sensor minus the laboratory concentration was -26.5 ± 18.8 mg.L-1 and -9.4 ± 13.1 mg.L-1 for N and K, and for the inline sensors was 3.5 ± 27.5 mg.L-1 and -15.2 ± 32.1 mg.L-1 for N and K, respectively. Therefore, we conclude that the handheld and inline sensors provided a useful and rapid estimation of N and K levels, but replicated samples should be taken and these levels should be verified by periodic laboratory analysis. Onsite testing could be an important tool for effective nutrient management to reduce nutrient loss and waste.

Speakers

Destany Westlake

University of Florida

First- year Graduate Environmental Horticulture student.

Co-authors

Josh Tebow

University of Arkansas

Paul Fisher

Floriculture Specialist at the University of FL

Ryan Dickson

University of Arkansas

Tuesday September 24, 2024 10:30am - 10:45am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

10:45am HST

CHEX 1 - Filling the Gaps for Informed Adoption of Carolina Strong Back Grafted Nursery: Transplanting Time and Spacing Optimization

Tuesday September 24, 2024 10:45am - 11:00am HST

South Pacific 2

Grafting is an effective management strategy in watermelon crop against soil borne pathogens. Carolina strongback (SB) rootstock used for grafting, is resistant to both fusarium wilt and root knot nematodes which are devastating soil borne pest of watermelon. In addition, recent studies have shown higher vigour of SB grafted plants than regular nursery plants. However, grafted watermelon nursery is 4-5 times more expensive than regular nursery which leads to reluctance among farmers for adoption of this effective management strategy. Further, recent trials showed that grafted plant bear fruits 7-10 days later than regulate plants leading to farmers losing early profitable watermelon market. To fill these gaps for informed adoption of SB grafted nursery, a field experiment was conducted at Blackville SC with the objective to evaluate the optimum transplanting time and density of SB grafted watermelons nursery to have equivalent fruit yield and harvesting window to that of regular nursery. The experiment comprised of three transplanting times and four transplant densities in a split plot design. We will evaluate the impact of transplanting time and transplanting density on watermelon fruit yield, fruit quality, number of fruits per plant, periodic fruit harvesting yield and plant vigour.

Speakers

Sukhman Kaur

Clemson University

Co-authors

Bhupinder Jatana

Clemson University

Tom Sanders III

Clemson University

Tuesday September 24, 2024 10:45am - 11:00am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

11:00am HST

CHEX 1 - Substrate Hydro-Physical Properties in Soilless Agriculture: Investigating the Role of Container Geometry on Substrate Air and Water Profiles

Tuesday September 24, 2024 11:00am - 11:15am HST

South Pacific 2

The cultivation of specialty crops in soilless growing systems has emerged as a pivotal practice in modern agriculture. The adoption of container-based production, particularly through soilless culture systems, is witnessing a significant uptrend among specialty crop producers. The challenges associated with cultivating plants in containers are extensively documented, particularly in navigating the delicate balance between insufficient and excess water. Shallow containers often result in excessive water, limiting air availability, while the confined volume of containers imposes restrictions on the water supply for optimal plant growth. Air and water capacity (AWC) model was utilized to determine basic physical properties, such as total porosity (TP), air space (AS), and container capacity (CC), for a substrate in specific-sized and shaped containers. AWC models offer a comprehensive tool for estimating hydrophysical properties across multiple substrate/container combinations simultaneously. The existing literature lacks direct reporting on these specific container types, primarily focusing on modeling the air and water profiles of traditional containers that the floriculture industry utilized, leading to a notable gap in data concerning the dynamic interplay between air and water profiles within these containers and their impact on the rooting environment. 19 substrates and 30 commercially used container selections were modeled to understand their air-water profiles. The results underscore the effect of container geometry on substrate air-water profiles, necessitating different management approaches for the same substrate in different containers. Container height stands out as a critical factor, exerting a substantial influence on substrate characteristics and subsequently affecting air and water values.

Speakers

Brandan Shur

North Carolina State University

Co-authors

Brian Jackson

North Carolina State University

William Fonteno

North Carolina State University

Tuesday September 24, 2024 11:00am - 11:15am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

11:15am HST

CHEX 1 - Kenaf (Hibiscus cannabinus) Compost As An Alternative To Peat

Tuesday September 24, 2024 11:15am - 11:30am HST

South Pacific 2

Global growing media demand is projected to increase 400% by 2050. Growers are interested in alternative substrates due to the restrictions placed on peat harvesting, as well as transportation and supply chain issues associated with peat. Kenaf (Hibiscus cannabinus), a tropical fibrous plant that was grown and composted in Florida, was evaluated to determine its potential as a horticultural substrate. Research trials were conducted in South Florida to determine effectiveness of kenaf as an alternative substrate for seed germination and plant establishment when compared to a commercially available compost and commonly used growing media. Seed germination trials consisted of planting arugula (Erica sativa) in seed trays filled with either (1) kenaf compost [KC], (2) commercially available compost [CC], or (3) ProMix HP [PM]. Germination was monitored daily, and mean emergence was determined. To evaluate plant establishment, a container trial was conducted using Lantana (Lantana camara) plants that were originally planted in Metro-Mix and transplanted from 1-gallon to 3-gallon plastic containers filled with either KC, CC or PM. Plant visual quality, percent wilt and volumetric water content(VWC) were evaluated weekly and root biomass was determined when plants were deconstructed at the end of the three-month trial. Results show that there were no treatment differences for percent seed emergence of arugula, with all emergence reaching over 80%. Plant establishment in the first field trial found KC and CC treatments increased VWC when compared to PM. Higher visual quality ratings of plants in KC and CC substrates may be explained by the increase in VWC. Lantana plants transplanted and grown in KC were uniform and grew equally as well as CC and better than PM on 13 of 14 rating dates. These data show there is no difference in arugula seed emergence when planted in CC, PM or KC. Lantana establishment in KC was comparable in CC and better than in PM growing media.

Speakers

Shawn Steed

University of Florida

Co-authors

AC Wilkie

University of Florida

Conner Austin

University of Florida

DG Clarik

University of Florida

E Babaeian

University of Florida

G Landry- Maltais

University of Florida

Liz Felter

University of Florida

mica mcmillan

University of Florida

N Franklin

University of Florida

Tuesday September 24, 2024 11:15am - 11:30am HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 1

SUBJECT Commercial Hort

11:59am HST

Genetics and Germplasm 1 (GG 1)

Tuesday September 24, 2024 11:59am - 1:10pm HST

South Pacific 2

Chromosome Level Assemblies of Phoenix dactylifera L. 'Medjool' and 'Deglet Noor' - Yoko Hiraoka
Development of Haplotype-Phased, Chromosome-scale Genomes for Pomegranate - Alexander Schaller
In Planta Transformation Efficiency Assessment of Different Agrobacterium Strains and Explant Types in Catharanthus rose - Ting Hsuan Huang
Native Southern Red Aroniaberry (Aronia arbutifolia) Response to Chill Hours in Georgia - Leynar Leyton
Enhancing Ornamental Traits through Induced Polyploidy in Hibiscus hamabo: A Cytomolecular Analysis - Hamidou Sakhanokho
Insights into the Genetic Diversity and Population Structure of Wild and Cultivated Spinach - Gehendra Bhattarai
Population Analysis of Wild-type Venezuelan Sabadilla - Luke Czerwinski

Moderator

Hamidou Sakhanokho

USDA-ARS

Tuesday September 24, 2024 11:59am - 1:10pm HST
South Pacific 2

Poster Session, Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:00pm HST

GG 1 - Chromosome Level Assemblies of Phoenix dactylifera L. 'Medjool' and 'Deglet Noor'

Tuesday September 24, 2024 12:00pm - 12:10pm HST

South Pacific 2

Date palm (Phoenix dactylifera L.) is one of the oldest cultivated perennial woody plant species with significant agricultural and economic importance. Date has its center of origin in the Middle East, spreading in ancient times to North Africa and South Asia and later to other hot, arid areas. Dates are a strict dioecious evergreen, obligate outcrossing, and highly heterozygous monocot species that are typically vegetatively propagated. ‘Medjool’ and ‘Deglet Noor’ are the most widely grown date cultivars in the United States and are also important at the global level. Despite their economic values, genomic studies have been hampered due to lack of available assembled genomes. To facilitate future genomic studies, genomes for ‘Medjool’ and ‘Deglet Noor’ were assembled using Dovetail® HiFi and Omni-C® technologies. ‘Medjool’ had a total length of 757 Mb comprising 899 scaffolds (L50 : 7, N50 : 37 Mb) with a BUSCO completeness score of 97.65 %, and ‘Deglet Noor’ had a total length of 772 Mb comprising 1287 scaffolds (L50 : 9, N50 : 33 Mb) with a BUSCO completeness score of 97.65 %.

Speakers

Yoko Hiraoka

University of California Riverside/USDA-ARS

Co-authors

Robert Krueger

United States Department of Agriculture

Tuesday September 24, 2024 12:00pm - 12:10pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:10pm HST

GG 1 - Development of Haplotype-Phased, Chromosome-scale Genomes for Pomegranate

Tuesday September 24, 2024 12:10pm - 12:20pm HST

South Pacific 2

Pomegranates (Punica granatum L.) are a significant fruit crop globally, gaining traction due to their high nutritional value and many uses outside of consumption. Despite increasing interest, genetic resources for pomegranates lag behind other crops. Developing these resources can enhance breeding efficiency and deepen genomic understanding. To address this, we sequenced the genomes of two cultivars: 'Azadi', known for its robust fruit rot resistance, and 'Peppy Le Pom', a dwarf variety with short juvenility. Using the PacBio Revio Platform, we generated HiFi reads with 30x coverage and employed Hi-C for sequencing. Leveraging hifiasm's Hi-C integrated assembly method, we assembled two haplotypes for the genome of each cultivar. For 'Peppy Le Pom', we utilized 10.03 Gb of PacBio HiFi reads and 30 Gb of Hi-C data and constructed two haplotypes with eight chromosome-length scaffolds each, totaling 304.9 Mb and 318.7 Mb, with a BUSCO score of 90.3% and 92.3%, respectively. For 'Azadi', we utilized 10.08 Gb of Pacbio HiFi reads and 30 Gb of Hi-C data and assembled two haplotypes with eight chromosome-length scaffolds, measuring 305.5 Mb and 318.1 Mb, with a BUSCO score of 91.0% and 92.6%, respectively. Chromosome sizes of these pomegranate cultivars range from 27.1 Mb to 62.4 Mb. Notably, these results closely align with the previously published draft genome of the 'Tunisia' cultivar. These phased, chromosome-scale genomes will facilitate further exploration of traits of interest for pomegranate breeding, such as disease resistance, dwarfing, and short juvenility. The genomic resources established here pave the way for accelerated advancements in pomegranate research and breeding.

Speakers

Alexander Schaller

University of Florida

Co-authors

John Chater

University of Florida

Zhanao Deng

University of Florida

Tuesday September 24, 2024 12:10pm - 12:20pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:20pm HST

GG 1 - In Planta Transformation Efficiency Assessment of Different Agrobacterium Strains and Explant Types in Catharanthus rose

Tuesday September 24, 2024 12:20pm - 12:30pm HST

South Pacific 2

Catharanthus roseus (L.) G. Don is a common ornamental crop worldwide due to its high tolerance to drought and heat. The researches on Agrobacterium-mediated transformation of C. roseus are few, and mostly focus on the production of secondary metabolites in roots. Furthermore, the organogenesis from callus to plantlet is frequently unstable which limits the study on entire plant, especially on flowering. The objective of this study is to evaluate the in planta transformation survival rate in different explants and Agrobacterium strains. C. roseus ‘Cora XDR White’ seeds were cultivated in vitro till the cotyledon expanded. Plantlets and cotyledonary nodes were respectively inoculated with two Agrobacterium strains, GV3101 or LBA4404 harboring the binary vector pHEE401E. Explants were co-cultivated in 1/2 MS medium for three days. After washing with sterile water and cefotaxime, the explants were first placed in a medium containing cefotaxime, then were transferred to a same medium that was further added hygromycin. During the elimination and selection, each cotyledonary node turned brown. In the process of subculture, necrotic parts were removed. Result showed that the survival rate of plantlets was 5% in GV3101 treatment. However, LBA4404 ones eventually got brown.

Speakers

Ting Hsuan Huang

Department of Horticultural Science, National Chiayi University

Co-authors

Rong Show Shen

National Chiayi University

Yang Hsin Hsu

National Chiayi University

Yi Chien Lu

National Chiayi University

Tuesday September 24, 2024 12:20pm - 12:30pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:30pm HST

GG 1 - Native Southern Red Aroniaberry (Aronia arbutifolia) Response to Chill Hours in Georgia

Tuesday September 24, 2024 12:30pm - 12:40pm HST

South Pacific 2

Aroniaberry or chokeberry (Aronia sp., Rosaceae) is an attractive deciduous tree-like shrub. Native to eastern and central United States, red aroniaberry (A. arbutifolia) is more predominant in the southern part of the distribution. Bright red fruits, proliferous white flowers in spring, and attractive fall color, make A. arbutifolia a native shrub with ornamental potential. Most of the aroniaberry ornamental varieties available in the market are selections or hybrids of black aroniaberry (A. melanocarpa), they produce black fruit, and do not perform well in sub-tropical climates. We collected triploid and tetraploid A. arbutifolia from five different locations in South Georgia and evaluated their flowering period, fruit production, and response to chill hours in Griffin, GA (Zone 8a, Piedmont region). Plants were exposed to 1000, 800, 600, 400, or 0 chill hours and planted in the field in April of 2023. Flowering timing had a strong correlation with chill hours; plants with chill hours below 600 hrs. presented less flowers and flowering was not uniform.

Speakers

Leynar Leyton

University of Florida

Co-authors

Bodie Pennisi

University of Georgia

Carol Robacker

University of Georgia

Tuesday September 24, 2024 12:30pm - 12:40pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:40pm HST

GG 1 - Enhancing Ornamental Traits through Induced Polyploidy in Hibiscus hamabo: A Cytomolecular Analysis

Tuesday September 24, 2024 12:40pm - 12:50pm HST

South Pacific 2

The Hibiscus genus, encompassing roughly 300 species across 10 sections, presents a diverse and economically significant range of industrial, ornamental, and medicinal properties. Polyploidy, whether occurring spontaneously or induced through external agents, such as chemicals like colchicine and oryzalin, plays a crucial role in plant breeding. It enhances various attributes including flower size, resilience, and metabolite production. Among the species in this genus, Hibiscus hamabo is noted for its salt tolerance and its attractive yellow flowers in summer and golden-yellow or burnt orange leaves in fall. However, H. hamabo typically has small and sparse flowers, which led to our efforts to enhance its ornamental value through induced polyploidy. In our study, we treated germinating seeds of H. hamabo with three concentrations of colchicine (0, 0.125, and 0.25% v/v) for varying durations (6, 12, or 24 hours). The most effective conversion was achieved with seeds treated with 0.25% v/v colchicine for 24 hours. This treatment produced solid polyploids (4n = 184) and mixed-polyploids (2n 4n). The 4n plants exhibited a 2C-DNA content of 8.50 pg, compared to 4.23 pg in the untreated (2n = 92) plants. We evaluated the impact of induced polyploidy on several morphological traits including leaf color, shape, size, trichome density, and plant height. Significant differences were observed between the polyploid plants and the control plants. Additionally, we explored the cytomolecular analysis of induced polyploidy, particularly focusing on the distribution and organization of rDNA. In 2n plants, one locus of 5S and four loci of 35S rDNA (two major and two minor) were identified. The 5S site is pericentromeric, while one of the major 35S sites is sub-terminal, and the others are at terminal locations. In 4n plants, the number of 5S and 35S sites was exactly duplicated, confirming the polyploidization at the genetic level. Our results proved that colchicine can be used to induce polyploidy in germinating H. hamabo seeds, paving the way for the improvement of this species through this method.

Speakers

Hamidou Sakhanokho

USDA-ARS

Co-authors

Barbara J Smithe

USDA

Nurul Islam-Faridi

USDA

Tuesday September 24, 2024 12:40pm - 12:50pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

12:50pm HST

GG 1 - Insights into the Genetic Diversity and Population Structure of Wild and Cultivated Spinach

Tuesday September 24, 2024 12:50pm - 1:00pm HST

South Pacific 2

The wealth of genetic and phenotypic diversity in plant species serves as the primary source of novel traits in plant breeding and crop improvement efforts. Spinach (Spinacia oleracea) has a long cultivation history across diverse environments and geographic regions, which has resulted in adaptation to diverse conditions. This adaptation has been influenced further by human preferences for distinct leaf shapes, tastes, flavors, and nutrition, constituting a rich reserve of genetic and phenotypic diversity within Spinacia germplasm. Moreover, wild species (S. tetrandra and S. turkestanica) offer valuable resources, particularly for traits of commercial significance, such as resistance to prevalent pathogens and pests. Therefore, understanding the genetic variations that underlie phenotypic traits is crucial to enable effective gene introgression and the development of novel spinach varieties. We recently investigated the genetic diversity and population structure of a panel of over 500 cultivated and wild germplasm obtained from the Centre for Genetic Resources, the Netherlands (CGN) at Wageningen University and Research (WUR). This panel, complemented with material from other sources, comprised 49 S. tetrandra and 86 S. turkestanica accessions. Our findings revealed the presence of significant genetic diversity within these panels of accessions, which were categorized into multiple distinct population groups. We evaluate this Spinacia panel for several horticulturally important traits to identify SNP markers and candidate gene regions associated with commercially important traits. Our objectives are to share novel insights into the genetic diversity of spinach and provide valuable molecular markers for improving cultivated spinach production.

Speakers

Gehendra Bhattarai

University of Arkansas

Co-authors

Ainong Shi

Associate Professor, University of Arkasnas

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

Chris Kik

Centre for Genetic Resources, the Netherlands (CGN), Wageningen University and Research

Lindsey du Toit

Mount Vernon Northwestern Washington Research and Extension Center, Washington State University

Rob van Treuren

Centre for Genetic Resources, the Netherlands (CGN), Wageningen University and Research

Sanjaya Gyawali

Sakata Seed America Inc.

Tuesday September 24, 2024 12:50pm - 1:00pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

1:00pm HST

GG 1 - Population Analysis of Wild-type Venezuelan Sabadilla

Tuesday September 24, 2024 1:00pm - 1:10pm HST

South Pacific 2

Schoenocaulon officinale, also known by the common name of sabadilla, is a species of plant belonging to the family Liliaceae. It is thought to be endemic to Mexico; at some point in history, it was spread throughout other parts of South America. Sabadilla is a geophytic perennial bulb plant that is not frost tolerant. Due to the environmental factors where sabadilla grows, it is also hypothesized to be a heliophyte. It is estimated to live, while continuously flowering, for up to 8 years. Sabadilla will normally reach its mature stage at around year 2-3. The seeds of sabadilla contain two insecticidally active chemical compounds known as veratridine and cevadine. The normal compositional range that these compounds make up in the seeds is anywhere from 0.5-5%. The mode of action is similar to that of pyrethrins; these compounds will attach to sodium channels on the insects and cause continuous overactivation until the insect is knocked. It is not yet known which specific sodium channel these compounds act on. Sabadilla has been used by people for thousands of years for its insecticidal properties and alleged homeopathic benefits. However, sabadilla is a relatively untouched and unstudied plant. Due to this, almost no biological, physiological, or genetic work has been done on the plant. The purpose of this research was to delve deeper into population differences of plants that were collected from different environments in Venezuela. In 2019, seeds were collected from 7 distinct geographic locations in Venezuela. They were collected from two different sites (The Ávila National Park

Speakers

Lukas Czerwinski

MGK

Tuesday September 24, 2024 1:00pm - 1:10pm HST
South Pacific 2

Poster presentation (individual talk), Genetics and Germplasm 1

SUBJECT Genetics and Germplasm

1:29pm HST

Ornamental Plant Breeding (OPB)

Tuesday September 24, 2024 1:29pm - 2:00pm HST

South Pacific 2

Create Novel Interspecific Hybrids between Tuberous Begonia and B. semperflorens by Using Embryo Rescue Technique - Yen Ming Chen
Breeding the Unbreedable: Innovating the Generation of Sterile Triploid Lantana through Open-Pollinated Interploidy Crosses - Brooks Parrish
Tetraploid plants of Samanea (Albizia) saman on diploid roots grew similarly to mixoploid and diploid plants on diploid roots while tetraploid plants on tetraploid roots were inferior to triploid plants on triploid roots - Alberto Ricordi

Moderator

Brooks Parrish

University of Florida

Tuesday September 24, 2024 1:29pm - 2:00pm HST
South Pacific 2

Poster Session, Ornamental Plant Breeding

SUBJECT Ornamental Plant Breeding

1:30pm HST

OPB - Create Novel Interspecific Hybrids between Tuberous Begonia and B. semperflorens by Using Embryo Rescue Technique

Tuesday September 24, 2024 1:30pm - 1:40pm HST

South Pacific 2

Genus Begonia is prominent ornamental bedding and potted flower crop, encompassing types such as Rieger Begonia (Begonia × hiemalis), Tuberous Begonia (Begonia tuberhybrida), and B. semperflorens, which are extensively cultivated. Building upon the breeding methodology of Rieger Begonia, this study endeavors to utilize Tuberous Begonia as the maternal parent and integrate the attributes of B. semperflorens to develop innovative interspecific hybrid varieties. Interspecific hybridization was accomplished by using Tuberous Begonia 'Fortunate' as the female parent and B. semperflorens as pollen donor through embryo rescue techniques, resulting in successful interspecific offsprings. Flow cytometry analysis revealed the expected DNA content combination in the hybrids. Furthermore, Random Amplified Polymorphic DNA (RAPD) analysis confirmed the authenticity of the interspecific hybrids by exhibiting specific bands of both parents. The plant type, basal branching habit, and leaf shape of the hybrids resembled those of the male parent, B. semperflorens, while the double flower characteristic inherited from the female parent. Additionally, the hybrids exhibited year-round flowering without requiring photoperiod treatment and showed no apparent dormancy, rendering them suitable for continuous production. These hybrids are also exhibiting robust branching habits and possess distinctive plant traits compared to commercially available Rieger Begonias. They are particularly suited for cultivation in hot and humid regions. Evaluation of production and growth advantages indicated their capability for year-round supply and commercial production. Applications for Plant Variety Rights have been submitted for these hybrids in Taiwan.

Speakers

YEN MING CHEN

National Chung Hsing University

Tuesday September 24, 2024 1:30pm - 1:40pm HST
South Pacific 2

Poster presentation (individual talk), Ornamental Plant Breeding

SUBJECT Ornamental Plant Breeding

1:40pm HST

OPB - Breeding the Unbreedable: Innovating the Generation of Sterile Triploid Lantana through Open-Pollinated Interploidy Cros

Tuesday September 24, 2024 1:40pm - 1:50pm HST

South Pacific 2

This study presents a groundbreaking field breeding strategy for Lantana camara, a plant celebrated for its ornamental value yet criticized for its invasive tendencies. Traditional hand pollination techniques for lantana are labor-intensive, as each flower produces only one seed, making the generation of significant populations time-consuming. Although open pollination represents an alternative for seed production, the reliability of generating sterile triploids through interploidy crosses has been questionable. Addressing these challenges, this research innovatively employs open-pollinated breeding between diploid and tetraploid populations to efficiently produce sterile triploid cultivars. The method leverages male-sterile tetraploids for open pollination with female-sterile, male-fertile diploids, yielding 544 triploid seeds within five weeks and proving the effectiveness of interploidy hybridization. Moreover, diploid populations in an all-by-all cross setup produced over 2,000 seeds in the same period, eliminating the need for hand pollinations. Nonetheless, the development of tetraploid breeding lines encountered obstacles due to insufficient pollen transfer, likely resulting from low pollen production, although selfing within hybrid lines remained feasible in an open-pollinated field setting. These findings significantly advance the fields of ornamental breeding and invasive species management, providing fresh perspectives on the cultivation and control of Lantana camara. Demonstrating the capability to rapidly produce large volumes of sterile triploid lines with minimal labor, this study lays the groundwork for the broader availability of non-invasive Lantana camara alternatives in the future.

Speakers

Brooks Parrish

University of Florida

Co-authors

Zhanao Deng

University of Florida

Tuesday September 24, 2024 1:40pm - 1:50pm HST
South Pacific 2

Poster presentation (individual talk), Ornamental Plant Breeding

SUBJECT Ornamental Plant Breeding

1:50pm HST

OPB - Tetraploid plants of Samanea (Albizia) saman on diploid roots grew similarly to mixoploid and diploid plants on diploid

Tuesday September 24, 2024 1:50pm - 2:00pm HST

South Pacific 2

Many legume trees are notorious for their prolific production of seedpods, which are usually large and in many cases stink when cracked open. Such pods affect both the beauty and sensory perception of the tree, and may be slippery and hazardous on walking surfaces. For example, Samanea (Albizia) saman, which has naturalized in many tropical and subtropical places and is commonly known in Hawaii as monkey pod tree, is a favorite landscape tree in Hawaii for its large canopy, especially in parking lots and parks. Unfortunately, this species produces a large amount of sticky pods that stick to shoes and tires, and can create an objectionable mess, a high volume of green waste and high maintenance of parking lots. The seedpods are heavy to rake and can cause damage to lawn mower blades. Seedless cultivars would have no potential to become invasive and their maintenance cost would be much lower. Seed-bearing ornamental plants can be converted to triploid, non-seed-bearing forms, and thereby eliminate their invasiveness and reduce their maintenance. Triploid plants rarely produce functional gametes, because they do not undergo normal meiosis, and the resulting sterility accounts for the economically valuable seedlessness of triploid bananas, limes, and seedless watermelons. Sterile nursery plants can be used for landscaping virtually without any possibility to become invasive. In a field trial at the University of Hawaii Waimanalo Research Station, it was observed that tetraploid plants of Samanea (Albizia) saman on diploid roots grew similarly to mixoploid and diploid plants on diploid roots. These tetraploid plants were developed by treating the apical meristem of diploid seedlings with 0.1% colchicine for 48h. Therefore, the root system remained diploid, while the above ground portion of the plants were tetraploid. However, tetraploid plants on tetraploid roots, grown from seeds harvested from tetraploid induced plants, were inferior to triploid plants on triploid roots. Triploid plants were almost double in size (67% taller, had 109% wider canopy, and 90% larger DAB, n=8). This is the first time that this phenomenon has been documented in Samanea spp.

Speakers

Alberto Ricordi

University of Hawaii at Manoa

Co-authors

Kenneth Leonhardt

University of Hawaii at Manoa

Tuesday September 24, 2024 1:50pm - 2:00pm HST
South Pacific 2

Poster presentation (individual talk), Ornamental Plant Breeding

SUBJECT Ornamental Plant Breeding

2:14pm HST

Postharvest 1 (PH 1)

Tuesday September 24, 2024 2:14pm - 4:00pm HST

South Pacific 2

Ethylene Degreening: A Technique to Enhance Peel Color of Georgia-Grown Satsuma (Citrus reticulata) Citrus Fruit - Taiwo Owolanke
Postharvest Storage Temperatures to Promote Anthocyanin Accumulation and Antioxidant Activity in Blood Orange cv. Moro - Fariborz Habibi
Preserving Flavor in Grapefruit Juice: Continuous Flow High-Pressure Homogenization Versus Conventional Treatment - Jayashan Adhikari
Effects of Alternative Atmosphere Storage on the Postharvest Quality of Georgia-grown Blackberries - Ramsey Corn
Examining the Effect of Storage Temperatures on Chilling Injury Incidence of Georgia-Grown Peaches - Orestis Giannopoulos
Postharvest melatonin application maintains quality of jackfruit bulbs by alleviating enzymatic browning and oxidative stress under low temperature storage - Jashanpreet Kaur
Catalysis of 1-Methylcyclopropene Degradation By Non-Target Materials: Metals and Metal Salts - Ozge Horzum

Moderator

Taiwo Owolanke

Graduate Research Assistant, University of Georgia

Tuesday September 24, 2024 2:14pm - 4:00pm HST
South Pacific 2

Oral Sessions, Postharvest 1

SUBJECT Postharvest

2:15pm HST

PH 1 - Ethylene Degreening: A Technique to Enhance Peel Color of Georgia-Grown Satsuma (Citrus reticulata) Citrus Fruit

Tuesday September 24, 2024 2:15pm - 2:30pm HST

South Pacific 2

In recent years, the production of Satsuma oranges (Citrus reticulata) has significantly increased in the state of Georgia. Satsumas are known to develop a deep orange peel color naturally when the temperature drops below 12°C at night. However, due to the subtropical climate of South Georgia, the fruit often fails to turn orange naturally even after attaining physiological maturity standards. Consumers tend to choose fruits based on appearance, with brightly colored oranges being more likely to attract buyers. Degreening is a postharvest technique that utilizes gaseous ethylene (C2H4) to accelerate and promote the development of orange/yellow color pigments in fresh-market citrus fruit. The study was conducted using four Satsuma cultivars ('Brown Select', 'Owari', 'Miho', and 'Xie Shan') harvested at physiological maturity yet with green peel coloration. The fruit samples were subjected to a degreening treatment which involved exposure to a continuous flow of

Speakers

Taiwo Owolanke

Graduate Research Assistant, University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Anthony Bateman

University of Georgia

Jake Price

University of Georgia, Extension

Orestis Giannopoulos

University of Georgia

Ramsey Corn

University of Georgia

Tuesday September 24, 2024 2:15pm - 2:30pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

2:30pm HST

PH 1 - Postharvest Storage Temperatures to Promote Anthocyanin Accumulation and Antioxidant Activity in Blood Orange cv. Moro

Tuesday September 24, 2024 2:30pm - 2:45pm HST

South Pacific 2

Blood oranges (Citrus sinensis L. Osbeck) fruit contain valuable compounds for human health, including anthocyanins, flavonoids, polyphenols, hydroxycinnamic acids, and ascorbic acid. Anthocyanin is considered an important internal quality index of blood oranges due to its red color and antioxidant activity. Blood orange pigmentation under similar growing conditions depends on some factors including cultivar, cultural practices, soil characteristics, climate conditions, maturity, and harvest maturity. Blood orange fruit require cold temperatures between 8 °C to 15 °C during the last ripening stages to develop high levels of anthocyanin in their flesh. However, commercial production of blood oranges in subtropical or tropical regions is limited due to very low or lack of cold temperatures to enhance anthocyanin concentration in fruit. We evaluated the effect of different storage temperatures (10, 15, and 20 °C) on anthocyanin enhancement and the antioxidant activity of ‘Moro’ blood orange for 42 days. Fruit were harvested from a commercial citrus orchard in south Georgia and transported to the postharvest lab in Gainesville, Florida. Fruit were checked for absence of defects andr rind injuries, sanitized with 100 ppm sodium hypochlorite solution, and superficial water removed from the fruit surface. The fruit were then divided into sets of four replicates of 10 fruit per treatment and placed in mesh bags for storage at 10, 15, or 20 °C with 90 % relative humidity. Anthocyanin accumulation and antioxidant activity in the flesh were evaluated every 14 days for 42 days. There were significant differences among the applied storage temperatures for anthocyanin content and antioxidant activity. The highest anthocyanin concentration and antioxidant activity were observed at 10 °C, while the lowest anthocyanin level was at 20 °C for all sampling times. The efficiency of these temperatures in enhancing flesh anthocyanin and antioxidant activity was in the following order: 10 °C > 15 °C > 20 °C at all sampling times. Overall, it can be concluded that cold storage can be used as a simple technology for enhancing bioactive compounds and antioxidant activity in blood oranges that are poorly pigmented at harvest in subtropical or tropical climates like Florida.

Speakers

Fariborz Habibi

University of Florida

Co-authors

Ali Sarkhosh

University of Florida

Jeffrey Brecht

University of Florida

Tuesday September 24, 2024 2:30pm - 2:45pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

2:45pm HST

PH 1 - Preserving Flavor in Grapefruit Juice: Continuous Flow High-Pressure Homogenization Versus Conventional Treatment

Tuesday September 24, 2024 2:45pm - 3:00pm HST

South Pacific 2

Grapefruit is known for its citrus aroma and tangy flavor. Processors use post-harvest preservation methods for juice production to maintain quality during storage for market distribution. These processes aim to preserve quality and safety while reducing unwanted compounds such as furanocoumarins. However, traditional methods like thermal pasteurization alter sensory quality and nutrient contents. With consumers demanding fresh-like taste without safety issues, researchers have aimed to develop new processing technologies. Here, we tested continuous flow high-pressure homogenization (CFHPH) for grapefruit juice processing. This method may extend shelf-life while maintaining fresh-like flavor. In this study, CFHPH was applied at various pressure levels (200, 250, 300 MPa), inlet temperatures (4 or 22 °C), and a flow rate of 1.125 L/min, and compared with conventional high-temperature short time (HTST) processing for preserving flavor compounds in Ruby Red grapefruit juice during storage at 4 °C for 45 days. Gas chromatography–mass spectrometry analysis identified key volatile compounds such as limonene, myrcene, α-pinene, β-pinene, and linalool. CFHPH preserved flavor compounds better than HTST, while HTST treatments led to flavor loss and off-notes. CFHPH maintained major volatiles like limonene, suggesting its potential as a consumer-preferred preservation method. This research underscores the significance of innovative techniques for maintaining grapefruit juice sensory quality, which is essential for customer satisfaction and market success.

Speakers

Jayashan Adhikari

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Koushik Adhikari

University of Georgia

Rakesh Singh

University of Georgia

Tuesday September 24, 2024 2:45pm - 3:00pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

3:00pm HST

PH 1 - Effects of Alternative Atmosphere Storage on the Postharvest Quality of Georgia-grown Blackberries

Tuesday September 24, 2024 3:00pm - 3:15pm HST

South Pacific 2

Blackberries have several susceptibilities that contribute to the fruit’s high perishability resulting in a short shelf-life. The industry-standard technique for maintaining the postharvest quality is to store berries in a room with low temperature and high relative humidity to slow senescence. Despite the use of cold storage, the shelf-life of fresh-market blackberries can be short, limiting their marketing potential. The application of innovative technologies such as controlled atmospheres (CA), or the addition of gaseous ozone (O3) to the cold storage rooms could aid in maintaining the postharvest quality. During the 2023 blackberry season, three harvests were conducted paired with a sensory survey one day after. Four blackberry cultivars (Caddo, Ouachita, Ponca, Osage) were hand-picked, field-packed, and hand-sorted before being placed into cold storage. The storage conditions included a control of cold storage (1 °C, 95% RH), cold storage with additional controlled atmosphere (10% CO2 10% O2), and cold storage with gaseous ozone (0.5 ppm). The blackberries were kept under the above storage conditions for up to 21 days, with quality assessments occurring every seventh day. Quality assessments included sensory attributes of visual quality, weight loss, color, firmness, respiration rates, red drupelet reversion (RDR) presence, anthocyanin content, titratable acidity, and total soluble solids. Significant differences between treatments were recorded in fruit firmness of Caddo and Ouachita berries after seven days of storage. The CA and ozone treatments resulted in higher firmness of Caddo berries compared to the control. The CA and ozone treatments resulting in lower firmness of Ouachita berries compared to the control. RDR was separated by presence of RDR with the parameters none, low, and high. In each harvest, Ouachita had the highest presence of RDR after harvest compared to the other cultivars. Caddo exhibited low to no RDR in each harvest initially and after storage. Caddo was favored by panelists in the sensory survey related to the overall flavor and overall appearance. The experiment will be repeated during the 2024 blackberry season to evaluate the above cultivars’ aroma volatile compound levels using a GC/MS system.

Speakers

Ramsey Corn

University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Orestis Giannopoulos

University of Georgia

Zilfina Rubio

University of Georgia

Tuesday September 24, 2024 3:00pm - 3:15pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

3:15pm HST

PH 1 - Examining the Effect of Storage Temperatures on Chilling Injury Incidence of Georgia-Grown Peaches

Tuesday September 24, 2024 3:15pm - 3:30pm HST

South Pacific 2

Peaches are climacteric fruit that can continue ripening after harvest. When stored at elevated temperatures, peaches exhibit higher respiration rates and increased ethylene production, which makes low-temperature storage key for quality preservation. Cold storage slows down metabolic activities responsible for senescence. However, temperatures between 36 and 46°F (2.2-7.7°C) might induce a disorder commonly known as chilling injury, hence, this range has been named by many scientists as the “killing zone”. The disorder is detrimental to peach quality as it affects the flesh texture, appearance, and fruit juiciness overall. Depending on the severity, peaches might not show external symptoms of the disorder which usually appears after transfer to ambient conditions. Factors such as varietal differences, storage durations, and growing conditions may influence the severity of chilling injury symptoms. Very little research has been done in the Southeast regarding chilling injury incidence, while many of the newer cultivars have never been investigated. This project aimed to investigate the appearance of chilling injury symptoms in important peach cultivars grown in the Southeastern United States. Peaches were stored at five different temperatures of 33, 36, 41, 46, and 50°F (0.5, 2.2, 5, 7.7, and 10°C) and 95% relative humidity for up to four weeks. Quality evaluations occurred on days 0, 7, 14, 21, and 28 after harvest, which were followed by three days of ambient storage to allow for the development of chilling injury. Quality measurements included weight loss, decay incidence, total soluble solids, titratable acidity, firmness, as well as visual appearance. Results show that 33°F storage temperatures had lower respiration. Higher storage temperatures of 41, 46, and 50°F resulted in increased weight loss and lower firmness readings. Peaches stored at 33 and 36°F were juicier until the 21st day of storage. All tested temperatures were tolerated for a storage period of 7 days, with no visible symptoms. On the other hand, storage durations longer than 14 days at temperatures of 36, 41, and 46°F showed the highest chilling injury incidence. More research is currently underway in order to create a map of chilling injury tolerance across different cultivars that are important for the Southeastern region.

Speakers

Orestis Giannopoulos

University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Dario Chavez

University of Georgia

Ramsey Corn

University of Georgia

Tuesday September 24, 2024 3:15pm - 3:30pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

3:30pm HST

PH 1 - Postharvest melatonin application maintains quality of jackfruit bulbs by alleviating enzymatic browning and oxidative stress under low temperature storage

Tuesday September 24, 2024 3:30pm - 3:45pm HST

South Pacific 2

Jackfruit bulbs are susceptible to postharvest browning which is a major factor limiting shelf life and marketability. In this investigation, the impact of postharvest melatonin (MLT) application on enzymatic browning and antioxidant metabolism in jackfruit bulbs was evaluated. Jackfruit bulbs were dipped in different concentrations of MLT (0, 0.05, 0.1 and 0.2 mmol L-1) prior to cold storage at 4 ± 1 °C temperature and 85-90% relative humidity over the duration of 20d. MLT application considerably delayed the process of senescence as demonstrated by a reduction in browning index and softening of bulbs with 0.1 and 0.2 mmol L-1 MLT application, respectively. At the end of the storage period, 0.2 mmol L-1 MLT treatment significantly maintained higher ascorbic acid (46.9 %), total phenolics (22.3%) and total carotenoids (26.3%) compared to control. Whilst 0.1 mmol L-1 MLT application curtailed fruit weight loss (46.0%) and improved total flavonoid content (16.7 %) and DPPH radical scavenging activity (12.5%) as compared to the control. The levels of polyphenol oxidase and guaiacol peroxidase were significantly lower in 0.1 mmol L-1 and 0.2 mmol L-1 MLT treated bulbs, respectively. The activity of antioxidant enzymes including catalase, superoxide dismutase, and ascorbate peroxidase was improved with the application of 0.2 mmol L-1 MLT. In addition, all MLT treatments effectively reduced malondialdehyde, lipoxygenase and hydrogen peroxide radicals. These findings suggest that dip treatment of MLT (0.1 and 0.2 mmol L-1) effectively lessen flesh browning along with maintenance of antioxidant potential and postharvest quality of jackfruit bulbs.

Speakers

Jashanpreet Kaur

PhD Scholar, Edith Cowan University

Co-authors

Andrew Woodward

Edith Cowan University, Joondalup, Western Australia, Australia

Eben Afrifa-Yamoah

Edith Cowan University, Joondalup, Western Australia, Australia

Hafiz Muhammad Shoaib Shah

Edith Cowan University, Joondalup, Western Australia, Australia

Muhammad Sohail Mazhar

Department of Industry, Tourism and Trade Northern Territory

Zora Singh

Edith Cowan University

Tuesday September 24, 2024 3:30pm - 3:45pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

3:45pm HST

PH 1 - Catalysis of 1-Methylcyclopropene Degradation By Non-Target Materials: Metals and Metal Salts

Tuesday September 24, 2024 3:45pm - 4:00pm HST

South Pacific 2

1-Methylcyclopropene is a cyclic olefin that inhibits ethylene action and is released as a gas from a formulated cyclodextrin. Different concentrations of 1-MCP are used globally in the fruit industry to enhance the preservation of quality attributes. The concentrations applied cannot be considered stable due to losses to target and non-target sites within the storage or treatment room environment. Copper is used in cooling systems because it transfers heat more efficiently than many other materials, but it is also used as a catalyst for chemical modification. So, we investigated the absorption or degradation of 1-MCP by various metals, including copper. These forms included metal bars (hot and cold-rolled steel, aluminum, galvanized metal, silver, gold, stainless steel, and brass), copper pipes (polished, oxidized, and with patina) and copper salts [covellite (CuS, copper II sulfide); eriochalcite (CuCl22H2O, copper II chloride); chalcopyrite (CuFeS2, copper iron sulfide); cupric carbonate (CuCO3, copper II carbonate); chalcocite (Cu2S, copper I sulfide), cuprite (Cu2O, copper I oxide); chalcanthite (CuSO45H2O, copper sulfate); tenorite (CuO, copper II oxide), and cupric acetate (Cu(CH3CO2)2, copper II acetate)], which possessed copper atoms at different levels of oxidation. The metal pieces had a surface area of 435 cm2, and the powders weighed 1 g. We put the materials in 480-mL glass jars and added 50 μL L−1 of 1-MCP gas to the headspace. Gas concentrations were measured at 0, 2, 4, 6, and 24 h in both humid and dry conditions at room temperature. The loss of 1-MCP was more pronounced in humid condition than in dry condition except when exposed to cupric carbonate. While covellite, eriochalcite, and chalcopyrite caused a 1-MCP loss of over 90% within 24 h in both conditions, stainless steel, aluminum, galvanized iron mesh, silver and galvanized iron yielded a 1-MCP loss below 10%. On the other hand, the impact of copper pipes on reducing 1-MCP is evident, and the reduction of 1-MCP also increases as the oxidation level of the copper increases. Based on mass spectral analysis of the headspace in the treatment chambers, the decrease of 1-MCP appears to occur by adsorption by the materials, polymerization, and disintegration into break-down products. The implications for 1-MCP reductions in commercial treatment rooms will be discussed.

Speakers

Ozge Horzum

Ankara University

Co-authors

Nobuko Sugimoto

Michigan State University

Philip Engelgau

Michigan State University

Randolph Beaudry

Michigan State University

Dr. Randolph Beaudry, Professor, MSU Department of Horticulture (MSc, PhD, University of Georgia). His appointment is 50% MSU Extension and 50% AgBioResearch. His research program includes both regional and international projects and focuses on the physiology of plant responses to... Read More →

Tuesday September 24, 2024 3:45pm - 4:00pm HST
South Pacific 2

Oral presentation (Individual talk), Postharvest 1

SUBJECT Postharvest

4:59pm HST

Technology (TECH) - Poster

Tuesday September 24, 2024 4:59pm - 6:00pm HST

South Pacific 2

Growth-promoting Bacteria in Improving the Biophysical Parameters of Cherry Tomatoes (Solanum lycopersicum L.) - Henrique Oliveira
Promoting Controlled Environment Agriculture Activities At Campus-Wide Events - Kent Kobayashi
Rapid Detection of Herbicide-Resistant Weeds Utilizing Novel Full-Spectrum Imaging and a Hyperparameter-Tuned Convolutional Neural Network (CNN) - Pauline Victoria Estrada
Puʻuhonua Kauluwehi: Maui Wildfire Rapid Response Strategies for Agroecosystem Resilience and Community Well-Being - Nicolette van der Lee
Enhancing Hot Pepper Quality and Yield through Smart Irrigation Strategies - Harmandeep Sharma
Spraying Drone Efficiency: A Comparative Study of Application Rate and Surfactant Addition - Lucas Sales

Moderator

Nicolette van der Lee

Program Manager, University of Hawaii Maui College

Tuesday September 24, 2024 4:59pm - 6:00pm HST
South Pacific 2

Poster Session, Technology Applications in Horticulture 1

SUBJECT Technology

5:00pm HST

TECH - Growth-promoting Bacteria in Improving the Biophysical Parameters of Cherry Tomatoes (Solanum lycopersicum L.)

Tuesday September 24, 2024 5:00pm - 5:10pm HST

South Pacific 2

As a strategy, the use of plant growth-promoting bacteria (PGPB) in agriculture has stood out because they interact symbiotically with plants, promoting their growth directly or indirectly. The objective of this study was to evaluate the effects of the effects of inoculation with Bacillus subtilis ATCC 23858 and Burkholderia seminalis TC3.4.2R3 on the biopshycal characteristics of the plants, technological attributes of the fruits, and productivity of common cherry tomatoes . The experiment was arranged in a randomized block design with three treatments: i) inoculation with Bacillus subtilis ATCC 23858; ii) inoculation with Burkholderia seminalis TC3.4.2R3; and iii) non-inoculation, with eight replications. The data were subjected to analysis of variance (ANOVA) using the F-test followed by the Tukey test (P

Speakers

Henrique Oliveira

Goiano Federal Institute

Co-authors

Jhon Lennon Bezerra da Silva

Goiano Federal Institute

Marcio Mesquita

Federal University of Goiás

Marcos Vinicius da Silva

Federal Rural University of Pernambuco

Priscila Jane Romano G Selari

Goiano Federal Institute

Thiago Dias Silva

Goiano Federal Institute

Wesley de Melo Rangel

Goiano Federal Institute

Tuesday September 24, 2024 5:00pm - 5:10pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

5:10pm HST

TECH - Promoting Controlled Environment Agriculture Activities At Campus-Wide Events

Tuesday September 24, 2024 5:10pm - 5:20pm HST

South Pacific 2

How can we help students, the public, and stakeholders become familiar and engaged with controlled environment agriculture (CEA) and its benefits? Besides offering undergraduate courses such as TPSS 300 Tropical Production Systems and TPSS 491 Experimental Topics "Controlled Environment Agriculture" we sought other ways to accomplish this. The objective is to describe how we use displays about our CEA lab at campus-wide events to help inform audiences about CEA and its technology. Various events at the University of Hawaii at Manoa (UHM) enable colleges, departments, units, and individual laboratories the opportunity to showcase their programs, curricula, and research. At these campus-wide events, we set up table displays that explain CEA and highlight our CEA research. Our displays exhibit various aspects of the technology used in CEA such as LED (light-emitting diodes) lights, hydroponics, and greenhouse materials. We display high tech acrylic greenhouse coverings and walls, smart glass, photoselective shadecloths, and light spectrum control plastic films to show recent developments in greenhouse coverings. Hydroponic principles are explained through the use of micro-hydroponics, dwarf vegetables grown under LED lights, and hydroponic kits. A display using simulated Martian soils and LEGO® figures shows a Martian landscape with a plastic dome greenhouse with plastic vegetables growing inside. The audience gets to experience a hands-on working miniature grow tent, a replica of actual grow tents, to demonstrate how CEA experiments are conducted using grow tents with manually controlled red, blue, and white LED lights and fans. We have a shadecloth covered PVC pipe box with red and blue photoselective shadecloths and LED light placements on top, sides, and intracanopy to explain light spectrum and light placement. The Lunar/Martian greenhouse model displays an example of how plants could be grown on extraterrestrial bodies such as the moon and Mars. The display shows a cutaway view of a greenhouse installed below the soil surface for protection from radiation. Natural light is supplied with light pipes and artificial light is supplied with LEDs. Our lab’s table displays have been well received by people stopping by our tables. The campus events provide the opportunity for students to assist in staffing the tables and talking about CEA and their research. We also discuss CEA research opportunities provided by the UHM Undergraduate Research Opportunities Program (UROP) and the UHM Hawaii Space Grant Consortium Program.

Speakers

Kent D. Kobayashi

Associate Professor, TPSS Dept., Univ. of Hawaii at Manoa

Co-authors

Brylin Nelson

Univ of Hawaii at Manoa

Jonathan Kobayashi

University of Hawaii at Manoa

Tuesday September 24, 2024 5:10pm - 5:20pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

5:20pm HST

TECH - Rapid Detection of Herbicide-Resistant Weeds Utilizing Novel Full-Spectrum Imaging and a Hyperparameter-Tuned Convolutional Neural Network (CNN)

Tuesday September 24, 2024 5:20pm - 5:30pm HST

South Pacific 2

Every year, farmers around the world lose more than $95 billion from uncontrolled weed infestation. Herbicide-resistant weeds, also known as “superweeds”, are fast becoming a significant part of this weed problem and are a significant threat to crop production and food security. Late detection of resistant weeds leads to increasing economic losses and severe environmental damage. Traditionally, genetic sequencing and herbicide dose-response studies are used to detect herbicide-resistant weeds, but these are expensive and slow processes. To address this problem, an AI-based superweed identifier program (SIP) was developed to quickly and accurately distinguish herbicide-resistant from susceptible chickweed (Stellaria media). A regular camera was converted to capture light wavelengths from 300 to 1,100 nm. These full spectrum images were used to develop a hyperparameter-tuned convolutional neural network (CNN) model utilizing a “train from scratch” approach. This novel approach exploits the subtle differences in the spectral signature of resistant and susceptible chickweed plants as they react differently to herbicide treatments. The SIP was able to identify resistant chickweed to acetolactate synthetase (ALS) inhibitor herbicides as early as 72 hours post treatment at an impressive accuracy of 85%. It has broad applicability due to its ability to distinguish resistant from susceptible chickweed plants regardless of the type of ALS herbicide or dosage rate used. Utilizing the superweed identifier program will allow farmers to make timely interventions and develop more effective and safer weed management practices. This can optimize yield, reduce herbicide use, minimize environmental harm, prevent herbicide-resistant weed proliferation, and improve overall public health.

Speakers

Pauline Victoria Estrada

Student, Clovis North High School/Fresno State University

Co-authors

Anil Shrestha

Fresno State University

Tuesday September 24, 2024 5:20pm - 5:30pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

5:30pm HST

TECH - Puʻuhonua Kauluwehi: Maui Wildfire Rapid Response Strategies for Agroecosystem Resilience and Community Well-Being

Tuesday September 24, 2024 5:30pm - 5:40pm HST

South Pacific 2

The Puʻuhonua Kauluwehi project aims to develop a rapid response to the recent Maui wildfires by collaboratively establishing a network of biocultural refuges supporting the cultivation of native plants to accelerate landscape-scale agroecological resilience, food security and community well-being strategies. Puʻuhonua Kauluwehi is a Hawaiian phrase describing regenerative agroecosystem areas that provide shelter for native vegetation, attract native birds and insects, and serve as a source of thriving launching points to revegetate the landscape through community engagement. In Hawaiʻi, establishing biocultural refuges is even more critical as the unique ecosystems of the islands continue to come under threat from invasive species, drought, commercial development, lack of ecosystem management and are more at risk due to the dependence on imported response and aid resources from the mainland as demonstrated by the devastating impact of the Maui wildfires in August 2023. The project’s specific objectives are to: (1) Provide applied research and GIS mapping services that integrate water quality testing, soil testing and native plant and tree cataloging in one accessible database for the growing coalition of local agricultural and conservation organizations responding to the wildfires; (2) Develop strategies to ensure all children, youth, and adults have access to abundant local food during and after wildfire disasters through a network of seed orchard, seed bank, nursery and food hub partners; and (3) Design extension and non-formal community education initiatives to address the health and well-being of children, youth, and adults affected by wildfire disasters through work-based agroecosystem and stewardship training in the Kauluwehi Biocultural Garden for 300 participants. The Puʻuhonua Kauluwehi restoration project, led by University of Hawaii Maui College, will share initial outcomes of launching a technology platform to connect critical nodes of the Maui wildfire response into a thriving network that will serve as a social-ecological incubator for the positive impact of vibrant and culturally authentic landscapes and redefine the value of agroecosystems in Maui’s unique context for disaster recovery.

Speakers

Nicolette van der Lee

Program Manager, University of Hawaii Maui College

Tuesday September 24, 2024 5:30pm - 5:40pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

5:40pm HST

TECH - Enhancing Hot Pepper Quality and Yield through Smart Irrigation Strategies

Tuesday September 24, 2024 5:40pm - 5:50pm HST

South Pacific 2

Hot peppers (Capsicum chinense) are attracting increasing attention due to their rich reservoirs of secondary metabolites, notably capsaicinoids, which are in high demand across various industries such as culinary, cosmetic, and pharmaceutical. Consequently, there has been a surge in the number of new pepper growers emerging throughout the United States. Despite ranking fifth in pepper production, North Carolina’s pepper cultivation remains smaller compared to other states known for hot pepper production. Additionally, the southern U.S. anticipates an increase in extreme weather events such as droughts and floods. Thus, there is a pressing need to identify the most suitable pepper cultivars and implement efficient production management practices tailored to local climatic conditions to maximize both crop production and quality. To address this need, the current study was conducted at Reid Greenhouse, North Carolina Agricultural

Speakers

Harmandeep Sharma

Co-authors

Edmond Kwekutsu

North Carolina Agricultural and Technical State University

Gregory Goins

North Carolina Agricultural and Technical State University

Harjot Singh

North Carolina Agricultural and Technical State University

William Randle

North Carolina Agricultural and Technical State University

Tuesday September 24, 2024 5:40pm - 5:50pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

5:50pm HST

TECH - Spraying Drone Efficiency: A Comparative Study of Application Rate and Surfactant Addition

Tuesday September 24, 2024 5:50pm - 6:00pm HST

South Pacific 2

Current agricultural practices are facing several challenges because of the use of large and heavy machinery used in the fields. The benefits of covering large areas to meet the time of spraying crops is becoming questionable because the heavy machinery (large self-propelled boom sprayers) also can cause soil compaction and require large amounts of fuel and technical labor to be operated. Moreover, spraying drones are emerging as a pivotal technology in modern agriculture. They serve multiple purposes, from measuring and understanding fields using sensor and camera-captured images to acting as spray applicators for a wide range of products e.g.,including herbicides, pesticides, fungicides, and fertilizers. As a novel technology, spraying drones overcome some of the challenges faced by traditional methods. For instance, they can initiate applications in specific areas that require treatment, thereby avoiding issues like soil compression and unnecessary use of cultivated areas. This enhances precision while reduces losses in the field. However, defining application rate and the impact of adjuvant products is still scarce in previous studies. Therefore, in this study, we analyzed whether the coverage area is influenced by application rates and surfactant addition. The study was conducted in a carrot crop field. Water-sensitive papers were placed on the top leaf and at the bottom of the plants to quantify the coverage area. The measured area comprised a swath of 40 feet and a drone route of 100 feet. Measurements were performed in 9 crop-rows, each row with three hydrosensitive papers spaced in 33 feet apart. A multirotor spraying drone XAG P100Pro with Atomized Nozzles was used to apply spraying rates of 5 and 10 gallons per acre, both with and without surfactant addition. Results showed more coverage area on the top leaf than at the bottom of the plants. Similarly, when 10 gallons per acre were applied, it produced a higher covered area. However, there was a difference when applied 10 gallons with and without adjuvant. By applying adjuvant, the trial proved more efficient in reaching the plants. Conversely, when 5 gallons were applied, the surfactant did not contribute to either the top leaves or bottom part. Therefore, our results are promising and contribute to the enhancement of technology in agricultural production. The insights allow from farms to research centers to improve the spraying drone application, guaranteeing a more sustainable environment.

Speakers

Lucas Sales

Research Assistant, University of Georgia

Co-authors

Luan Oliveira

University of Georgia

Marcelo Barbosa

University of Georgia

Regimar dos Santos

University of Georgia

Tuesday September 24, 2024 5:50pm - 6:00pm HST
South Pacific 2

Poster presentation (individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

7:59am HST

Technology Applications in Horticulture 1 (TECH 1)

Wednesday September 25, 2024 7:59am - 9:45am HST

South Pacific 2

Advanced 3D Imaging for High Throughput Phenotyping of Horticultural Crops - Yu Jiang
Integrating UAV Imagery and AI to Forecast Vidalia Onion Yield and Quality - Marcelo Barbosa
Deep Learning Application for Field Phenotyping of Shoot Structure in Grapevine - Soichiro Nishiyama
Investigation of Using Hyperspectral Vegetation Indices to Assess Brassica Downy Mildew - Bo Liu
Effect of Innovative Laser Labeling Technology on Fresh Produce Quality and Safety - Manreet Bhullar
Cover Crop Decision Support Tools: Exploring the new suite of online cover crop tools - Esleyther Henriquez Inoa
CFD-based aerodynamic analysis under high wind velocity environment for multiple greenhouses - Anthony Kintu

Moderator

Shunping Ding

Associate Professor, California Polytechnic State University

Wednesday September 25, 2024 7:59am - 9:45am HST
South Pacific 2

Oral Sessions, Technology Applications in Horticulture 1

SUBJECT Technology

8:00am HST

TECH 1 - Advanced 3D Imaging for High Throughput Phenotyping of Horticultural Crops

Wednesday September 25, 2024 8:00am - 8:15am HST

South Pacific 2

Understanding plant growth and development is crucial for insights into plant structure and function, and recent advancements in AI-driven 3D imaging technologies have revolutionized the acquisition and analysis of high-fidelity plant models. These technologies enable accurate and rapid measurement of phenotypic traits, aiding breeders in developing new varieties and helping horticulturists optimize production management. The overarching goal of this study was to establish an AI-based 3D imaging and analysis pipeline specifically designed for detailed examination of horticultural crops at the organ level within controlled environments. We developed a robotic platform equipped with a rotating base and a high-resolution camera mounted on a robotic arm, allowing comprehensive imaging from any angle around the plant. Utilizing this robot, we generated 3D models of 30 hemp plants from two growth-rate categories in controlled environments, on a weekly basis. An AI model was developed to segment these 3D models into stems, branches, and leaves. Morphological traits were extracted from each category of the segmented organs, including stem length (i.e., plant height), stem diameter, branch length, branch diameter, leaf number, leaf area, and leaf aspect ratio. These measurements contributed to a classification model capable of distinguishing between fast and regular growth rates. Experimental results showed that the 3D imaging-derived measurements were highly correlated with human-derived measurements. In addition, the extracted traits were used as quantitative descriptors to classify hemp cultivars with different growth rates in CEA. Therefore, the developed pipeline can be used as an effective and efficient tool for breeding programs and CEA production management in the future.

Speakers

Yu Jiang

Cornell University

Co-authors

Jonathan Moon

Cornell University

Larry Smart

Cornell University

Neil Mattson

Cornell University

Ruiming Du

Cornell University

Wednesday September 25, 2024 8:00am - 8:15am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

8:15am HST

TECH 1 - Integrating UAV Imagery and AI to Forecast Vidalia Onion Yield and Quality

Wednesday September 25, 2024 8:15am - 8:30am HST

South Pacific 2

Forecasting yield and quality of Vidalia onions allows the stakeholders to make decisions on the best time and place to harvest. While yield defines an important quantitative parameter, conversely, sweetness emerges as timely factor of quality. Traditionally, measuring these parameters requires a field team and routine laboratory for the assessments, making it a subjective, time-consuming, labor-intensive, costly, and not-scalable approach. However, image technology and artificial intelligence (AI)-based methods could improve decision-making strategies. In this study, we collected unmanned aerial vehicle (UAV) multispectral images of two Vidalia onions fields from crop establishment until the harvest date, totaling six sets of images for each field. Each flight was performed with approximately 15 days apart. At the harvest date, 50 samples were collected in each field to determine yield, while 10 samples were used for sweetness. To ensure the robustness of the dataset, both fields were combined into a single dataset. Consequently, we used machine learning (ML) algorithms to perform predictive models, namely multiple linear regression (MLR), random forest (RF), and support vector machine (SVM). The dataset was split into 70% and 30% for training and testing, respectively, and the predictions were performed using the test dataset. Regarding the assessment of the models, we used the metrics namely coefficient of determination (R2), mean absolute error (MAE), and root mean squared error (RMSE). The models with higher R2 and lower MAE and RMSE were the bests. Notably, the considerable correlation between yield and spectral data made the MLR model perform well as more complex models such as RF. Conversely, when there was a weak correlation between the sweetness and spectral data, RF model could perform much better. In short, both models (MLR, RF, and SVM) could perform well into a predictive model, which highlights the strength of spectral data for representing Vidalia onions either quantitative or qualitative parameters. Therefore, our study not only represents an innovation in the field of specialty crop production, but also brings ready-to-use solutions to improve the production process and introduce Vidalia onions into the concept of field technology.

Speakers

Marcelo Barbosa

University of Georgia

Co-authors

Luan Oliveira

University of Georgia

Lucas Sales

University of Georgia

Regimar dos Santos

University of Georgia

Wednesday September 25, 2024 8:15am - 8:30am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

8:30am HST

TECH 1 - Deep Learning Application for Field Phenotyping of Shoot Structure in Grapevine

Wednesday September 25, 2024 8:30am - 8:45am HST

South Pacific 2

In the cultivation of fruit trees and vines, plant architecture is a critical determinant of productivity. While there are considerable diversities in plant architecture, which can be modified through pruning in fruit production, a method for high-throughput measurement and recording of architecture has not yet been established, posing a limitation to research and development in this area. Here we evaluated Transformer-based architecture for detecting above-ground shoot network of grapevine in an outdoor vineyard condition. The problem here was defined as the detection of nodes (buds or branching points) and their physical relationships (internodes or edges) within plant images. We also developed an evaluation metric inspired by the inherent structure of plant shoots to efficiently smooth detected structures to more closely resemble realistic systems in plants. The proposed framework has been successfully applied to the detection task in outdoor condition with complex background. Through the application of this method, we have demonstrated that our proposed framework is capable of extracting topological parameters of dormant shoot architecture of grapevine that effectively models the shoot biomass in a large-scale vineyard.

Speakers

Soichiro Nishiyama

Kyoto University

Co-authors

Dario Guevara

Department of Viticulture

Guillermo Garcia Zamora

Department of Viticulture

Mason Earles

Department of Viticulture

Wednesday September 25, 2024 8:30am - 8:45am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

8:45am HST

TECH 1 - Investigation of Using Hyperspectral Vegetation Indices to Assess Brassica Downy Mildew

Wednesday September 25, 2024 8:45am - 9:00am HST

South Pacific 2

Downy mildew, caused by Hyaloperonospora parasitica, poses a significant threat to Brassica oleracea crops, leading to substantial reductions in yield and marketability. This study seeks to assess various vegetation indices for detecting different levels of downy mildew infection in a Brassica variety, Mildis, using hyperspectral data. Through artificial inoculation with H. parasitica sporangia suspension, distinct levels of downy mildew disease were induced. Spectral measurements, ranging from 350 nm to 1050 nm, were performed on the leaves under controlled environmental conditions, and reflectance data were collected and processed. The Successive Projections Algorithm (SPA) and signal sensitivity calculations were employed to identify the most informative wavelengths, which were then used to develop Downy Mildew Indices (DMI). A total of 37 existing vegetation indices and three proposed DMIs were evaluated to assess downy mildew infection levels. The results revealed that a support vector machine achieved accuracies of 71.3%, 80.7%, and 85.3% in distinguishing healthy leaves from those with early (DM1), progressed (DM2), and severe (DM3) infections, respectively, using the proposed downy mildew index. The development of this novel downy mildew index has the potential to facilitate the creation of an automated monitoring system for downy mildew and aid in resistance profiling in Brassica breeding lines.

Speakers

Bo Liu

California Polytechnic State University

Co-authors

Marco Fernandez

California Polytechnic State University

Shunping Ding

California Polytechnic State University

Taryn Liu

California Polytechnic State University

Wednesday September 25, 2024 8:45am - 9:00am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

9:00am HST

TECH 1 - Effect of Innovative Laser Labeling Technology on Fresh Produce Quality and Safety

Wednesday September 25, 2024 9:00am - 9:15am HST

South Pacific 2

Introduction: Fresh produce is commonly associated with foodborne disease outbreaks and food recalls. To prevent the lethal impact of outbreaks, effective traceability is crucial. Produce items are traditionally labeled with price lookup (PLU) stickers. However, those stickers are environmental hazards, and frequent detachment of PLU stickers losses the information for traceability. Purpose: To investigate the effect of postharvest quality and microbial safety of laser labeling on fresh produce. Methods: Three horticultural crops, apple ‘Red Delicious ‘apple, cucumber, and green bell pepper, were procured from a local grocery store. Each produce was printed with a Quick Response (QR) code or text code using the laser engraver machine, followed by the application of edible wax. All produce was stored at 4° C temperature and 90% relative humidity during the study period. The postharvest quality was measured through fresh weight loss, QR code readability, and visual quality for 16 days. In another study, the laser-labeled produce was assessed for microbial contamination by quantifying artificially inoculated rifampicin-resistant E.coli (ATCC 25922) at an initial concentration of 106 CFU/mL. The experiment had five treatments: QR-coded labels followed by waxing or no wax, text-coded labels followed by waxing or no wax, and nontreated control. Results: Fresh weight loss for laser-printed produce was slightly higher than the nontreated control, but no difference in visual quality ratings was observed compared to the control. The population of rifampicin-resistant E.coli was statistically higher in all three produce labeled with text code compared to the nontreated control. However, QR-coded treatments were similar in the control. The application of wax did not facilitate microbial attachment. Significance: Laser labeling technology did not deteriorate the postharvest quality and susceptibility to microbial contamination. Hence this technology has the potential in commercial application as a better alternative to the PLU sticker to improve traceability.

Speakers

Manreet Bhullar

Kansas State University

Co-authors

Durga Khadka

Kansas State University

Eleni Pliakoni

Kansas State University

Majid Jaberi Douraki

Kansas State University

Patrick Abeli

Kansas State University

Xuan Xu

Kansas State University

Wednesday September 25, 2024 9:00am - 9:15am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

9:15am HST

TECH 1 - Cover Crop Decision Support Tools: Exploring the new suite of online cover crop tools

Wednesday September 25, 2024 9:15am - 9:30am HST

South Pacific 2

Cover crop recommendations can be complex based on regional factors and different growing conditions. In order to combat these challenges, the Precision Sustainable Agriculture team (PSA) developed online tools that are readily available for producers to help them optimize cover crops on their operation. Tools include a species and variety selector tool, seeding rate calculator, nitrogen calculator, and economic decisions tool. These platforms look to help producers find success with cover crops that fit their operation’s needs.

Speakers

Esleyther Henriquez Inoa

Research Assist., North Carolina State University

Technologies in agriculture and Cover Crop breeding.

Co-authors

Steven Mirsky

USDA ARS BARC

Wednesday September 25, 2024 9:15am - 9:30am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

9:30am HST

TECH 1 - CFD-based aerodynamic analysis under high wind velocity environment for multiple greenhouses

Wednesday September 25, 2024 9:30am - 9:45am HST

South Pacific 2

In South Korea, approximately 65% of the land is mountainous or forested, which limits large-scale farming. Over 53,000 ha of land has been reclaimed from the sea and dedicated to the development of large-scale indoor agricultural complexes. Given the coastal climatic conditions and flat nature, these areas present unique challenges including stronger winds and colder temperatures compared to the inland, leading to high air velocities and operation costs in naturally ventilated greenhouses. Aerodynamic analysis is necessary to estimate crop risk factors and identify potential aerodynamic problems before the construction of these structures. Traditional studies have focused on using natural ventilation rates to estimate greenhouse suitability for plant growth. However, under scenarios of high wind velocity, this approach has critical limitations in accounting for crop damage resulting from high air velocity induced inside naturally ventilated facilities. This is tailored to the fact that ventilation efficiency in naturally ventilated structures increases with an increase in air velocity. High wind velocity induced inside greenhouses is associated with rapid CO2 depletion, stomatal dysfunction, leaf abrasion, mechanical stress etc., which critically affect crop yield and biomass development. Under high wind environment, crop damage resulting from high internal air velocities is an important factor that needs to be accounted for during design of indoor agricultural facilities. This study introduces a CFD model for designing greenhouse complex including multiple greenhouses and model analysis approach. We developed the Aerodynamic Crop Damage Index (ACDI), used it to analyze the model, and compared it to the convectional ventilation efficiency approach. The ACDI revealed a 2.2-fold variation in damage potential based on the greenhouse's location within the complex and a 15-fold variation attributable to wind direction, pinpointing significant damage risks in zones with the highest and lowest air velocities. In contrast, the convectional ventilation efficiency method only identified damage risks in low-velocity areas. ACDI has not only the potential to account for high air velocity effects in naturally ventilated greenhouses but also presents an opportunity for specialized greenhouse complex control and management according to greenhouse position and incoming wind direction. Future research should aim at refining the ACDI for better aerodynamic analysis in greenhouse complexes planning and its integration into greenhouse ventilation control systems.

Acknowledgments: This work was supported by “Regional Innovations Strategy (RIS)” through the National Research Foundation of Korea (NRF) funded by Ministry of Education (MOE) (2024RIS-008)

Speakers

Anthony kintu Kibwika

phd student, Jeonbuk National University, Korea

Co-authors

Hyo-Jae Seo

Il-Hwan Seo

Wednesday September 25, 2024 9:30am - 9:45am HST
South Pacific 2

Oral presentation (Individual talk), Technology Applications in Horticulture 1

SUBJECT Technology

9:59am HST

Consumer Horticulture and Master Gardeners 1 (CHMG 1)

Wednesday September 25, 2024 9:59am - 11:45am HST

South Pacific 2

Fruit Classes Teach Invasive Species Management and IPM Practices to Homeowners, Master Gardener Volunteers, and Pesticide Applicators - Kaydie McCormick
Invasive Potential of Ornamental Landscape Plants in Southern Arizona - Michael Chamberland
Education on Water Saving Landscaping Practices Results in Measurable Water Conservation - Tiare Silvasy
Cultivating Connections: Empowering Professionals through NC Farm to School Training Initiative - Liz Driscoll
The gARTening Program: Fostering Community Engagement through Innovative Education - Clarissa Chairez
Welcome Home to Gardening in Tennessee: Reaching New Audiences with New Collaborative Outreach Models - Natalie Bumgarner
Enhancing Backyard Fruiting Cultivation Efficacy Through Florida-Friendly Landscaping™ Techniques for Homeowners - Brittany Council-Morton

Moderator

Kaydie McCormick

University of Florida Institute of Food and Agricultural Sciences

Wednesday September 25, 2024 9:59am - 11:45am HST
South Pacific 2

Oral Sessions, Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

10:00am HST

CHMG 1 - Fruit Classes Teach Invasive Species Management and IPM Practices to Homeowners, Master Gardener Volunteers, and Pesticide Applicators

Wednesday September 25, 2024 10:00am - 10:15am HST

South Pacific 2

Florida's diverse climate offers ample opportunities for cultivating various fruit crops, especially as traditional citrus faces disease challenges. However, accessible information on alternative fruit crops is limited. In response, a series of online classes was initiated in 2020 to address this gap, coinciding with the need for Continued Education Units (CEUs) for pesticide license holders during COVID-19 lockdowns. The objectives of the class series were threefold: to enhance knowledge of fruit crop cultivation in Central Florida, promote the adoption of Best Management Practices (BMPs) in crop selection and care, and provide CEUs for pesticide license holders in Florida. In its pilot year, three Extension Agents developed a five-week class, expanding to a six-week series in 2021 involving five Agents across three counties. Each session focused on BMPs for landscapes and the cultivation of at least three different fruit crops, including discussions on potential invasive pests as well as alternatives to invasive fruit trees that shouldn’t be planted. The classes were conducted via Zoom and archived on YouTube for wider accessibility. Evaluation of the program included a post-class survey to assess knowledge gain and a three-month follow-up to measure the adoption of practices. Over the course of 2020-2023, the series covered care techniques for 29 different fruit crops. The impact of the classes has been significant. Since 2020, 23 episodes have been produced, attracting a total of 2,015 live viewers. Participants earned a total of 361 CEUs. Survey results indicated a substantial knowledge gain, with 96% (1,480/1,540) of respondents reporting increased understanding of the material. Moreover, 79% (195/248) of respondents adopted at least one new Integrated Pest Management (IPM) strategy after taking the class. According to that same survey 48% (98/202) have altered turf to fruit trees, planting a total of 37,477 square feet with edible plants. In summary, the online class series successfully addressed the demand for information on alternative fruit crops in Florida while providing valuable CEUs for pesticide license holders. Its impact is evidenced by increased knowledge among participants and tangible changes in cultivation practices towards more sustainable and diverse fruit production.

Speakers

Kaydie McCormick

University of Florida Institute of Food and Agricultural Sciences

Co-authors

Morgan Pinkerton

UF/IFAS Extension Seminole County

Tiare Silvasy

UF/IFAS Extension Hillsborough County

Tina McIntyre

UF/IFAS Extension Seminole County

William Lester

UF/IFAS Extension Hernando County

Wednesday September 25, 2024 10:00am - 10:15am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

10:15am HST

CHMG 1 - Invasive Potential of Ornamental Landscape Plants in Southern Arizona

Wednesday September 25, 2024 10:15am - 10:30am HST

South Pacific 2

Plants introduced through ornamental horticulture have contributed to exotic species invasions around the world. Fifteen landscape plants commonly used in horticulture in southern Arizona have been evaluated using the Plant Risk Evaluator (PRE) tool developed by PlantRight and Cal-IPC. The evaluations have recognized eight of these species as presenting high potential risk of escaping cultivation and becoming invasive in Arizona. The process of evaluating ornamentals has fostered communication and collaboration between invasive species managers and Extension horticulture agents, who previously had little interaction. The findings have been communicated through several articles on invasive species in the trade magazine, Southwest Horticulture. This information has contributed to two cultivated species (Searsia lancea and Ulmus pumila) and the entire genus Tamarix being newly added to the Arizona State Noxious Weed List. Arizona Master Gardeners have been educated on invasive plant issues to foster outreach to the public and to aid their planting choices.

Speakers

Michael Chamberland

University of Arizona

Wednesday September 25, 2024 10:15am - 10:30am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

10:30am HST

CHMG 1 - Education on Water Saving Landscaping Practices Results in Measurable Water Conservation

Wednesday September 25, 2024 10:30am - 10:45am HST

South Pacific 2

Florida is facing critical water scarcity due to population growth. The home landscape is an opportune setting to make changes in practices to conserve water. Extension programs on water conservation in the landscape can provide residents with the information they need to adopt new practices to conserve water. In 2021-2023, UF/IFAS Extension residential horticulture programs in Central Florida, educated 6,474 residents about sustainable landscape practices. Based on client self-reported follow-up surveys (n=342), the annual water savings due to adoption of best landscaping practices was approximately 11.6 million gallons. It saved homeowners $49,977 in utility bills (based on regional value of $4.30 per 1,000 gallons). The most adopted practices included calibrating sprinkler systems to deliver ½ inch to ¾ inch of water instead of 1 inch, reducing irrigation frequency during summer, and reducing irrigation frequency during winter. Adoption is lower for water conservation practices that require installing soil moisture sensors and converting or installing irrigation spray heads. Participants reported (n=342): 35% eliminated irrigation or converted to low volume irrigation, 46% reduced irrigation from 3 to 2 days per week, 45% reduced irrigation frequency in winter, 46% reduced irrigation frequency in summer, 25% using a working rain shutoff device, 37% calibrated irrigation to ½” or ¾” rather than 1” or more. Impacts of changes in household water use multiply when life cycle assessment of a water supply system is considered. The reduction of 11.6 million gallons of residential water use resulted in saving 40,022 kWh of energy and $30,162 in treating and delivering water to the end users, reducing 28 metric tons of carbon dioxide equivalent of greenhouse gas emissions, deferring the need for $98,734 investment in alternative water supply infrastructure, and potentially reducing stormwater runoff and avoiding water quality deterioration. The impacts of these water conservation efforts are even greater than the values represented here based on total program attendance. This shows the efforts of extension agents educational programs resulted in measurable water savings to help Florida households conserve water.

Speakers

Tiare Silvasy

University of Florida

Wednesday September 25, 2024 10:30am - 10:45am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

10:45am HST

CHMG 1 - Cultivating Connections: Empowering Professionals through NC Farm to School Training Initiative

Wednesday September 25, 2024 10:45am - 11:00am HST

South Pacific 2

As the Farm to School movement continues to gain momentum, professionals in education, agriculture, and public health are seeking innovative ways to integrate this holistic approach into their practices. In North Carolina, our local, regional, and statewide food system has strengths across various sectors. Local agencies and community organizations now have decades of experience partnering together to maximize opportunities for local farmers and local food businesses. Partnering together, these food system practitioners have clearly begun to see that a systems approach is vital to supporting all sectors and stakeholders, vital to addressing the deep roots of inequity that negatively impacts our communities of color and particularly our children. The central need is in how to facilitate integrated efforts–both across farm to school components and also with multi-sector stakeholders–given that research shows that integration of farm to school programming brings the longest and most significant health and learning impacts on children. Our approach has been to develop the North Carolina Farm to School Training Initiative, a rich space of collaboratively created online content that informs and educates across the farm to school program areas. Through a combination of interactive modules, case studies, and expert-led discussions, our first course, School Gardening, provided participants with the knowledge and skills needed to navigate the complexities of Farm to School programming. The results from surveying pilot participants suggest numerous impacts, both on an individual and community level. Preliminary results found participants increased their knowledge and gained a deeper understanding of farm-to-school initiatives, including building community engagement through school garden teams, integrating gardening into curriculum, and the horticulture knowledge to successfully grow a garden. Participants improved their practical skills such as gardening techniques and the application of educational programming in the garden. Part of the course included interactive discussion boards and a qualitative review showed a number of themes emerged including that the course participants strongly benefitted by connecting with a group of like-minded educators and community organizers by fostering collaboration and support for farm-to-school efforts. Community engagement was another emergent theme with participants and they named that they would like to become more involved in their local food systems, finding connections with community partners like growers and Extension for access to resources and materials. These results suggest that fostering a community of practice that transcends geographic boundaries and provides localized and engaging content has significant potential to support great professional engagement in farm to school.

Speakers

Liz Driscoll

Extension Associate, NC State University/ NC Cooperative Extension

Co-authors

Kirsten Blackburn

NC State University

Remi Ham

NC State University

Wednesday September 25, 2024 10:45am - 11:00am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

11:00am HST

CHMG 1 - The gARTening Program: Fostering Community Engagement through Innovative Education

Wednesday September 25, 2024 11:00am - 11:15am HST

South Pacific 2

Orange County, Florida, an urban county with a boasting a population of 1.4 million residents, faces a distinctive demographic trend with a homeowner rate of 56%, notably below the national average of 64%. This indicates a higher proportion of renters and apartment dwellers within our community. In order to expand the reach of our horticultural efforts beyond the limitations of traditional homeownership and include all residents, our Master Gardener Volunteer Program developed the Garden Art (gARTening) program, aimed to appeal to a wider audience. Beyond mere attraction of new attendees, our focus was to increase: office foot traffic, awareness of UF/IFAS Extension Services, and create a unique hands-on program that maintained affordability while generating revenue. We developed "The gARTening Program," featuring unique garden-related art projects, to achieve our objectives. Classes ranged from 1-2 hours and $5-35, with topics such as terrariums, kokedamas, pressed flower art, and more. Collaborating with Master Gardener Volunteers (MGVs), we created educational materials such as PowerPoints, handouts, and economical shopping lists. Our diverse approach attracted a broad audience, including young families, mother-daughter pairs, couples, and individuals, fostering inclusivity and engagement. The outcomes of the gARTening Program exceeded expectations: • Revenue generated in one year: $3200 • 47% of participants were new to UF/IFAS Extension and had never utilized our services before. • 70% joined due to the unique hands-on experience. • 95% indicated they gained knowledge of UF/IFAS Extension services as a result of attending the workshop. • Additionally, participants showed continued engagement, with many signing up for additional classes, volunteering with 4-H or becoming an MGV, and promoting our services to others. The gARTening Program not only met, but surpassed its objectives, illustrating its efficacy in community engagement and revenue generation. By offering unique experiences, we heightened awareness of UF/IFAS Extension Services, attracting new participants and fostering long-term engagement. The program's success underscores the potential for innovative education methods to address funding challenges while advancing community outreach and awareness. This model holds broader implications for enhancing community well-being and supporting sustainable organizational growth.

Speakers

Clarissa Chairez

Extension Faculty, UF/IFAS Extension Orange County

Wednesday September 25, 2024 11:00am - 11:15am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

11:15am HST

CHMG 1 - Welcome Home to Gardening in Tennessee: Reaching New Audiences with New Collaborative Outreach Models

Wednesday September 25, 2024 11:15am - 11:30am HST

South Pacific 2

New residents in the state along with new gardeners are an increasingly large Extension audience. As our Extension horticulture team discussed the challenges in individually addressing these questions and meeting the needs of these new stakeholders, we realized new models and resources were needed. While Extension has a great array of publications and resources on lawns, landscapes and gardens, there wasn’t a publication that provided a good entry point for those new to the region or gardening. So, we set out to develop a ‘gateway publication’ to provide a general overview and connect folks to further resources without being overwhelming. A magazine format with easy to digest 2-page spreads on the most common areas of gardening was developed titled “Welcome Home: Gardening in Tennessee.” To extend the reach and impact of this new resource and engage Extension agents and stakeholders across the state, our horticulture team developed a new outreach program that paired live, distance teaching with local hands-on labs and activities. In October of 2023, we had a 5-session workshop series where new residents could come to their local office for an hour of teaching from our best horticulture content folks and then take part in a hands-on teaching demonstration with their local agriculture Extension agent. Nearly 300 participants in 32 counties took part in the series. Evaluation data revealed that over 70% of attendees had attended no or very few prior Extension programs. With a fee of only $30-50 locally, attendees reported a value of over $950 received from information delivered in the class. This presentation will focus on the novel delivery model and evaluation data along with perspectives on opportunities and challenges in reaching these new Extension audiences.

Speakers

Natalie Bumgarner

Assistant Professor, University of Tennessee Knoxville

Co-authors

Andrea Ludwig

University of Tennessee

Anna Duncan

University of Tennessee

Celeste Scott

University of Tennessee

Gregg Upchurch

University of Tennessee

Haley Treadway

University of Tennessee

Justin Stefanski

University of Tennessee

Lee Rumble

University of Tennessee

Melody Rose

University of Tennessee

Mitchell Mote

University of Tennessee

Seth Whitehouse

University of Tennessee

Taylor Reeder

University of Tennessee

Virginia Sykes

University of Tennessee

Wednesday September 25, 2024 11:15am - 11:30am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners

11:30am HST

CHMG 1 - Enhancing Backyard Fruiting Cultivation Efficacy Through Florida-Friendly Landscaping™ Techniques for Homeowners

Wednesday September 25, 2024 11:30am - 11:45am HST

South Pacific 2

Florida's distinctive subtropical climate renders it a haven for the average backyard gardener. Yet, numerous homeowners grapple with challenges in cultivating dooryard fruits, often due to incorrect planting times or a dearth of expertise. Recognizing this, the University of Florida/Institute of Food & Agricultural Sciences (UF/IFAS) has introduced the Florida-Friendly Landscaping TM program, illuminating nine core principles. These guidelines equip homeowners with the necessary methods and techniques to optimize plant growth and development. As we continue to increase resident population daily from various parts of the world, educating homeowners on these principles, can significantly elevate their chances of realizing their cultivation aspirations.
To meet the persistent demand for edible landscapes, a series of enlightening workshops unfolded across Flagler, Putnam, and Volusia counties. These sessions honed in on sustainable management strategies tailored for cultivating delectable fruits like blackberries, mulberries, goji berries, and citrus varieties. Spanning two to three hours, participants delved into a comprehensive curriculum covering optimal planting and harvest timings, varietal nuances, cultivation methodologies, fertilizer selection, integrated pest management protocols, and the significance of hardiness zones. These workshops roamed through the tri-county region, shining a spotlight on local agricultural enterprises engaged in the production or promotion of sought-after backyard fruits.

This collaborative initiative not only bolstered our overarching educational goals but also catalyzed a surge in agrotourism intrigue. As each program reached its conclusion, attendees departed armed with two plants of their preference and a wealth of resources, poised to lay down the groundwork for thriving cultivation endeavors.
22 Program participants indicated the following as measured via post evaluation survey:
Participants indicated a 73% (n=16) implementation plan for Florida-Friendly Landscaping TM (FFL) principle of "Right Plant Right Place” as they continue in their gardening endeavors.
Participants indicated an 82% (n=18) knowledge gain on cultivar selection, soil testing, and importance of fertilization.
64% (n=14) of program participants shared a plan to continue backyard fruit production using the information disseminated during this program.

Speakers

Brittany Council-Morton

UF/IFAS Volusia County Extension

Co-authors

Claude Judy Jean

University of Florida

Wednesday September 25, 2024 11:30am - 11:45am HST
South Pacific 2

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners
Agricultural Sciences (UF/IFAS) 16) implementation plan for Florida-Friendly Landscaping TM (FFL) principle of "Right Plant Right Place” as they continue in their gardening endeavors. Participants indicated an 82% (n=18) knowledge gain on cultivar selection, soil testing, and importance of fertilization. 64% (n=14) of program participants shared a plan to continue backyard fruit production using the information disseminated during this program.

11:59am HST

Herbs, Spices, and Medicinal Plants (HSMP)

Wednesday September 25, 2024 11:59am - 1:10pm HST

South Pacific 2

Effects of Drought Stress on Secondary Metabolite Production and Yield in Ocimum Basilicum - Daniela Menendez
Effects of Thermal Processing and Drying on Nutritional Quality and Consumer Preference of Amaranthus viridis L. Value-added Product - Megan Reid
Ginseng Growth and Ginsenoside Contents According to Light Intensity - Minhee Kim
Evaluation of anticancer activity of perennial tree seed-derived extracts on various cancer cell lines - Hamin Lee
Exploring the Potential of Annonacin and 2-Deoxy-D-glucose on Non-Small Cell Lung Cancer Cells - Bhoj Raj Bhattarai
Responses and relationship between bioactive compounds and phenotypic traits in Dahurian angelica breeding lines - Eun Jeong Koh
Effects of Foliar Application of Humic Acid and NPK Fertilizers to the Soil on Important Growth Indices of Black Mustard - Keefah Al-Garallaa
Assessment of micropropagated ginger cultivars and generations on plant growth and rhizome yield in a greenhouse - Guochen Yang

Moderator

Keefah AL-Garallaa

Mississippi State University

Wednesday September 25, 2024 11:59am - 1:10pm HST
South Pacific 2

Poster Session, Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:00pm HST

HSMP - Effects of Drought Stress on Secondary Metabolite Production and Yield in Ocimum Basilicum

Wednesday September 25, 2024 12:00pm - 12:10pm HST

South Pacific 2

Climate change makes water stress a more prominent obstacle to maintaining the same yield and quality of harvestable crop biomass for consumers, posing a unique challenge to farmers who must compete for clean water resources with other stakeholders. Thus, farmers must adapt their irrigation strategies to remain profitable and relevant. Basil is a tender perennial crop from the family Lamiaceae that is grown as a culinary herb and as a source of essential oils. Sweet basil (Ocimum basilicum) is a model crop for understanding water stress in economically important crops due to its intolerance to drought stress and its unique phytochemical properties. Sweet basil produces different concentrations of different secondary metabolites in response to abiotic stress, such as eugenol and methyl chavicol. This study seeks to understand what chemical and physical changes occur to sweet basil under water stress within a greenhouse environment. Three different treatments of water stress controlled via drip irrigation and a separate control group were used to analyze the yield and secondary metabolite production within sweet basil. Wet weight, dry weight, height, and phytochemical concentrations were calculated for the different drought treatments. There was a significant relationship between the final height, dry and wet yield, and chemical concentration of the different water stress treatments. One of the most interesting findings of the study was that the high note of sweet basil, a phenylpropanoid known as eugenol, was found in similarly high concentrations throughout the different treatment groups. There were significant differences in concentration across terpenoids such as eucalyptol, germacrene D, and linalool. This study showed that there were significant effects on the yield and concentration of phytochemicals produced by sweet basil from drought stress.

Speakers

Daniela Menendez

Florida International University

Co-authors

Diego Salazar Amoretti

Binghamton University

Krishnaswamy Jayachandran Jayachandran

Florida International University

Mahadev Bhat

Florida International University

Wednesday September 25, 2024 12:00pm - 12:10pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:10pm HST

HSMP - Effects of Thermal Processing and Drying on Nutritional Quality and Consumer Preference of Amaranthus viridis L. Value-added Product

Wednesday September 25, 2024 12:10pm - 12:20pm HST

South Pacific 2

Economic opportunities have arisen to increase the production of specialty crops catering to ethnically diverse consumers. Opportunities to capture anticipated niche market growth for ethnic crops continue to grow. Amaranthus viridis L. (amaranth), a highly nutritious leafy vegetable, eaten cooked or raw, with a nutritional value similar to spinach, is widely cultivated, highly nutritious, and has medicinal properties. Studies were conducted to 1) evaluate two thermo-processing (steam and water blanching) and three drying methods (freeze, hot air, and infrared drying) for the development of amaranth value-added products and 2) analyze the effective thermo-processing and drying methods to maximize the phytonutrient contents and minerals in the vegetable. Two thermo-treatments, steam blanch (SB) and hot water (HB), and the control (C), three drying treatments, freeze-dried (FD), hot air dried (HAD), and infrared dried (ID) were used. The treatments were T1:FD(C), T2:HAD(C), T3:ID(C), T4:FD(SB), T5:HAD(SB), T6:ID(SB), T7: FD(HW), T8: HAD(HW), T9: ID(HW). Amaranth was harvested once per week and processed three times throughout the growing season (1st harvest (28 days after transplanting (DAT)), 2nd harvest (56 DAT) in the middle of the growing season, and the 3rd harvest (84 DAT) at the end of the growing season). Phytonutrients, ascorbic acid and β-carotene, rehydration capacity, and sensory evaluation were analyzed. Significant differences in phytonutrients (total phenolic content (TPC) and total flavonoid content (TFC)) were observed among treatments and harvest times, with the FD(C) treatment being significantly higher in TPC and TFC during the 1st and 2nd harvest when compared to the other treatments. Ascorbic acid was significantly higher in FD(C) and HAD(C) (419.33 mg/100g, dm and 203.3 mg/100g, dm, respectively). ID(C), ID(SB), ID(HW) and HAD(SB) were significantly lower in ascorbic acid when compared to the other treatments. Significant differences were also observed in β-carotene among treatments. For rehydration capacity, rehydration at 9 minutes showed the highest water absorbance for all treatments, with FD(C) and HAD(C) being significantly higher, while HAD(HW) and ID(HW) were significantly lower in water absorbance for the rehydration times of 3, 6 and 9 minutes. For the sensory evaluation, 59%, 73%, and 54% of respondents indicated that the rehydrated samples were just right for flavor, color, and texture, respectively; and 45% of respondents indicated that the overall quality of the rehydrated sample was good. This study provides valuable insights for the development of value-added products catering to ethnically diverse consumers.

Speakers

MEGAN REID

University of Maryland Eastern Shore

Co-authors

Byungrok Min

University of Maryland Eastern Shore

Caleb Nindo

University of Maryland Eastern Shore

Corrie Cotton

University of Maryland Eastern Shore

Wednesday September 25, 2024 12:10pm - 12:20pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:20pm HST

HSMP - Ginseng Growth and Ginsenoside Contents According to Light Intensity

Wednesday September 25, 2024 12:20pm - 12:30pm HST

South Pacific 2

Ginseng (Panax ginseng C.A. Meyer) is mainly cultivated in the Republic of Korea and China, and has been traditionally used as a medicinal plant in East Asia for the treatment of diseases such as hypertension, diabetes mellitus, liver and kidney dysfunction, mental disorders, and skin inflammation. Ginseng roots are cultivated after maturing at 3 to 6 years of age. The harvested ginseng roots are consumed and sold in various forms of products, such as fresh ginseng, red ginseng, and white ginseng. Ginseng is a shade-tolerant crop and requires shading facilities. It grows well with a light intensity of 10%, but its growth is hindered at light intensity above 20% due to high temperature. Therefore, it is cultivated with a light intensity set to 10% from April to October and harvested in October. However, if early harvesting is done in August to increase farm income, growth is low due to insufficient light. Therefore, a cultivation experiment was conducted with the light intensity set to 10% and 20% for the August harvest, and the yield and ginsenoside contents were compared with the October harvest. The yield of the 20% light intensity treatment group was 665 kg/10a, whereas the yield of the 10% light intensity treatment group was 572 kg/10a. The yield of the 20% treatment group was 16.3% higher than that of the 10% treatment group. According to the analysis on nine ginsenoside components including Rg1, the total ginsenoside contents in the 20% light intensity treatment group was 27.51 mg/g, which was 75.3% higher than that of the 10% light intensity treatment group at 15.69 mg/g. Specifically, Rg1, Re, Rb1, and Rc were 3.40, 7.29, 7.93, and 3.84 mg/g, respectively, more than twice as high as those in the 10% light intensity treatment group. Conclusively, a light intensity of 20% was determined to be optimal for maximizing ginsenoside cultivation for August harvesting.

Speakers

Minhee Kim

South Korea, Ginseng&Medicinal Plant Research Institute, Chungcheongnam-do Agricultural Research and Extension Services

Co-authors

Bong Jae Seong

Ginseng

Ka Soon Lee

Ginseng

Sun Ick Kim

Ginseng

Yong Chan Park

Ginseng

Wednesday September 25, 2024 12:20pm - 12:30pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:30pm HST

HSMP - Evaluation of anticancer activity of perennial tree seed-derived extracts on various cancer cell lines

Wednesday September 25, 2024 12:30pm - 12:40pm HST

South Pacific 2

According to the WHO, the global cancer incidence rate is increasing by more than 5% annually due to the rapid increase in the elderly population and continuous environmental degradation. The increasing rate of cancer incidence underscores the importance of developing health supplements and pharmaceutical ingredients derived from plants. Indeed, several anticancer drugs such as Taxol, vincristine, and vinblastine have been developed from plant-derived ingredients, serving as crucial resources in modern pharmaceutical development. This study evaluated the anticancer activity of extracts from seven different seeds against various cancer cell lines. Seeds from perennial trees such as Alnus japonica, Chamaecyparis obtusa, Cornus kousa, Phellodendron amurense, Pinus densiflora, Prunus sargentii, and Quercus glauca were used in the experiments. Extracts, prepared via ultrasonic extraction with 70% ethanol and concentrated to 100 µg·mL-1, were tested on lung (A549), prostate (LNCaP-LN3), melanoma (B16F10), colon (Caco-2, HCT15), and breast (MDA-MB-231) cancer cell lines using the MTT assay. In the lung cancer (A549) cell line, C. kousa, C. obtusa, and Q. glauca significantly inhibited cancer cell proliferation compared to the negative control (DMSO), with viability rates of 68.2%, 6.8%, and 44.7%, respectively. Prostate cancer (LNCaP-LN3) cells showed anticancer activity with extracts from six species, excluding P. sargentii, in the following order of cell viability: C. obtusa (8.2%) > C. kousa (15.8%) > A. japonica (35.1%) > Q. glauca (73.9%) > P. amurense (78.6%) > P. densiflora (86.3%). Cell viability was assessed for colon cancer cell lines Caco-2 and HCT15, where extracts from C. kousa (71.7% for Caco-2 and 69.9% for HCT15), C. obtusa (8.0% for Caco-2 and 7.1% for HCT15), and Q. glauca (89.9% for Caco-2) demonstrated significant inhibition of cell proliferation. For melanoma (B16F10) and breast cancer (MDA-MB-231) cell lines, extracts from C. kousa (63.8% and 66.3%, respectively) and C. obtusa (6.7% and 7.3%, respectively) showed strong anticancer activity, significantly reducing cell viability. This study suggests that the extracts from seven species of seeds can have a potent anticancer effect on specific cancer cell lines and confirms their potential as an important step in the development of anticancer ingredients derived from perennial tree seeds.

Speakers

Hamin Lee

Chungbuk National University

Co-authors

Ju-Sung Cho

Chungbuk Nationl University

Kyungtae Park

Chungbuk Nationl University

Youg-Rak Kwon

National Forest Seed Variety Center

Wednesday September 25, 2024 12:30pm - 12:40pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:40pm HST

HSMP - Exploring the Potential of Annonacin and 2-Deoxy-D-glucose on Non-Small Cell Lung Cancer Cells

Wednesday September 25, 2024 12:40pm - 12:50pm HST

South Pacific 2

Annonacin is a natural compound found in the fruit of a number of members of the Annonaceae family, including soursop and Asimina triloba. This compound has promise in targeting vital metabolic pathways, inhibiting mitochondrial complex I, and exploiting the altered energy dynamics of cancer cells that lead to apoptosis. Non-small cell Lung Cancer (NSCLC) accounts for approximately 80% of all lung cancer cases and remains a leading cause of cancer-related mortality worldwide. Despite advancements in cancer treatment, the five-year survival rate of NSCLC is low, justifying the urgent need for innovative and effective therapeutic approaches. The aberrant energy metabolism, which is a hallmark of cancer, including NSCLC, known as the Warburg effect, makes it a potential target for therapeutic interventions. In addition, 2-Deoxy-D-glucose (2DG) is a glucose analog widely studied for its ability to target the glycolytic pathway of energy metabolism of cancer. The potential combination of Annonacin and 2DG acting synergistically to inhibit the growth of A549 NSCLC cells could lead to new treatment options. The objective of this study was to examine glycolytic and mitochondrial complex I inhibitors individually and in combination to target energy metabolism to inhibit A549 NSCLC cell growth as novel antitumor agents. The study was carried out in an in vitro model system using the A549 NSCLC cell line, where the NL20 Bronchial Epithelium cell line was used as a parallel control. Cells were treated with 0 µM, 2 µM, 4 µM, and 6 µM concentrations of Annonacin and 0 mM, 2.5 mM, 5 mM, and 10 mM concentrations of 2DG, both individually and in combination in triplicate experimental design with control. The MTT assay was employed to determine immediate cell viability and assess the applied treatment's cytotoxic effects. The oxidative stress in treated and control cells was determined through superoxide dismutase and glutathione peroxidase assays. Furthermore, the long-term proliferative capacity of the cells post-treatment was examined using a colony-forming assay. The implications of the combined application of 2DG and Annonacin on A549 NSCLC cell viability and potential as a treatment of NSCLC will be discussed. These findings need further investigation to elucidate the underlying mechanisms and explore the in vivo and clinical applicability details for the combined administration of Annonacin and 2DG's use in NSCLC treatment.

Speakers

Bhoj Raj Bhattarai

Kentucky State University

Co-authors

Avinash Tope

Kentucky State University

Cora Teets

Kentucky State University

Kirk Pomper

Kentucky State University

Dr. Kirk W. Pomper is the Professor of Horticulture in the College of Agriculture, Community, and the Sciences at Kentucky State University in Frankfort, Kentucky. As Horticulture Research Leader, his program is focused on research and Extension efforts toward developing pawpaw as... Read More →

Wednesday September 25, 2024 12:40pm - 12:50pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

12:50pm HST

HSMP - Responses and relationship between bioactive compounds and phenotypic traits in Dahurian angelica breeding lines

Wednesday September 25, 2024 12:50pm - 1:00pm HST

South Pacific 2

Dahurian angelica (Angelica dahurica (Fisch. ex Hoffm.) Benth.

Speakers

Eun Jeong Koh

Gyeongsangbuk-do Agricultural Research

Co-authors

Beong Sung Kim

Gyeongsangbuk-do Agricultural Research

Jiwon Kim

Gyeongsangbuk-do Agricultural Research

Joong Hwan Lee

Gyeongsangbuk-do Agricultural Research

Wednesday September 25, 2024 12:50pm - 1:00pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

1:00pm HST

HSMP - Effects of Foliar Application of Humic Acid and NPK Fertilizers to the Soil on Important Growth Indices of Black Mustard

Wednesday September 25, 2024 1:00pm - 1:10pm HST

South Pacific 2

Humic acid that improves plant growth and yield indices such as fresh and dry weights, plant height. Field experiment was conducted at the Al-Mussaib Technical Institute/Iraq during the 2022-2023 season to study the effect of adding NPK complex fertilizer to the soil and spraying with organic fertilizer (Humic acid) on the growth and yield of black mustard plants, according to a randomized complete block design (RCBD) with three replications. In this study, the effect of foliar application of Humic acid and/or fertilizers of NPK on the growth characteristics of black mustard (Brassica nigar) in field conditions were compared. According to the results, the foliar application of Humic acid The results were analyzed according to analysis of variance, and the means were compared using the least significant difference (LSD) test under the probability level of 0.05.A two-factor experiment (3×3) was carried out. The first factor was the addition of a balanced NPK complex fertilizer (20:20:20). At levels of (0, 30, or 60) kg/dunum in two batches, the first two weeks after germination, and the second when flowering begins. The fertilizer was placed about 10 cm under the plant in the furrows and covered with dirt, then watered after fertilization. The second factor was spraying with three concentrations of organic fertilizer (Humic acid) (0, 2, or 4) ml.l-1. It was observed from the results that adding NPK complex fertilizer and organic fertilizer (Humic acid) has a significant effect on the characteristics of vegetative growth, as is evident from the fact that the levels of NPK complex fertilizer and spraying with organic fertilizer (Humic acid) have a significant effect on the productive characteristics of the plant. It is conclude from this experiment that the most effective treatment that can be used to feed the black mustard plant under the conditions of this experiment, and which achieved the best results in improving the vegetative and productive characteristics of the plant, is the 60 kg overlap treatment. 1 dunam-1 NPK with spraying three times with 2 ml.l-1 of organic fertilizer (Humic acid), which improved the characteristics of vegetative growth and gave the highest rate of mustard number. Plant-1 and number of seeds. Mustard-1 and seed weight. Plant-1 and the amount of seed yield per dunum. application of 45 ppm humic acid with 60/kg – per dunum (per 2500 square meters) would be the best option to maintain better growth, yield and quality in black mustard.

Speakers

Keefah AL-Garallaa

Mississippi State University

Wednesday September 25, 2024 1:00pm - 1:10pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

1:10pm HST

HSMP - Assessment of micropropagated ginger cultivars and generations on plant growth and rhizome yield in a greenhouse

Wednesday September 25, 2024 1:10pm - 1:20pm HST

South Pacific 2

Our research demonstrated micropropagated ginger helped solve seed ginger sourcing issue for this “niche” market crop. Traditionally, farmers would save ginger rhizomes from the previous year’s harvest, store over winter, and then use as seeds for the upcoming growing season. This research was to determine if micropropagated ginger generations would affect ginger growth and yield. We studied nine ginger cultivars (BB, BG, BK, CW, HY, MD, PY, KY, and KM) from various tissue culture (TC) generations (TCF1, TCF2, TCF3, and TCF4). TCF1 seedlings were initially planted (March 2023), and then transplanted with TCF2, TCF3 and TCF4 from previous years’ study, into individual grow bags (May 2023) with one seedling per 10-inch grow bag (2:1 metro mix:compost). Plants were placed on a bench inside a greenhouse with a completely randomized design (CRD) with 20 cultivar/TC Generation combinations, 5 replications per cultivar/generation. We collected growth data (stem number, diameter, length, and SPAD), yield data (number of rhizome pieces per seedling, weight of individual rhizome piece/finger, weights of biological root, edible root and total rhizome weight), and PAR of individual plants. Data was then analyzed using SAS OnDemand for Academics with PROC GLM at the 0.05 level of significance. There was a significant effect as the number of TC generations increased, with stem length (TCF1 – 91.8, TCF2 – 91.0, TCF3 – 103.5, and TCF4 – 101.5 cm) and stem diameter (TCF1 – 6.2, TCF2 – 6.4, TCF3 – 8.1, and TCF4 – 8.1 mm) increasing, while number of stems (TCF1 – 19.0, TCF2 – 18.3, TCF3 – 10.4, and TCF4 – 9.9) decreased on average. TC generations had significant effect on rhizome yield. Individual pieces of ginger rhizome decreased in number (TCF1 – 37.9, TCF2 – 31.1, TCF3 – 28.9, and TCF4 – 28.0) but increased in size (weight) (TCF1 – 12.3, TCF2 – 16.8, TCF3 – 25.4, and TCF4 – 23.1 g) as number of TC generations increased. Similarly, biological root weight significantly decreased (TCF1 – 175.9, TCF2 – 195.3, TCF3 – 42.0, and TCF4 – 52.9 g). Edible root weight significantly increased (TCF1 – 443.9, TCF2 – 460.6, TCF3 – 700.6, and TCF4 – 641.0 g). There was a slight upward trend of rhizome yield as TC generations increased (TCF1 – 619.9, TCF2 – 671.3, TCF3 – 761.2, and TCF4 – 709.5 g).

Speakers

Guochen Yang

Co-authors

Daniel Tetteh

North Carolina A

Julia Robinson

North Carolina A

William Lashley

North Carolina A

Zipporia Moore

North Carolina A

Wednesday September 25, 2024 1:10pm - 1:20pm HST
South Pacific 2

Poster presentation (individual talk), Herbs; Spices and Medicinal Plants

SUBJECT Herbs Spices and Medicinal Plants

1:59pm HST

Hemp Research and Extension 2 (HEMP 2)

Wednesday September 25, 2024 1:59pm - 3:45pm HST

South Pacific 2

In-vitro Screening of Native Plant Crude Extracts Against Major Plant Pathogens Affecting Cannabis and Specialty Food Crops of Louisiana - Jennifer Blanchard
Investigating Fiber Hemp Seed Size Impact on Germination, Emergence, and Early Growth Rate - Samantha Carroll
Modified Media and Lighting for Repeated In Vitro Cutting Cycles of Cannabis Sativa - Molly McKay
Differential effects of macro- and micronutrients on secondary metabolite production in drug-type (medical) cannabis - Nirit Bernstein
QTL mapping and gene discovery for seed traits in hemp (Cannabis sativa L.) F2 mapping populations - Luis Monserrate
Dynamics of Cannabinoid Accumulation and Morphological Changes in Cannabis Inflorescences - Samuel des Bordes
Variable Planting Date Influences on Growth and Development of Floral Hemp in North Dakota - Brock Schulz

Moderator

Nirit Bernstein

Institute of Soil Water and Environmental Sciences, ARO, Volcani Research Center

Wednesday September 25, 2024 1:59pm - 3:45pm HST
South Pacific 2

Oral Sessions, Hemp Research and Extension 2

SUBJECT Hemp

2:00pm HST

HEMP 2 - Variable Planting Date Influences on Growth and Development of Floral Hemp in North Dakota

Wednesday September 25, 2024 2:00pm - 2:15pm HST

South Pacific 2

Commercially produced floral hemp (Cannabis sativa L.) is high in cannabidiol (CBD) concentrations relative to tetrahydrocannabinol (THC); this is intentional due to regulatory pressures requiring low THC thresholds. Given the predominant role of genotype in plant development, it is crucial to also explore environmental factors that may allow for optimization of hemp growth, yield, and quality. The goal in this study is to evaluate the extent to which an extended vegetative growing period has on height, width, and yield in irrigated raised bed production of floral hemp in North Dakota. To survey this relationship between planting date, growth, and quality parameters, mother plants were germinated from seed at the beginning of the growing season. Each treatment group of cuttings, separated by approximately two weeks, were excised from their respective cultivar mother plant for four timing treatment groups. Cultivars evaluated were ‘ACDC’, ‘Bubbatonic’, ‘Sour Elektra’, and ‘Umpqua’. The main effect of cultivar did not significantly affect any measured parameters except for height and the top 1/3 portion of dry floral biomass. Planting date treatments significantly affected the wet weight of total above-ground biomass, total dry above-ground biomass, and total floral biomass. Average total above-ground biomass and dry floral biomass was statistically different for each planting date except for the last two planting dates (June 19 and July 3). Total above-ground dry biomass averaged over cultivars, were 4070 g, 2432 g, 1323 g, and 894 g, for dates May 19, June 5, June 19, and July 3, respectively. Mean yields for total dry floral biomass, averaged over cultivars, were 1779 g, 1279 g, 784 g, and 535 g, for dates May 19, June 5, June 19, and July 3, respectively. Earlier planting dates showed an increase in height for three of the four cultivars with the exception of ‘Umpqua’. A cultivar interaction with planting date treatment occurred for the top 1/3 portion of dry floral biomass and indicated that earlier planting date increased the biomass for ‘Bubbatonic’ and ‘Sour Elektra’ while planting date did not influence dry biomass for ‘ACDC’ and ‘Umpqua’. The insights gained from assessing the impact of variable vegetative growing periods on growth and quality parameters of photoperiod-dependent floral hemp could have broader implications for optimizing production practices. Understanding the intricate interplay between genotype, environmental factors, and cultivation practices is essential for advancing sustainable and efficient hemp cultivation strategies.

Speakers

Brock Schulz

North Dakota State University

Co-authors

Collin Auwarter

North Dakota State University

Harlene HattermanValenti

North Dakota State University

Wednesday September 25, 2024 2:00pm - 2:15pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

2:15pm HST

HEMP 2 - In-vitro Screening of Native Plant Crude Extracts Against Major Plant Pathogens Affecting Cannabis and Specialty Food Crops of Louisiana

Wednesday September 25, 2024 2:15pm - 2:30pm HST

South Pacific 2

Louisiana’s hot and humid climate provides the perfect environmental conditions for the growth of fungal and bacterial plant pathogens. These fungal infections are an obstacle to the success of commercial production of Cannabis sativa in the state. Two of the most recent and significant fungal diseases are southern blight caused by Sclerotium rolfsii and stem canker caused by Botrytis cinerea. However, there is a lack of formal and professional knowledge regarding fungi that infect medicinal hemp plants, and practical and effective methods for managing the casual agents of these diseases. The objective of this study was to identify natural plant products from two native plants of Louisiana, that have been reported in the Native American ethnobotanical literature to have antifungal/antibacterial properties. An in-vitro bioassay experiment was conducted using the agar plug diffusion method testing the antifungal inhibition of crude ethanol extracts from the two species against each of the two pathogens Sclerotium rolfsii and Botrytis cinerea, on four plates each of Extract 1 Diospyros virginiana L. and Extract 2 Equisetum hymale L. of 1/4PDA spiked at a dose of 250ppm, 500ppm, 750ppm, and 1000ppm against a control plate of 1/4PDA for six days. Based on this initial crude extract bioassay there is a highly significant difference in the two crude extracts (p=0.000105) when tested against Botrytis cinerea. There is also a significant difference in concentration. The test against Sclerotium rolfsii did not find any significant inhibition from either of the plant extracts tested. From our findings we will continue the research study to test the antifungal potential of crude ethanol extract as well as Hexane, chloroform, ethyl acetate soluble fractions of Extract 1 Diospyros virginiana. The goal of the study is to integrate the antifungal compounds and their application for the development of best practices in Cannabis production.

Speakers

Jennifer Blanchard

Louisiana State University

Jennifer Blanchard is a botanist and Instructor of Horticulture in the School of Plant Environmental and Soil Sciences (SPESS) at LSU. She has created a new course at the university in Louisiana Medicinal Plants that focuses on the native indigenous plants of the state. She is also... Read More →

Wednesday September 25, 2024 2:15pm - 2:30pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

2:30pm HST

HEMP 2 - Investigating Fiber Hemp Seed Size Impact on Germination, Emergence, and Early Growth Rate

Wednesday September 25, 2024 2:30pm - 2:45pm HST

South Pacific 2

Fiber hemp (Cannabis sativa L.

Speakers

Samantha Carroll

Graduate Research Assistant, North Carolina State University

Co-authors

Amanda Cardoso

North Carolina State University

David Suchoff

North Carolina State University

Rong Yin

North Carolina State University

Wednesday September 25, 2024 2:30pm - 2:45pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

2:45pm HST

HEMP 2 - Modified Media and Lighting for Repeated In Vitro Cutting Cycles of Cannabis Sativa

Wednesday September 25, 2024 2:45pm - 3:00pm HST

South Pacific 2

Micropropagation usually involves cytokinin in single-harvest batches. We report two in vitro studies with multiple harvest: (1) fed batch process with modified physical states and (2) LED light treatments. In (1), genotypes of Cannabis sativa were observed in stationary agar (A), stationary Oasis® infused with liquid (OIL) and agitated Oasis® infused with liquid (AOIL).Fifteen explants were planted in vessels with 120 mL DKW medium harvested on 3-week cycles, with 0 or 15 mL additional media. Harvested shoots, length, and dry mass from repeated cycles were recorded. Genotypes T1 and Peach failed on multiple harvest cycles and were eliminated, although single cycle had higher quality in OIL. BaOx and Cherry1 on OIL/AOIL with additions were better quality than A in five cycles. Shoots harvested increased from 15 to 30 in cycles 1-3 in OIL/AOIL, but in A were approximately 20, while length was longest in OIL/AOIL. By cycle 3, all measured responses were decreasing until cycle 5 where a minimum of 7 shoots per vessel or more were only in OIL, but shoots were too short to plant in greenhouse. In (2), blue and supplemental far-red were observed with in vitro shoots of BaoX and Cherry1. OIL treatments were placed in LED polychromatic and dichromatic light (white, high red:blue, medium red:blue, white w/5% far-red, high red:blue 5% far-red, medium red:blue w/5% far-red, low red:blue w/ 5% far-red) at similar intensities (190-240 µmols·m-2·s-116 h-photoperiod). Media additions were made with responses recorded bi-weekly. Five randomly selected microcuttings per vessel rooted ex vitro on mist bench for 16 days. Over multi-cycles, plants treated with 5% far-red increased number and length, while plants under higher blue light increased dry mass. Shoot number increased to 28 in cycles 1-3 with far-red, and 18 without before decreasing to initial 15 during cycle 5. The accumulated shoots per vessel over 5-cycles (10-weeks) was 108 with far-red, and 84 without. Shoot length in far-red-treated plants increased from 19 - 25 mm in cycle 3 before decreasing to 10 mm in cycle 5. Plants without far-red had 10 – 15 mm length the entire experiment. Dry mass was highest during cycle 1 with blue light before decreasing 50% in cycle 3, where it remained until cycle 5. Sixty-eight percent of shoots rooted regardless of prior in vitro treatment. OIL with media addition allowed shoots to be harvested five cycles, while signaling response of far-red light allowed increased productivity and length.

Speakers

Molly McKay

Clemson University

Co-authors

Elizabeth Luscher

Curio Wellness

James Faust

Clemson University

Jeffrey Adelberg

Clemson University

Matt Taylor

Curio Wellness

Raghupathy Karthikeyan

Clemson University

Wednesday September 25, 2024 2:45pm - 3:00pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

3:00pm HST

HEMP 2 - Differential effects of macro- and micronutrients on secondary metabolite production in drug-type (medical) cannabis

Wednesday September 25, 2024 3:00pm - 3:15pm HST

South Pacific 2

The medical potential of cannabis (Cannabis sativa L.) is based on the complex chemical profile, comprising hundreds of secondary metabolites including cannabinoids, terpenoids and flavonoids. Cultivation conditions were demonstrated to affect plant development, function and production of secondary metabolites in cannabis. Understanding regulation of plant response to environmental conditions is key for development of optimal chemical profile for modern medicine. We have recently demonstrated sensitivity of the secondary metabolite profile in medical cannabis to mineral nutrition, with considerable responses to N, P, and K nutrition. Therefore, knowledge on the cannabis plant response to fertigation schemes is essential for the optimization of cultivation for production of high quality standardized material for the medical market, as well as for development of plant products containing specific desirable phytochemical profiles. In the talk, we will discuss our recent results concerning the potential of additional macronutrients and micronutrients to regulate plant development and the profile of active secondary metabolites in ‘drug-type’ medical cannabis. In pot experiments under controlled conditions, we demonstrated differential induction of changes in the cannabinoid and terpene profiles in ‘drug-type’ medical cannabis also by Ca, Mg, Zn and Mn. Furthermore, rate of uptake and deposition in the plants of individual macronutrients and micronutrients changes between the vegetative and the reproductive developmental stages, and along the reproductive phase.

Speakers

Nirit Bernstein

Institute of Soil Water and Environmental Sciences, ARO, Volcani Research Center

Wednesday September 25, 2024 3:00pm - 3:15pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

3:15pm HST

HEMP 2 - QTL mapping and gene discovery for seed traits in hemp (Cannabis sativa L.) F2 mapping populations

Wednesday September 25, 2024 3:15pm - 3:30pm HST

South Pacific 2

The emergence of a thriving hemp industry in the U.S. will depend on the breeding of high-yielding regionally adapted cultivars. Despite the latest research efforts, little is known regarding the genetic basis of important agronomic traits in hemp. The objective of this research was to identify and characterize genomic regions associated with seed morphology and quality traits. F 2 mapping populations were developed by crossing hemp germplasm bred or cultivated for cannabinoids (‘FL 58’ × ‘TJ’s CBD’), grain (GVA- H-20-1179 × ‘Picolo’), or fiber (‘Si-1’ × GVA-H-21-1003) market classes. These populations were investigated due to their variation in seed size and seed crude protein. The cannabinoid, grain, and fiber populations were grown and seed was harvested in 2021, 2022, and 2023, respectively. Harvested seeds were phenotyped for thousand seed weight (TSW) and crude protein content predicted by near-infrared (NIR) spectroscopy. The high-cannabinoid population was genotyped using an Illumina array, while the fiber and grain populations were genotyped using an Agilent SureSelect Custom Target Enrichment Probe Set. Marker-associated sequences were aligned to the CBDRx v.2.0 reference genome to align the physical and genetic maps. The TSW and protein content in the cannabinoid population ranged from 9.62 to 23.93 g and 19.25 to 31.89 %, respectively. In contrast, the TSW of the fiber and grain populations ranged from 7.34 to 45.17 g and 8.73 to 31.42 g, respectively. Numerous quantitative trait loci (QTL) of varying effect sizes were identified genome-wide. Notably, in the high- cannabinoid population, major and minor effect QTL for TSW were detected on Chr01 corresponding to 642 kb and 5.56 Mb genetic regions, respectively. Our results in the cannabinoid population highlight the importance of developing more than one F 2 mapping population in a given cross to capture the effect of more alleles due to high heterozygosity in hemp and evaluating distinct pedigrees to sample additional alleles in diverse genetic backgrounds. Narrowing the region around or identifying candidate genes will allow the development of high-throughput molecular markers for beneficial alleles across mapping pedigrees. These findings will accelerate hemp breeding programs through the implementation of marker-assisted selection for high-yielding and high-quality hemp cultivars for grain production.

Speakers

Luis Monserrate

Cornell University

Co-authors

Alexander Wares

Cornell University

Dustin Wilkerson

Cornell University

George Stack

Cornell University

Jacob Toth

Cornell University

Larry Smart

Cornell University

Lucia Vignale

Cornell University

Michael Quade

Cornell University

Wednesday September 25, 2024 3:15pm - 3:30pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

3:30pm HST

HEMP 2 - Dynamics of Cannabinoid Accumulation and Morphological Changes in Cannabis Inflorescences

Wednesday September 25, 2024 3:30pm - 3:45pm HST

South Pacific 2

Cannabis (Cannabis sativa L.) is cultivated for its cannabinoids, which have applications for therapeutic and recreational use. This phenomic evaluation explores accumulation of 16 cannabinoids of interest and associated morphological changes in Cannabis flowers. Eight cultivars of interest were grown in containers within an environmentally controlled greenhouse for 150 days (72 days reproductive). Light intensity, light duration, temperature, and relative humidity were regulated. Monitoring floral development, we observed a consistent increase in cannabinoid concentration as flowers matured, peaking in advanced stages of development. This accumulation pattern was consistent across diverse cultivars, which indicates this accumulation pattern to be the result of a fundamental biological mechanism. Concurrent with cannabinoid accumulation, we noted morphological changes in trichomes, which are widely utilized as markers of maturation within industry. Trichomes transitioned from sparse and translucent to abundant, enlarged, and displaying orange/amber hues as flowers matured, signifying floral maturation and trichome senescence. Importantly, a significant linear correlation emerged between cannabinoid accumulation and trichome morphological changes across all cultivars. This underscores a tight relationship between cannabinoid biosynthesis and trichome development, shaped by genetic factors. In summary, our findings demonstrate the intricate relationship between cannabinoid accumulation and floral morphology in Cannabis. Insights gained are invaluable for cultivar selection, breeding, and cultivation practices aimed at optimizing cannabinoid quantity and time to harvest. Understanding the underlying molecular mechanisms of cannabinoids promises tailored approaches for the optimization of cannabinoid production and the fostering of therapeutic and industrial advancements in Cannabis.

Speakers

Samuel Dotson

Louisiana State University

Co-authors

Babitha Jampala

Louisiana State University

Heather Kirk Ballard

SPESS

Heather Kirk-Ballard is an Assistant Professor and state extension specialist of Consumer Horticulture for the LSU AgCenter. She is the host of the Get It Growing ™ extension program focusing on home gardening that is disseminated weekly through video to news stations and in print... Read More →

Wednesday September 25, 2024 3:30pm - 3:45pm HST
South Pacific 2

Oral presentation (Individual talk), Hemp Research and Extension 2

SUBJECT Hemp

3:59pm HST

Ornamental Plant Breeding 2 (OPB 2)

Wednesday September 25, 2024 3:59pm - 5:00pm HST

South Pacific 2

QTL and Transcriptomic Analysis of Fragrance in the Auto-tetraploid Rose Population - Haramrit Gill
Assessing Micropropagation Traits in Anthurium Towards Breeding and Cultivar Development - Jaclyn Nicole Uy
Genotype Comparisons of Anthurium In Vitro Shoot Production in RITA® Bioreactors - Jacob Olarti
Treatment with Oryzalin Induces Chromosomal Changes in Salvia coccinea and Salvia splendens - John Ruter

Moderator

Teresita Amore

University of Hawaii

Wednesday September 25, 2024 3:59pm - 5:00pm HST
South Pacific 2

Oral Sessions, Ornamental Plant Breeding 2

SUBJECT Ornamental Plant Breeding

4:00pm HST

OPB 2 - QTL and Transcriptomic Analysis of Fragrance in the Auto-tetraploid Rose Population

Wednesday September 25, 2024 4:00pm - 4:15pm HST

South Pacific 2

For centuries, roses have been treasured for their therapeutic, cosmetic, and ornamental qualities. Among its many qualities, flower fragrance holds significant economic value. Over 400 volatile compounds contribute to the complex aroma of roses, with terpenoids, phenylpropanoids, and benzenoids playing dominant roles. Among these, geraniol, a monoterpene, contributes notably to the signature scent of rose oil. However, the fragrance of modern roses has gradually diminished as breeders have focused on enhancing other traits like appearance, adaptation, durability, and vase life. To gain a better molecular understanding of specialized metabolic pathways related to floral scent in roses we carried out QTL studies in the SWxBE autotetraploid rose population [Rosa L. ‘ORAfantanov’ (Stormy Weather™) x Rosa L. ‘Radbrite’ (Brite Eyes™)]. Our study suggests that the QTL for the fragrance was identified on chromosome 2 which colocalized with the genes involved with fragrance such as ODO1, EOBIII, and NUDIX. Two rose genotypes from the SWxBE population, ‘16401-N055’ (slightly fragrant) and ‘16089-N051’ (highly fragrant), were used for transcriptomic analysis. Gene expression analysis suggests that the monoterpenoid pathway was highly active in the highly fragrant rose with the NUDIX gene being highly expressed. Thus, NUDIX, a gene involved in geraniol biosynthesis, is a strong candidate gene for the QTL on chromosome 2. This study lays the groundwork for further exploration of the molecular pathways responsible for the scent of roses.

Speakers

Haramrit Gill

University of California, Davis

Co-authors

David Byrne

Texas A

Jeekin Lau

US Department of Agriculture

Oscar Riera-Lizarazu

Texas A

Wednesday September 25, 2024 4:00pm - 4:15pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamental Plant Breeding 2

SUBJECT Ornamental Plant Breeding

4:15pm HST

OPB 2 - Assessing Micropropagation Traits in Anthurium Towards Breeding and Cultivar Development

Wednesday September 25, 2024 4:15pm - 4:30pm HST

South Pacific 2

The major bottleneck in anthurium cultivar release is the availability of microprogated plants for field testing. Genotype has been a major consideration for anthurium protocol development. Different genotypes vary in in vitro performance even when using optimized media, therefore assessing proliferative variation under in vitro conditions could help identify cultivars that could introgress tissue culture traits and provide guidelines for future protocol development. The objective of this study is to assess the in vitro performance of different anthurium accessions from the University of Hawaii anthurium breeding program under the RITA® temporary immersion system and to observe how lineage affects in vitro performance. To evaluate shoot initiation/proliferation, 20 accessions of anthurium (parents, interspecific hybrids, complex hybrids, and wild relatives) were placed in RITA® supplemented with a liquid medium containing 0.3X MS salts with 0.2 mg/L BA, 15% coconut water and 20 g/L sucrose. Primary shoots were excised after 45 days to allow axillary buds to develop into secondary shoots. Bud masses (trimmed explant bases) were placed on a solid medium containing ½ MS salts with 15% coconut water, 20 g/L sucrose and 2g/L gellan gum to observe shoot proliferation and growth. Parameters were analyzed using mixed models with time block as random effects and accessions as fixed effects. Previously identified check cultivars (‘Marian Seefurth’ and ‘New Pahoa Red’) were used as controls in this study. Significant differences among the genotypes were observed in terms of the number of primary shoots, the number of secondary shoots, total axillary bud mass volume (cm3), number of explants with shoot, and number of explants with roots. Three selections and an accession were identified to have potential use for breeding. UH2053, UH2409, UH2327 and ‘New Pahoa Red’ showed superior or comparable number of primary and secondary shoots, explant volume, and rooting compared to the check cultivars. These lines will be considered as parents in future crosses for cultivar development. Cluster analysis was also performed and was cross-referenced to existing pedigree and breeding records. Our analysis revealed five clusters which indicate that that parentage influenced in vitro shoot production particularly in lines with Anthurium andraeanum, A. amnicola, A. formosum and A. kamemotoanum in their background. Pedigree and breeding records are valuable resources for predicting response profiles of anthurium in vitro performance.

Speakers

Jaclyn Nicole Uy

University of Hawaii

Co-authors

Jacob Olarti

University of Hawaii

Teresita Amore

University of Hawaii

Wednesday September 25, 2024 4:15pm - 4:30pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamental Plant Breeding 2

SUBJECT Ornamental Plant Breeding

4:30pm HST

OPB 2 - Genotype Comparisons of Anthurium In Vitro Shoot Production in RITA® Bioreactors

Wednesday September 25, 2024 4:30pm - 4:45pm HST

South Pacific 2

Anthuriums are Hawaii’s top cut flower with its sales valued at USD1.6 M in 2022. It is an important floriculture crop as it is both used as cut flower and foliage. Development of new genotypes allows the growers in Hawaii to produce new cultivars desired by the market. The University of Hawaii anthurium breeding program has identified new selections to field test with commercial growers. In order to do so, the breeding program propagates these selections to send to growers. Recently the use of bioreactors, such as RITA® on ‘New Pahoa Red’, resulted in three times more shoot production than in traditional flasks placed on a platform shaker. Shoot and root production and axillary bud mass volume of three new selections, UH2647, UH2651, and UH2652, were compared against the control ‘New Pahoa Red’. Ten nodes of each genotype were placed in a RITA® bioreactor, and replicated five times in a completely randomized design. Nodes were cultured in liquid medium consisting of 0.3MS, 0.1 mg l-1 BA, 15% coconut water, 20 g l-1 sucrose, and 1 ml l-1 NaSiO3. The plants were cultured in the bioreactors for 1.5 months, and then removed to obtain the number of shoots, roots, and axillary bud mass volume. Primary shoots were excised and transferred to 0.3 MS, 15% coconut water, 20 g l-1 sucrose, and solidified with 6 g l-1 Gelzan® to promote axillary bud growth and shoot development. The pH for all media was adjusted to 5.8. One month later, shoots (~0.5 cm in height) were excised from the axillary bud masses. Shoot counts excised after initial culture in the liquid medium and after placement in the shoot development solid medium were analyzed using one-way ANOVA on R studio. Axillary bud mass volume and root number were analyzed. UH2647 significantly produced more shoots than UH2652 and ‘New Pahoa Red’, while UH2651 was not different from any genotype. UH2647 also had the highest average axillary bud mass volume. UH2651 and UH2652 produced significantly more roots than the control. Knowing the genotypic differences in shoot production will assist propagation facilities in developing guidelines to schedule production of individual genotypes.

Speakers

Jacob Olarti

University of Hawaii

Co-authors

Jaclyn Nicole Uy

University of Hawaii at Manoa

Teresita Amore

University of Hawaii

Wednesday September 25, 2024 4:30pm - 4:45pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamental Plant Breeding 2

SUBJECT Ornamental Plant Breeding

4:45pm HST

OPB 2 - Treatment with Oryzalin Induces Chromosomal Changes in Salvia coccinea and Salvia splendens

Wednesday September 25, 2024 4:45pm - 5:00pm HST

South Pacific 2

Salvia coccinea (diploid) and Salvia splendens (tetraploid) and their associated cultivars are widely available, commercially profitable, and environmentally supportive flowering annuals. In recent years, exciting cultivars have been successfully introduced. This investigation explores further development of S. coccinea ‘Summer Jewel Lavender’, S. coccinea ‘Hummingbird Forest Fire’, and S. splendens ‘Mojave Red and White Bicolor’ through treatments by oryzalin for the potential development of novel cultivars. Surflan™ or oryzalin (4-(dipropylamino)-3,5-dinitrobenzenesulfonamide) and the nonionic surfactant SilEnergy™ were applied as a foliar spray for one, two, three, and six days to induce changes in chromosome numbers. Data collected included morphological observations, measurements of foliage and flowers, flower numbers, and ploidy analysis via a CytoFLEX™ flow cytometer. Ploidy changes were achieved in seedlings across all the treatment groups. Novel traits were identified, ranging from smaller overall growth habits and foliage, larger and increased numbers of flowers, and new floral pigmentation while maintaining vigor and potential for container production. Optimization of treatments will be discussed. The findings of this research have practical implications for plant breeders, landscape designers and architects, horticulturists, and environmental researchers as the market continues to demand drought-tolerant, low-growing, long-flowering, and pollinator-attracting plants.

Speakers

John Ruter

University of Georgia

Allan Armitage Endowed Professor of Horticulture and Director, Trial Gardens at UGA

Co-authors

William Martin

UGA

Wednesday September 25, 2024 4:45pm - 5:00pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamental Plant Breeding 2

SUBJECT Ornamental Plant Breeding

6:00pm HST

Graduate Student Poster Competition

Wednesday September 25, 2024 6:00pm - 7:00pm HST

South Pacific 2

This competition is open to graduate students that have a poster presentation scheduled during the ASHS conference AND have also signed up to participate in this competition (Note: This is separate of the assigned time to present your abstract during the conference program).

Please note that if you do not also present your poster during the regularly scheduled Poster session, you will be disqualified from the Poster Competition.

Competition participants will be assigned to a room to present for the competition (this information will be emailed to you the week prior to the conference). You will be responsible for bringing your poster on a thumb drive to your assigned room in order to participate.

Wednesday September 25, 2024 6:00pm - 7:00pm HST
South Pacific 2

Competitions, Student Activities

SUBJECT Competition

7:59am HST

Viticulture and Small Fruits 3 (VSF 3)

Thursday September 26, 2024 7:59am - 9:15am HST

South Pacific 2

Using Biochar As a Soil Amendment in Blueberry Production - Zilfina Rubio
Effects of Aged Pine Bark Amendments on Container-Grown Southern Highbush Blueberry Growth and Substrate Properties - Brandan Shur
Ground Covers Shape Canopy Microclimate And Fruit Quality Components In A Blueberry Orchard - Josh VanderWeide
Enhancing Blueberry Production with Photo-Selective Devices - Amit Godara
Modeling Production Curves of Southern Highbush Blueberry for Improved Productivity and Efficient Harvestability - J. Martin Zapien-Macias

Moderator

Zilfina Rubio

University of Georgia

Thursday September 26, 2024 7:59am - 9:15am HST
South Pacific 2

Oral Sessions, Viticulture and Small Fruits 3

SUBJECT Viticulture

8:00am HST

VSF 3 - Using Biochar As a Soil Amendment in Blueberry Production

Thursday September 26, 2024 8:00am - 8:15am HST

South Pacific 2

Biochar was tested as a possible soil amendment for blueberry production and compared with pine bark, which is commonly used as a soil amendment in blueberry production in the southeastern United States. Three treatments were established in sandy soil: biochar, pine bark (commercial standard), and control (non-amended soil) in which the variety ‘Farthing’ was planted. Soil characteristics were measured two months and 11 months after the incorporation of the amendments. Plant growth, and physiological traits were measured a year after planting. Biochar increased soil pH compared to pine bark and non-amended soil (control). Organic matter (OM) was higher in pine bark amended soil than in biochar. Biochar increased the Ca/Mg ratio 2 months after its incorporation and maintained P availability compared to the control and pine bark treatments. Eleven months after the incorporation of the amendments, the aluminum content was higher in the soil amended with biochar than in the control, whereas the Fe content was higher in the soil amended with pine bark than in the control. Manganese levels were lower in the pine bark-amended soil than in any other treatment. Plant growth and physiological responses were not affected by the incorporation of biochar as a soil amendment. However, plants established on the pine-bark amended soil had lower Soil Plant Analysis Development (SPAD), stomatal conductance, and maximum fluorescence than blueberry plants established on biochar or non-amended soil.

Speakers

Zilfina Rubio

University of Georgia

Co-authors

Natalia Espinoza

University of Georgia

Thursday September 26, 2024 8:00am - 8:15am HST
South Pacific 2

Oral presentation (Individual talk), Viticulture and Small Fruits 3

SUBJECT Viticulture

8:15am HST

VSF 3 - Effects of Aged Pine Bark Amendments on Container-Grown Southern Highbush Blueberry Growth and Substrate Properties

Thursday September 26, 2024 8:15am - 8:30am HST

South Pacific 2

Blueberry cultivation is rapidly expanding due to a dramatic increase in the consumption of the fruit. Soilless substrates have been viewed as a method to increase the production and geographic availability of this fruit. The identification of optimal and alternative substrates for the growth and development of the plants is needed to further guide a new and growing industry. The purpose of this study was to investigate the suitability of aped pine bark substrates amended with coconut coir or wood fiber substrates produced from Pinus taeda for container production of southern highbush blueberry (Vaccinium sp.). Plant linears of ‘Star’ blueberry were grown in 7.3-L pots filled with substrates consisting of coconut coir, aged pine bark, and hammermilled wood fiber. These were each amended at three rates (0%, 20%, 40%, 60%, 80%, and 100%). The plants were harvested at 0 days, 70 days, 140 days, and 365 days to assess their growth and development, measuring plant dry weight at each interval. Additionally, the substrate's physical properties, including particle size and air space, were measured during these four periods to determine the degradation and its influence on substrate quality over time. The findings of this study suggest that coconut coir usage can be reduced by using wood fiber or aged pine bark due to the positive effect on early vegetative blueberry growth.

Speakers

Brandan Shur

North Carolina State University

Co-authors

Brian Jackson

North Carolina State University

Thursday September 26, 2024 8:15am - 8:30am HST
South Pacific 2

Oral presentation (Individual talk), Viticulture and Small Fruits 3

SUBJECT Viticulture

8:30am HST

VSF 3 - Ground Covers Shape Canopy Microclimate And Fruit Quality Components In A Blueberry Orchard

Thursday September 26, 2024 8:30am - 8:45am HST

South Pacific 2

Fruit quality parameters are typically reported by growers and researchers as an average. However, for small fruits such as blueberries, berry-to-berry variability in texture and flavor also impacts the consumer eating experience. The objective of this project was to capture how the uniformity of fruit quality parameters varies by 1) cultivar, 2) berry maturity, and 3) exogenous phytohormone applications. From 2022-2023, analyses were conducted on individual blueberries from multiple studies carried out in commercial fields in Michigan. First, we compared the uniformity of berry mass, diameter, firmness, and total soluble solids (TSS) in six northern highbush blueberry cultivars: “Duke,’ ‘Bluecrop,’ ‘Draper,’ ‘Calypso,’ ‘Elliott,’ and ‘Aurora.’ The uniformity was highest/lowest for berry mass in 'Bluecrop'/'Calypso', firmness in 'Bluecrop’ /‘Aurora,’ and TSS in 'Bluecrop'/'Elliott'. Second, we evaluated how changes in berry maturity due to delayed harvest affected the uniformity of berry mass, diameter, firmness, TSS, pH, total acidity (TA), TSS/TA, and aroma volatile concentrations in: ‘Duke,’ ‘Draper,’ and ‘Calypso’. Delayed harvest did not alter the uniformity of berry mass or TSS, but increased the uniformity of TA and TSS/TA in all three cultivars. The implications of delayed harvest on the uniformity of consumer liking scores will also be discussed. Finally, we tested whether exogenous application of multiple phytohormones impacted the uniformity of berry mass, diameter, firmness, and TSS in ‘Bluecrop’ and ‘Elliott’. Abscisic acid improved the uniformity of berry mass in 'Elliott,' but not firmness or TSS. Meanwhile, jasmonates had a limited effect on the uniformity of fruit quality parameters in 'Bluecrop'. The relative importance of the "average" and "uniformity" of fruit quality parameters will be discussed. We conclude that “uniformity” is an important component of fruit quality in blueberry.

Speakers

Josh VanderWeide

Michigan State University

Co-authors

Rufus Isaacs

Michigan State University

Sheng-yang Li

Michigan State University

Steve Van Timmeren

Michigan State University

Thursday September 26, 2024 8:30am - 8:45am HST
South Pacific 2

Oral presentation (Individual talk), Viticulture and Small Fruits 3

SUBJECT Viticulture

8:45am HST

VSF 3 - Enhancing Blueberry Production with Photo-Selective Devices

Thursday September 26, 2024 8:45am - 9:00am HST

South Pacific 2

Blueberries rank among the top ten agricultural commodities in Georgia, contributing 2.45% to the state's GDP, with 27,000 acres across the state and a farm gate value of $449.4 million. Blueberry plants are exposed to elevated temperatures and intense solar radiation during the growing season. This research aimed to reduce adverse environmental effects by modifying the spectral distribution of sunlight. Our team examined the application of photoselective devices Opti-Gro and ChromaGro in blueberry production in Georgia. The research experiment was conducted at two locations (Alma and Rebecca, GA) using a randomized complete block design with four treatments: T1 (Opti-Gro), T2 (ChromaGro), T3 (a commercial grow tube), and T4 (control-unprotected plant), each replicated five times. Photoselective devices positively impacted plant height, yield, total soluble solids, anthocyanins, and titratable acidity. Plants under T1 and T2 also resulted in higher net photosynthesis and stomatal conductance. In summary, the use of photoselective devices presents a promising approach to improve blueberry production in Georgia.

Speakers

Amit Godara

The University of Georgia

Co-authors

Angelos Deltsidis

The University of Georgia

Zilfina Rubio Ames

The University of Georgia

Thursday September 26, 2024 8:45am - 9:00am HST
South Pacific 2

Oral presentation (Individual talk), Viticulture and Small Fruits 3

SUBJECT Viticulture

9:00am HST

VSF 3 - Modeling Production Curves of Southern Highbush Blueberry for Improved Productivity and Efficient Harvestability

Thursday September 26, 2024 9:00am - 9:15am HST

South Pacific 2

Agronomic crops have their yield potential assessed once per growing season at harvest time. In contrast, horticultural crops such as blueberries (Vaccinium spp.) require prolonged harvest periods, spanning 6 to 8 weeks of recurrent mechanical- or hand-picking. Collected data throughout the harvest period offer a comprehensive source of information to estimate production curves (cumulative harvest). These capture the yield dynamics of each cultivar under specific environmental conditions and treatments. For blueberry growers in Florida, desirable production curves should exhibit: 1) accumulation at the beginning of the harvest season (earliness), and 2) reduced harvest periods (concentration). This pattern is advantageous as it could significantly enhance productivity and profitability while simultaneously cutting down labor costs linked to harvest operations. Thus, pinpointing cultivars displaying these beneficial traits is paramount. In this study, we considered the Weibull distribution to model the production curves for each genotype-in-environment combination. Phenotypic and genomic information were combined for model calibration to predict the corresponding parameters of the distribution besides yield performance in a multi-trait framework. To our knowledge, there are no methods in the current literature that address the identification of cultivars that both ripen early and/or are suited for concentrated harvesting. In this study, we employ a novel analytical approach designed to fill this gap, aiming to systematically identify cultivars aligning with these ideal production characteristics.

Speakers

J. Martin Zapien-Macias

PhD Student, University of Florida

Co-authors

Diego Jarquin

University of Florida

Gerardo H. Nunez

University of Florida

Thursday September 26, 2024 9:00am - 9:15am HST
South Pacific 2

Oral presentation (Individual talk), Viticulture and Small Fruits 3

SUBJECT Viticulture

9:59am HST

Pomology 3 (POM 3)

Thursday September 26, 2024 9:59am - 11:45am HST

South Pacific 2

Seven-year Yield and Fruit Quality Comparison of Four Apple Cultivars Between Tall Spindle and Bi-axis Systems in Western New York - Brian Lawrence
After Avery: Apple Photosynthesis and Evidence of a Changing Environment. A Historical and Technical Evaluation - Curt Rom
The Biological Mechanism Behind Early and Late Apple Sports - Alexander Engelsma
Characterizing Unique Apple Selections for U-Pick Growers in the Midwest Using Descriptive Analysis, Consumer Liking Tests, and Phytochemical Analysis - Lydia Balogh
Selection and Patenting of New, Grower Friendly Apple Trees by the Maryland Tree Architecture Project - Chris Walsh
Effects and Interactions of Water Stress and Rootstock on Physiological Responses and Ambrosia Beetle Colonization of Apple Trees - Melissa Munoz
The Role of Photosynthesis in the Regulation of Early Fruit Growth of Apple - Bayleigh Roussel

Moderator

Melissa Munoz

NC State University

Thursday September 26, 2024 9:59am - 11:45am HST
South Pacific 2

Oral Sessions, Pomology 3

SUBJECT Pomology

10:00am HST

POM 3 - Seven-year Yield and Fruit Quality Comparison of Four Apple Cultivars Between Tall Spindle and Bi-axis Systems in Western New York

Thursday September 26, 2024 10:00am - 10:15am HST

South Pacific 2

Increasing orchard planting density has helped improve grower profits and yields but establishment costs can be high. It is believed that by using bi-axis trees the number of trees required during planting can be reduced while possibly improving yields and fruit quality. To test this possibility, an orchard of four cultivars (‘Brookfield Gala’, ‘Aztec Fuji’, ‘Honeycrisp’, and ‘Ruby Mac’) was established and trained to either Tall Spindle (TS) or Bi-axis (BA) at 1m x 4m spacing. After the third year of growth, all TS trees and half of BA trees were summer hedged, resulting in three systems to compare: 1) TS hedged; 2) BA hedged; and 3) BA non-hedged. Measurements of trunk cross sectional area (TSCA), phenology, yield, and fruit quality were recorded for seven years to calculate cumulative values. At the end of the study, TSCA was larger on TS trees compared to hedged or non-hedged BA trees across cultivars. Biennial bearing was lower with ‘Brookfield Gala’ and ‘Aztec Fuji’ compared to ‘Honeycrisp’ and ‘Ruby Mac’ and trended lower on hedged or non-hedged BA trees than TS trees. The hedged or non-hedged BA trees had higher cumulative yields compared to TS trees across cultivars. Fruit size was reduced on hedged or non-hedged BA trees compared to TS trees, but all three systems had similar fruit color, firmness, and soluble solids on average. After seven years, there was no obvious benefit of using hedged or non-hedged BA systems to improve fruit quality, but higher yield from BA trees over TS trees when planted at the same density, regardless of hedging during the summer, was achieved. We calculated that BA trees could be planted at 15% lower planting density than TS trees to achieve the same yield.

Speakers

Brian Lawrence

Cornell University

Co-authors

Luis Gonzalez

IRTA

Terence Robinson

Cornell University

Thursday September 26, 2024 10:00am - 10:15am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

10:15am HST

POM 3 - After Avery: Apple Photosynthesis and Evidence of a Changing Environment. A Historical and Technical Evaluation

Thursday September 26, 2024 10:15am - 10:30am HST

South Pacific 2

In 1977 Avery published a review of apple leaf photosynthesis (Pn) rates to estimate maximum rates with current technologies and conditions. This presents a recent review of more than 90 published reports of apple photosynthesis from 1978-2022 evaluated the techniques and equipment used, the experimental parameters of CO2, temperature, light, and vapor pressure deficit. The goal of the review was to determine if techniques used reflected changes in global atmospheric [CO2], and if there was evidence of response of apple leaves to changing [CO2] with time. Avery in 1977 estimated mean apple Pn rate to be ca. 14 µgCO2m-2s-1 and a maximum rate of ca. 22 µgCO2m-2s-1. The current review suggests an estimated mean apple Pn rate to be ca. 15.6 µgCO2m-2s-1 , similar to Avery, but a maximum rate of ca. 31-35 µgCO2m-2s-1, higher than Avery. Since 1977, there has been an approximately 26% increase in global CO2. There was no correlation between experimental [CO2] or atmospheric [CO2] and reported Pn, and although reported Pn rates tended to increase with time, there was no significant correlation to time. Experimental[CO2] was reported in 58% of the reports but omitted in others. Experimental parameters of measurement temperature or vapor pressure deficit were commonly not reported.

Speakers

Curt Rom

Thursday September 26, 2024 10:15am - 10:30am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

10:30am HST

POM 3 - The Biological Mechanism Behind Early and Late Apple Sports

Thursday September 26, 2024 10:30am - 10:45am HST

South Pacific 2

Somatic mutations in apple commonly develop into viable bud sports for cultivation. When an apple bud sport has a desirable attribute such as improved color, size, shape, flavor, firmness, sweetness, or harvest timing, it has potential to be introduced as a new cultivar that growers utilize, and consumers enjoy. The genetic mutations and related mechanisms associated with early or delayed maturation (respectively resulting in early or late harvest date) in apple sports are not known despite their value to the industry. By acquiring knowledge about these genetic mutations and their respective molecular mechanisms, breeders can identify markers to conduct more informed crosses to select for early or late maturing apple lines. Apple lines with differing developmental rates resulting in differing ‘designed’ harvest windows would optimize the deployment of field laborers for the apple harvest and improve use of cultural practices to influence harvest time. Comparison of physiology-based markers of fruit developmental stages for apple sports with different maturation dates has been done, but, to the author’s knowledge, not on trees for which crop load has been appropriately adjusted to eliminate its effect on developmental rate. In this study, crop load was regulated on 6 different apple cultivars according to tree trunk cross-sectional area. The sports selected were the ‘Gala’ sport ‘Autumn Gala’ also known as ‘Harry Black’, the early maturing ‘Fuji’ sport ‘September Wonder Fuji’, and the early maturing ‘Cripps Pink’ (‘Pink Lady®’) sport ‘Maslin Cripps Pink’. These three sports were compared to their progenitor/standard harvest time cultivar. Apple fruits were measured on each of five trees per cultivar, and volumetric growth rate was analyzed. We found that in each comparison, fruit growth rate of the early variant was significantly greater early in fruit development, roughly coinciding with the expected conclusion of the cell division phase based on phenology. Consequently, a narrower window of genetic events responsible for the early or late harvest timing phenotype has been captured. Our work confines the search for genetic events responsible for the harvest date mutations to the early developmental stages for apple fruit. We propose that harvest date in these apple bud sports is physiologically predetermined from the very early stages of fruit development and very likely not a function of strictly ripening-related processes.

Speakers

Alexander Engelsma

Michigan State University

Co-authors

Berkley Walker

Michigan State University

Courtney Hollender

Michigan State University

Mauricio Tejera-Nieves

Michigan State University

Randolph Beaudry

Michigan State University

Thursday September 26, 2024 10:30am - 10:45am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

10:45am HST

POM 3 - Characterizing Unique Apple Selections for U-Pick Growers in the Midwest Using Descriptive Analysis, Consumer Liking Tests, and Phytochemical Analysis

Thursday September 26, 2024 10:45am - 11:00am HST

South Pacific 2

The apple U-Pick market in Ohio lacks diversity in varieties to meet consumer demand outside of those typically available at grocery stores. Apple growers want new cultivars that are suited for growth in the Midwest, ripen across the picking season, and intrigue customers with unique flavors, textures, and traits. These diverse and unique tasting apples exist, but it is difficult to market these apples without a comprehensive understanding of the traits and consumer desirability of these fruits. This project aims to identify and characterize sensory traits in 33 up-and-coming apple selections including commercial, in-development, and wild varieties with novel characteristics suited for local production. Apple selections were chosen in conjunction with apple specialists at The Ohio State University and local apple growers. Consumer perception and apple traits were evaluated through two sets of sensory experiments: consumer hedonic testing and descriptive analysis. Consumer testing was conducted in private sensory booths, where apple slices were provided in a randomized, blinded order to mitigate order effects. One hundred participants rated apples on their appearance, texture, flavor, and overall liking on a 9-pt hedonic liking scale (i.e., dislike extremely to like extremely). Descriptive analysis was conducted by 12 trained panelists who used references as anchors on a 10-pt scale to score important appearance, aroma, flavor, and texture fruit characteristics. Measured characteristics were decided in collaboration with the panel organizer, trained panelists, and included traits of particular interest to growers. The trained panelists rated 26 traits like red color, floral notes, sweetness, and crispness. Anchors were carefully selected to provide precise references along the scale, such as sucrose solutions of varying concentration to calibrate judgements of sweetness. To compare how different factors of the apple related to each other, correlation analyses were run on the datasets. Flavor liking had the strongest positive correlation with overall liking, followed by texture liking, while appearance liking showed a weaker positive correlation. Sweetness exhibited a slight positive correlation with overall liking, whereas sourness showed the opposite. Using mean separation tests, we identified 15 apple selections liked equivalently to Honeycrisp, a top commercial apple. Further phytochemical analysis will enable gaining insights on nutritional quality profile and its relation to consumer preference. Our goal is to provide information on novel apples that will enable apple growers to diversify their offerings, which will also benefit producers and consumers.

Speakers

Lydia Balogh

PhD Student, The Ohio State University

Co-authors

Christopher Simons

The Ohio State University

Diane Miller

The Ohio State University

Jessica Cooperstone

The Ohio State University

Jonathan Fresnedo Ramirez

The Ohio State University

Thursday September 26, 2024 10:45am - 11:00am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

11:00am HST

POM 3 - Selection and Patenting of New, Grower Friendly Apple Trees by the Maryland Tree Architecture Project

Thursday September 26, 2024 11:00am - 11:15am HST

South Pacific 2

The Maryland Tree Architecture Project (MD-TAP) used classical plant breeding methods to create, identify, select and then patent grower-friendly apple trees. The project began in 1991 with the open pollination of 'McIntosh Wijcik' trees set in an isolated 'Gala' block. Elite seedlings resulting from that initial cross then served as male parents in an open-pollination of commercial cultivars well-adapted to the warm, wet, windy, Mid-Atlantic climate. Two scion-dwarfed, apple trees producing good quality fruit and demonstrating a reduced susceptibility to fire blight resulted from this effort. These two selections were patented as 'MD-TAP1' and 'MD-TAP2' in 2023. A replicated field trial was set in 2016 to compare these two scion-dwarfed selections, with their wild-type siblings also from this program. Trees were budded onto 'M.111,' a semi-dwarfing rootstock to assess their growth habit and tree size without the benefit of trellis support or sustained annual pruning. Trees were set at a 2.75 by 4.25 m (9 by 14 ft) spacing and are still manageable. Despite annual pruning, they are similar in height to trees in an adjacent tall-spindle planting budded onto dwarfing rootstocks. The University of Maryland concluded two Materials Transfer Agreements (MTAs) with other universities before the patents were allowed. After patenting, the University began contacting commercial nurseries in the Mid-Atlantic Region for future testing and licensing.

Speakers

Chris Walsh

University of Maryland

Chris Walsh is a Professor Emeritus in Horticulture. He currently maintains research and educational programs in tree fruit production and apple tree breeding, and in fresh-market produce safety.

Thursday September 26, 2024 11:00am - 11:15am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

11:15am HST

POM 3 - Effects and Interactions of Water Stress and Rootstock on Physiological Responses and Ambrosia Beetle Colonization of Apple Trees

Thursday September 26, 2024 11:15am - 11:30am HST

South Pacific 2

Rapid apple decline (RAD), a phenomenon that causes sudden decline and death of young apple trees in high-density orchards, is a pressing issue. This problem has been associated with abiotic (flood, drought, freeze) and biotic stressors (fungi, bacteria, and insects). Ambrosia beetles (AB) (Xylosandrus spp.) have been linked to stressed trees suffering from RAD. However, the direct association is still not clear. We evaluated the effects and interactions of rootstock (‘B. 9’, ‘M. 7’, and ‘G. 41’) and water stress (flood, drought, control) on physiological responses and AB colonization. Specifically, a greenhouse experiment was performed in spring 2023 on 14-month-old potted ‘MAIA1’ trees. Trees were subjected to water stress for 20 d. Water stress treatments consisted of a saturated pot-in-pot system for flood, water with-held for the duration of the experiment for drought, and irrigation based on soil moisture, maintaining the pots between 0.7 and 1 water fraction volume for control trees. The experiment had a randomized complete block design, was replicated 10 times, and had a factorial treatment structure. Measurements were made every 2 d for soil moisture, fluorometry, and spectrometry data, every 4 d for leaf gas exchange and midday water potential, at 7 and 14 d for ethanol volatiles, and at the termination of the experiment for AB colonization. Under control conditions, ‘G. 41’ trees had higher transpiration, stomatal conductance, and assimilation rates than ‘B. 9’ and ‘M.7’ trees. However, after 4 d of stress, ‘G. 41’ showed a more rapid decline in leaf gas exchange parameters relative to other rootstocks. Drought-stress trees from the three rootstocks declined 4 d faster than flood trees during the first 12 d. However, this decline occurs more abruptly in ‘G. 41’ and ‘M. 7’ trees. From 16 to 20 d, drought and flooded trees have a similar response. Under control conditions, all three rootstocks have similar quantum efficiency values. Conversely, under water stress, ‘G. 41’ and ‘M. 7’ declined faster than ‘B. 9’ trees, with a more severe response to drought for ‘G. 41’ and ‘M. 7’ trees. Chlorophyll index (Ci) showed lower values for flood and drought trees after 10 d for ‘G. 41’ and ‘M. 7’ trees. For ‘B. 9’, this was only true in drought trees. Flooded trees had AB tunnels three times longer than control, and drought trees were the only ones where AB larvae were observed, which was linked to higher ethanol levels.

Speakers

Melissa Munoz

NC State University

Co-authors

Christopher Ranger

USDA-Agricultural Research Service

Thomas M. Kon

NC State University

Thursday September 26, 2024 11:15am - 11:30am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

11:30am HST

POM 3 - The Role of Photosynthesis in the Regulation of Early Fruit Growth of Apple

Thursday September 26, 2024 11:30am - 11:45am HST

South Pacific 2

Photosynthesis is well-known to not only occur in leaves but also other tissues like stems, sepals, and fruits. Fruit photosynthesis has been documented in cucumber, tomatoes, satsuma mandarins, prickly pear, wheat, and apple. Fruit photosynthesis occurs in these instances not only to contribute to carbon assimilation but to support other metabolic processes, the synthesis of metabolites, and seed development. Early fruit growth in apple is regulated by energy-intensive cell division that lasts for approximately five weeks before switching to a phase of predominantly cell expansion-driven growth. Thus, fruit photosynthesis during early fruit development in apple could function to fulfill the resource and energy requirements necessary for the growth and development of fruit tissues. To examine this potential contribution of photosynthesis to apple fruit metabolism, shade bags made of 30%, 65%, and 80% shade cloth were placed on fruitlets at 16 days after full bloom. The effects of fruit shading on fruit tissue plastid ultrastructure, metabolite composition and tissue transcriptomes were analyzed. Using transmission electron microscopy (TEM), we found that plastids in the peel and cortex overall resembled that of photosynthetically active plastids; they contained stromal and granal thylakoids similar to those found in leaves. Spatially, pith plastids displayed unique hypergranal features , with increased granal thylakoids and a significantly reduced presence of stromal thylakoids. When compared to the control, 80% shaded peel plastids contained more plastoglobuli, and 80% shaded pith plastids displayed prolamellar bodies, which are indicative of disassembly. Further, significantly lower chlorophyll a concentration was observed in shaded fruit. Metabolite analyses indicated that sorbitol was significantly greater in shaded fruit than in the control. Transcriptome analyses indicated substantial changes associated with carbohydrate metabolism in the fruit cortex and peel in response to fruit shading. Together, these analyses indicate a significant contribution of fruit photosynthesis to early fruit growth and development in apple.

Speakers

Bayleigh Roussel

University of Georgia

Thursday September 26, 2024 11:30am - 11:45am HST
South Pacific 2

Oral presentation (Individual talk), Pomology 3

SUBJECT Pomology

11:59am HST

Weed Control and Pest Management 2 (WCPM 2)

Thursday September 26, 2024 11:59am - 1:40pm HST

South Pacific 2

Evaluating Bacterial Diversity and Pest Control Efficacy of Steam Disinfestation Treatments in the Salinas Valley Spinach and Lettuce Fields - Erika Escalona
Development of Minirhizotron for Nondestructive Rapid Detection of Parasitic Nematodes - Tim Pannkuk
Genome Sequencing of Crapemyrtle Bark Scale for Developing Advanced IPM Strategies - Bin Wu
A New Technique for Visual and Quantitative Assessment of Pesticide Applications to Tree Trunks for Control of Trunk-boring Insects - Amy Fulcher
Factors Affecting Spray Coverage on Red Maple Trunks from an Air-Assisted Sprayer - Amy Fulcher
Rice Hull Use in Container Production; Economics and Efficacy - Shawn Steed
Organic and Synthetic Herbicides for Controlling Liverwort Growth in Containerized Ornamental Production - Manjot Sidhu
Impact of Changing Climate on Weed Control in Ornamental Crop Production: A Potential Research Area - Supti Saha Mou
Development of “EZA”, a New Pesticide Suitable for Organic Production of Horticultural Crops - Merci Uwimbabazi
Impact of Partial Saltwater Agroecosystems on Weed Competition in Watermelon. - Joseph Bazzle

Moderator

Shawn Steed

University of Florida

Thursday September 26, 2024 11:59am - 1:40pm HST
South Pacific 2

Poster Session, Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:00pm HST

WCPM 2 - Evaluating Bacterial Diversity and Pest Control Efficacy of Steam Disinfestation Treatments in the Salinas Valley Spinach and Lettuce Fields

Thursday September 26, 2024 12:00pm - 12:10pm HST

South Pacific 2

As the specter of climate change looms larger, sustainable and environmentally friendly alternatives for pest and pathogen control in agriculture are becoming increasingly imperative. Steam disinfestation, once an antiquated method overshadowed by chemical pesticides, is experiencing a resurgence due to heightened environmental concerns. Despite its historical use, there has been limited exploration of scaling up steam disinfestation for field applications in vegetable crops. Therefore, there is a central focus in this project to evaluate the efficacy of band steaming for disinfestation in spinach and lettuce fields in the Salinas Valley. This study seeks to advance the validation of banded steaming as a practical alternative to chemical fumigation by conducting a comprehensive assessment of vegetable productivity in lettuce grown in steamed soils versus non-steamed soils. The experiment utilized a custom-built steam applicator equipped with a low-pressure 1,000 kg/hour steam generator in Salinas, CA, during 2023. All research and trials were conducted at the Salinas Extension and USDA Center. In addition to evaluating efficacy of steam disinfestation for pest control, a preliminary evaluation of its impact on the soil microbiome was conducted on spinach and lettuce fields. Soil samples were collected before and after steam application, and crops were meticulously monitored for soil-borne disease and weed control, alongside yields at harvest. Preliminary results indicate effective weed control and lower pathogen pressure after steam treatments. Furthermore, the trials conducted from July 2023 to September 2023, involved verifying the performance of the steam applicator treatments, and assessing beneficial soil organisms using 16S sequencing in the spinach and lettuce fields. Through a thorough analysis of the outcomes derived from these trials, our objective is to offer in-depth insights into the overall efficacy of steam disinfestation and its potential implications for agricultural practices. This investigation is particularly focused on assessing its impact on the soil microbiome, the presence of pathogens, and its effectiveness in weed control.

Speakers

Erika Escalona

graduate student, UC Davis

Co-authors

Steve Fennimore

UC Davis

Thursday September 26, 2024 12:00pm - 12:10pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:10pm HST

WCPM 2 - Development of Minirhizotron for Nondestructive Rapid Detection of Parasitic Nematodes

Thursday September 26, 2024 12:10pm - 12:20pm HST

South Pacific 2

Plant-parasitic nematodes are a historic problem in a wide range of horticultural and agronomic production conditions. Many horticultural crops can be negatively impacted during production since near-ideal environmental conditions are created for nematode growth and reproduction. Once established in the soil of a nursery, orchard, or greenhouse, there is also potential to spread the plant damaging nematodes via machinery, handheld equipment, soil movement, or footwear. Nematode presence may be detected by root visual symptoms of infected plants, but laboratory nematode assays are a more reliable diagnostic tool – however costly and time consuming. Our team developed a portable handheld infrared thermography-minirhizotron device for rapid, nondestructive detection of the presence or absence of plant parasitic nematodes. This self-contained device, using infrared thermography, processes images using an algorithm. It can be operated by trained personnel to perform on-site rapid diagnosis in a nursery environment. A prototype has been constructed and tested in laboratory setting. It is equipped with wireless communication and network capabilities, allowing remote access and control. The goal is to develop a smart device that can be scaled up and networked for early detection and rapid response to a wide range of soil nematodes of horticultural importance. The algorithm is developed to distinguish between root-knot and cyst nematodes in infected plants.

Speakers

Tim Pannkuk

Sam Houston State University

Co-authors

Autumn Smith-Herron

Sam Houston State University

Faruk Yildiz

Sam Houston State University

Junken Ma

Sam Houston State University

Recayi Pecen

Sam Houston State University

Thursday September 26, 2024 12:10pm - 12:20pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:20pm HST

WCPM 2 - Genome Sequencing of Crapemyrtle Bark Scale for Developing Advanced IPM Strategies

Thursday September 26, 2024 12:20pm - 12:30pm HST

South Pacific 2

Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae), an invasive insect pest threatening horticultural industries, has spurred the search for sustainable control methods. Our recent research focused on two key aspects of CMBS behavior: feeding and mating. In feeding, our studies revealed that while nicotine does not affect the phloem salivation process in CMBS, it significantly impairs the insect’s ability to ingest phloem sap, suggesting that nicotine interferes with the precise muscular coordination in the acephalothoracia region of CMBS, thereby offering a potential mechanism for chemical control. By identifying the genes that encode nicotinic receptors, we can pinpoint potential chemical targets to disrupt CMBS feeding behavior. In studying mating behavior, we found that mating is crucial for CMBS reproduction. Solid-phase micro-extraction and GC/MS assays revealed that CMBS release unique volatile compounds at different life stages. By identifying the genes responsible for sex pheromone production and pheromone receptors, our research lays the groundwork for developing pheromone-based traps and mating disruption strategies. Moreover, the discovery of juvenile hormone receptors and their expression at various developmental stages suggests additional opportunities to hinder CMBS growth and reproduction. We are conducting a comprehensive genomic analysis of CMBS using PacBio SMRT, Hi-C, and Illumina genome sequencing. This genomic framework will be used to develop innovative pest control strategies to control CMBS populations while supporting integrated pest management (IPM) techniques and reducing environmental impact.

Speakers

Bin Wu

Texas A

My integrated research and Extension programs focus on the evaluation, selection, and breeding of horticutlural specialty crops, as well as the study of insect-plant interactions and natural enemies. The goal is to develop integrated pest management (IPM) strategies for controlling... Read More →

Co-authors

Hongmin Qin

Texas A

Hui Duan

USDA

Margaret Pooler

Floral and Nursery Plants Research Unit, U.S. National Arboretum, U.S. Department of Agriculture-Agricultural Research Service

Thursday September 26, 2024 12:20pm - 12:30pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:30pm HST

WCPM 2 - A New Technique for Visual and Quantitative Assessment of Pesticide Applications to Tree Trunks for Control of Trunk-boring Insects

Thursday September 26, 2024 12:30pm - 12:40pm HST

South Pacific 2

Water sensitive paper (WSP), a yellow paper that stains blue in the presence of water, can be used to evaluate spray characteristics. While traditionally used as 2x3-inch cards placed in the canopy, we developed a WSP wrap that can be wrapped around a trunk, sprayed, and removed without damaging the trunk to assess spray distribution for control of trunk-boring insects. Trunk wraps are made by adhering a 1x8.5-inch strip of WSP to a 1.75x8.5-inch strip from a printable vinyl sticker sheet. To install, the adhesive is exposed, the wrap is manually wrapped around the trunk, and pressure is applied by gripping the wrapped portion of the trunk. However, the tapered shape, bumpy surface, and small trunk caliper, as well as humidity can cause wraps to unravel during experiments. In preliminary tests, 50% of uncoiled, i.e., flat, 4.25-inch wraps unraveled from 16.5 mm caliper Acer rubrum ‘Franksred’ Red Sunset® red maple trunks. Our objective was to test if pre-coiling wraps prevented unraveling. We tested four treatments with five replications each: 1. 8.5-inch wraps coiled and stored in 2-inch diameter PVC, 2. 8.5-inch uncoiled wraps, 3. 4.25-inch wraps coiled and stored in 0.75-inch PVC, and 4. 4.25-inch wraps coiled in 0.75-inch PVC and stored in 1-inch PVC. After 2 weeks of storage, we installed wraps on 16.5 mm caliper Red Sunset® trunks. After 5-10 minutes, we reapplied pressure to both 8.5-inch wraps and 4.25-inch flat wraps because they unraveled, our standard practice; both 4.25-inch pre-coiled wrap treatments remained tightly wrapped and did not require this step. After an additional 5-10 minutes we assessed whether or not wraps were tightly wrapped around trunks. All wraps within both 4.25-inch pre-coiled wrap treatments remained tightly wrapped around trunks. All 8.5-inch uncoiled wraps unraveled and 40% of 8.5-inch pre-coiled wraps unraveled suggesting a modest benefit to coiling this length and that extra length is not beneficial. Following this experiment, we successfully used pre-coiled 4.25-inch wraps on 16-19 mm caliper maple and 8.5-inch wraps on 46-52 mm caliper oak tree trunks. We observed that repeated wrap installation (approx. ≥5 times) to the same location on the same day sometimes caused minor bark damage. Pre-coiled wraps of the correct length unraveled in the high humidity of day-time field experiments but remained tightly wrapped in evening trials under less humid conditions. To maintain the coil during storage, we protected wraps with paper, then secured them with a rubber band.

Speakers

Amy Fulcher

University of Tennessee

Co-authors

Karl McKim

The University of Tennessee

Laura Whaley

University of Tennessee

Lauren Fessler

University of Tennessee

Lily Slade

University of Tennessee

Thursday September 26, 2024 12:30pm - 12:40pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:40pm HST

WCPM 2 - Factors Affecting Spray Coverage on Red Maple Trunks from an Air-Assisted Sprayer

Thursday September 26, 2024 12:40pm - 12:50pm HST

South Pacific 2

Trunk-boring pests are a significant threat to nursery crops. Despite the prominence of air-assisted sprayers, little research has been published about their coverage of tree trunks. We assessed spray characteristics of a Jacto A400/850 sprayer with the objective of determining the lowest spray rate that provided at or near 100% trunk coverage. Water sensitive paper (WSP) was wrapped around the trunks at two heights in an external row and the middle row of a 3-row block of red maples (Acer rubrum) to assess coverage. Assessments included 15 trials with application rates from 65 to 244 GPA at 1.5 and 2.5 mph tractor speeds. Travel Speed: Spraying at 108 GPA and 112 GPA achieved ≥95% coverage when traveling 1.5 mph with windspeeds less than 1.5 mph. Spraying 112 GPA at 1.5 mph provided 96% coverage on wraps at both heights despite a maximum (unsustained) windspeed of 3.9 mph. Increasing the travel speed to 2.5 mph reduced the spray rate to 68 GPA and coverage to 79%. Spraying 244 GPA when traveling 1.5 mph provided 95% coverage. Increasing the travel speed to 2.5 mph decreased the rate to 146 GPA, and yielded coverage of 97%. Spraying 146-224 GPA with 1.0 mph average windspeed or less yielded ≥95% coverage in all four trials. Wind Speed: When traveling 1.5 mph and spraying 108 GPA with an average windspeed of 1.3 mph, 96% coverage was achieved. Coverage was reduced to 88% when the average windspeed increased to 2.5 mph. Stakes: Trees were secured using 1-inch stakes installed 3 inches from the western face of each trunk. The western face of wraps at 9 of 12 locations had coverage equal to or greater than that of the total wrap in three trials with less than 1.3 mph average windspeed. Row: In 10 trials, there was ≤2.5% difference in coverage between external and middle rows. However, in 5 trials the middle row had greater coverage by at least 6%. Spraying 109-112 GPA can provide near complete trunk coverage under low wind speeds. Higher spray rates can overcome high wind and travel speed, but are undesirable given the potential for drift and waste. Neither presence of a stake nor middle row position equates to worse coverage. Trees in the middle row may benefit from being equidistant from the sprayer as it travels down both driveways. These results provide a framework for future trunk coverage tests utilizing variable-rate technology.

Speakers

Amy Fulcher

University of Tennessee

Co-authors

Benjamin Lockwood

University of Tennessee

Cody Fust

Auburn University

Heping Zhu

USDA-ARS

Karl McKim

The University of Tennessee

Laura Whaley

University of Tennessee

Lily Slade

University of Tennessee

Thursday September 26, 2024 12:40pm - 12:50pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

12:50pm HST

WCPM 2 - Rice Hull Use in Container Production; Economics and Efficacy

Thursday September 26, 2024 12:50pm - 1:00pm HST

South Pacific 2

Weed control in woody ornamental container production is one of the most expensive inputs in production. Preemergent herbicides, mulches and hand labor are all methods of delaying, impeding, or removing weeds that will negatively impact the growth and aesthetics of the produced container plant. One method gaining popularity in Central Florida to reduce weed competition is the use of rice hulls (RH) as a mulch. Effective mulches will reduce the amount of weed competition plants face. Rice hulls are a byproduct from the rice industry and deemed a disposed waste. RH are applied by hand in a layer of about 0.5 to 1 inch deep and dry out in a relatively quick manner. Growers anticipate that RH reduce the costs of weed competition and hand labor from weeding operations. This research investigated the economic cost of RH and benefit of RH mulch in terms of weed growth reduction.

Speakers

Shawn Steed

University of Florida

Thursday September 26, 2024 12:50pm - 1:00pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

1:00pm HST

WCPM 2 - Organic and Synthetic Herbicides for Controlling Liverwort Growth in Containerized Ornamental Production

Thursday September 26, 2024 1:00pm - 1:10pm HST

South Pacific 2

Liverwort (Marchantia polymorpha L.) is a nonvascular, chlorophyll-containing, primitive, spore-bearing bryophyte. It is one of the major weed problems in container nurseries and greenhouse operations as it competes with the ornamental plant for resources within the container. Application of herbicides is a major component of any weed control program in ornamental production systems. There are limited herbicides labeled for liverwort control in greenhouse container production. A greenhouse experiment was conducted to evaluate the effect of various organic and synthetic herbicides on controlling liverwort growth. The herbicides were applied to nursery containers filled with standard substrate and amended with controlled release fertilizer for assessing the post-emergent liverwort control. Organic products namely Avenger, Scythe and WeedPharm were applied at 1X and 2X rates. Synthetic herbicides – Glyphosate, 2,4-D and Indaziflam were applied at 1X, 2X and 3X rates. Control set without any herbicide application was included as well. Percent of substrate surface covered by liverwort thalli was visually estimated bi-weekly until 16 weeks after first treatment. Fresh biomass of the thalli in each pot were also recorded at the end of the experiment. The experiment had six replications per treatment, and they were arranged in a randomized complete block design. For both the synthetic and organic herbicides, there was significant interaction between the type and rate of herbicide applied. The herbicide treatments were significantly different amongst each other and from the control. Out of various organic herbicides applied, all the herbicide treatments were able to limit liverwort coverage under 30% as compared to control (98%). WeedPharm and Scythe application at 2X and Avenger application at 1X rates recorded minimum liverwort fresh biomass. In the synthetic herbicide treatments, Indaziflam at 2X and 3X rates had minimal liverwort coverage and fresh biomass at the end of the experiment. Hence, these organic and synthetic herbicides can be a promising component for an integrated liverwort control program in containerized ornamental production.

Speakers

Manjot Sidhu

Michigan State University

Co-authors

Debalina Saha

Michigan State University

Thursday September 26, 2024 1:00pm - 1:10pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

1:10pm HST

WCPM 2 - Impact of Changing Climate on Weed Control in Ornamental Crop Production: A Potential Research Area

Thursday September 26, 2024 1:10pm - 1:20pm HST

South Pacific 2

The ornamental crop industry is a billion-dollar industry in the United States. Controlling weeds is a big challenge, as they can compete with ornamentals for soil, nutrients, water, light, and space by affecting the desired quality of ornamental crops like leaf and flower quality and color as well as proper growth. Weeds can also harbor insects, pests, diseases, and pathogens resulting in further reduction of market value. Due to greater genetic diversity and physiological plasticity, weeds are more likely to be able to adapt to a changing environment or climate. Increased atmospheric carbon dioxide (CO2) level can cause fertilization effect in C3 plants resulting in higher growth rates. Conversely, C4 plants are less likely to exhibit increased growth responses to elevated CO2 levels, as carbon dioxide fixation becomes saturated for them at around 360 ppm. So, ornamentals could gain a competitive advantage over many of the major weed species under elevated CO2, as many of the world’s ornamental crop species are C3 plants and many of the major weed species are C4 plants. But in reality, the scenario is different because other factors such as changes in herbicide efficacy and the ability of weed species to out compete ornamental species may come into play and limit this advantage. Plants that are grown in CO2-enriched environments often develop high concentrations of starch in leaves and greater total leaf area and biomass which can cause a dilution effect on herbicides. Additionally, C3 plants have been shown to have decreased stomatal conductance and increased leaf thickness in elevated CO2 which may also limit foliar uptake of herbicides. Environmental factors such as temperature, precipitation and relative humidity influence the efficacy of herbicides. There are studies that have reported decreased herbicide efficacy for control of annual and perennial weeds in elevated CO2 environments in agronomic crops. But limited information is available on how change in climate can affect herbicide efficacies in ornamental production. Hence, the objectives of this research proposal are: Evaluating increased temperature and CO2 levels on growth and reproduction of two different types of container-grown ornamentals; Determining effects of temperature and CO2 rise on preemergence herbicide performances for controlling C3 and C4 weed species; Determining effects of temperature and CO2 rise on postemergence herbicide performances for controlling C3 and C4 weed species; Assessing adaptive features of weed species with the change in environmental factors.

Speakers

Supti Saha Mou

Michigan State Univ.

Co-authors

Debalina Saha

Michigan State University

Thursday September 26, 2024 1:10pm - 1:20pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

1:20pm HST

WCPM 2 - Development of “EZA”, a New Pesticide Suitable for Organic Production of Horticultural Crops

Thursday September 26, 2024 1:20pm - 1:30pm HST

South Pacific 2

Production of economically important horticultural crops in the world, especially in developing countries, is faced with major challenges, including pests, and diseases. As a result, producers rely heavily on excessive use of synthetic pesticides, which often leads to negative impact to the environment, human health, and pesticide resistance. There is a need to develop environmentally friendly products to manage pests and diseases to increase crop yield, quality, and nutrition. Research was conducted in Rwanda to develop “EZA”, a new pesticide acting as an insect repellent, made of essential oils from local invasive plants such as Lantana camara, Tagetes minuta, and wastes of chili pepper and garlic. EZA was tested on tomatoes and mangoes under field conditions to manage several insect pests, including armyworms, fruit flies, thrips, and diseases such as tomato late blight caused by Phytophthora infestans. Results showed that EZA was effective in controlling insect pests, providing control of thrips and tomato late blight at the rate of 90% on 5 tomato plants where applied. Furthermore, tomato yield was increased by 40%. Information from this study demonstrates that EZA could significantly benefit horticultural crop producers, especially smallholder farmers in developing countries such as Rwanda, to effectively manage insect pests and diseases and the increase of crop yield.

Speakers

Merci Uwimbabazi

Kentucky State University

Thursday September 26, 2024 1:20pm - 1:30pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

1:30pm HST

WCPM 2 - Impact of Partial Saltwater Agroecosystems on Weed Competition in Watermelon

Thursday September 26, 2024 1:30pm - 1:40pm HST

South Pacific 2

The issue of soil salinity as a major cause of poor soil health and crop yield loss has been of growing concern as climate change contributes to its effects. The objective of this research was to study the impact of increasingly saline soils on the relationship between grafted watermelons and yellow nutsedge, one of the major weeds in watermelon plasticulture. The seedless watermelon cultivar Melody was grown in a field after being grafted onto the C. maxima hybrid Carnivor and the C. amarus cultivar Carolina Strongback in addition to both a self-grafted and ungrafted control. The field was divided into four rows, which were irrigated with 0, 10%, 20%, and 30% dilutions of sea water for the duration of the experiment. A weed count was performed after one month and three months of irrigation. This demonstrated that salt had a significant effect on the total weed count at high concentrations, however the weeds demonstrated a much greater resistance to salt treatment than the watermelons in this trial. Based on this data, it is possible that salt intrusion events can contribute to increased weed related yield loss in watermelon crops.

Speakers

Joseph Bazzle

Clemson University

Co-authors

A Levi

Brian Ward

Clemson University

H Schopp

Matthew Cutulle

Clemson University

Sandra Branham

Clemson University

Thursday September 26, 2024 1:30pm - 1:40pm HST
South Pacific 2

Poster presentation (individual talk), Weed Control and Pest Management 2

SUBJECT Weed Control and Pest Mgmt

1:59pm HST

Citrus Crops 3 (CITR 3)

Thursday September 26, 2024 1:59pm - 3:45pm HST

South Pacific 2

A Glimpse of The Future of Citrus in Florida – The Millennium Block - Flavia Tabay Zambon
Lessons from Evaluating New Varieties for the Indian River Grapefruit Industry - Flavia Tabay Zambon
Florida Citrus Rootstock Selection 5th Edition: Artificial Intelligence Enhanced Mobile Application for Growers - Andres GonzalezNeira
Australian Microcitrus-Derived Hybrids: Field Performance in Florida Under HLB Endemic Conditions - Matthew Mattia
The Citrus Genome Database: A Resource for Citrus Research and Crop Improvement - Jodi Humann
Comparative Transcriptomic and Metabolomic Studies Provide Insights into Early Tolerance Response of Citrus to CLas Infection - Zimmy Wang
Exploring Leaf Nutrients and Fruit Quality Attributes Relationship in Fresh Market Citrus Using Artificial Neural Networks and Linear Regression Models - Shankar Shrestha

Moderator

Flavia Tabay Zambon

University of Florida - IFAS - IRREC

Thursday September 26, 2024 1:59pm - 3:45pm HST
South Pacific 2

Oral Sessions, Citrus Crops 3

SUBJECT Citrus

2:00pm HST

CITR 3 - A Glimpse of The Future of Citrus in Florida – The Millennium Block

Thursday September 26, 2024 2:00pm - 2:15pm HST

South Pacific 2

For the past two decades, Florida citrus production has undergone a 75% reduction due to Huanglongbing (HLB), a disease caused by Candidatus Liberibacter asiaticus and vectored by the Asian Citrus Psyllid (ACP, Diaphorina citri). To combat this threat, breeding programs have been developing new varieties, seeking those tolerant to HLB while possessing other desirable traits and providing a long-term solution for the citrus industry. The Indian River Research and Education Center is leading this effort by planting new scion and rootstock varieties in four independent trials at the Millennium Block in 2019. One trial consists of 18 grapefruit-pummelo hybrid scions grafted onto three rootstock varieties, totaling 54 combinations (Trial 1). The other three trials are rootstock trials, where ‘Ray Ruby’ grapefruit (Trial 2), ‘Glenn Navel’ sweet orange (Trial 3), and ‘UF-950’ mandarin (Trial 4) varieties are grafted onto 32 rootstocks. The Millennium Block is home to 5,500 trees. Complete data for the 2023/24 season was collected, evaluating fruit yield, weight, size, and juice quality across all trials except for the mandarins, which have yet to set and keep a harvestable crop. Fruits were categorized into “good fruit” (based on shape, size, and maturity) and “bad fruit” (including visually HLB-affected fruit and off-bloom fruit). One of the 18 scions in Trial 1, a grapefruit-orange hybrid with golden flesh and high juice content called ‘Triumph,’ was discovered through a fortuitous mistake, yielding over 19,000 lb/ac of “good fruit” when grafted onto X-639, and had a Brix of 8.18. ’Triumph’ exhibits visual tolerance to HLB, with minimal to no affected fruit and no leaf symptoms. Of the red flesh grapefruit, ‘UF-914’ grafted onto ‘US-942’ and ‘X-639’ yielded close to 12,000 lb/ac of “good fruit” each, with juice Brix between 8-9. The traditional ‘Ray Ruby’ grapefruit has produced more boxes per acre grafted onto UFR-15 (close to 8,000 lb/ac) than US-942 and Sour Orange. Meanwhile, ‘Glenn Navel’ sweet orange yields more boxes when grafted onto US-942 (approximately 3,800 lb/ac), UFR-17, and Kuharske. The rootstock trials reveal that grapefruit and sweet orange scions require distinct rootstock characteristics to achieve the best yields. Data gathered by these trials are essential for growers to make informed decisions about which varieties to plant compared to the available conventional scions.

Speakers

Flavia Tabay Zambon

University of Florida - IFAS - IRREC

Co-authors

Macselynia Hossain

University of Florida

Mark A. Ritenour

University of Florida

Ronald D. Cave

University of Florida

Thursday September 26, 2024 2:00pm - 2:15pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

2:15pm HST

CITR 3 - Lessons from Evaluating New Varieties for the Indian River Grapefruit Industry

Thursday September 26, 2024 2:15pm - 2:30pm HST

South Pacific 2

Citrus greening is one of the deadliest bacterial diseases in citrus production. Caused by Candidatus Liberibacter asiaticus (CLas) and vectored by the Asian Citrus Psyllid (ACP, Diaphorina citri), the disease has devastated Florida’s citrus industry, reducing production by over 75% during the last twenty years. The Indian River Region, known for its premier grapefruit production, has suffered an intense decline in yield and acreage. Growers in the region have been fighting the pathogen and its insect vector, however, a long-term solution is required for sustainable grapefruit production. As no HLB resistance is known in commercially available cultivars, the University of Florida Breeding Program has bred new grapefruit hybrids with potential HLB tolerance. Plants developed through the program need to be field-tested. This study was initiated to evaluate new fresh grapefruit scion and rootstock breeding materials for HLB-tolerant. In collaboration with twelve growers across the state, a large trial was planted between 2020 and 2022 with 40 plots, each with forty-two scion/rootstock combinations totaling 12,000 trees. Among other tree growth data collected, fruit yield and quality were measured this season between October 2023 and March 2024. Results confirm that 'Jackson' grapefruit has some HLB tolerance, possibly due to its vigorous nature. However, its high fruit drop and inconsistent fruit set are persistent grower concerns. Among the newly developed grapefruit hybrids, 'UF N40-16-11-7' grafted onto SuperSour #1 and UFR-5, and the pummelo hybrid 'UF KW-50-1' grafted onto X-639 had low HLB disease indexes, equivalent to ‘Jackson’. On trees fruiting for the first time, the pummelo hybrid ‘UF KW-1-50’ grafted onto SuperSour #1 had the highest yield, mainly due to the pummelo heritage, followed by red grapefruit ‘UF N40-16-11-7’ also grafted onto SuperSour #1 and ‘Rio Red’ onto US-942. With tree ages ranging from 2 to 4 years, further data collection is needed to determine sustained yield and fruit quality. These results can help determine which combinations are most HLB-tolerant and best for planting in the Indian River Region.

Speakers

Flavia Tabay Zambon

University of Florida - IFAS - IRREC

Co-authors

Andres GonzalezNeira

University of Florida

Mark A. Ritenour

University of Florida

Thursday September 26, 2024 2:15pm - 2:30pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

2:30pm HST

CITR 3 - Florida Citrus Rootstock Selection 5th Edition: Artificial Intelligence Enhanced Mobile Application for Growers

Thursday September 26, 2024 2:30pm - 2:45pm HST

South Pacific 2

Florida citrus production has declined by 81% in total tonnage since 2020, mainly due to the deadly citrus greening caused by Candidatus Liberibacter asiaticus (CLas), a fastidious, phloem-limited, unculturable, gram-negative, α-proteobacterium vectored by the Asian Citrus Psyllid (ACP). Over $1.5 billion in funds have been mobilized since 2006 to overcome this disease. As an innate immune response, the infected plant deposits callose and p-protein in the phloem sieve pore, decreasing the flow of photoassimilates, leading to a rapid decline and, eventually, a plant collapse. The high cost of production has economically devastated Florida citrus growers. Using HLB tolerant rootstocks is one alternative to mitigate CLas effects, and the growers depend on the University to provide the most up-to-date recommendations. To address this, we have developed a convenient mobile application that uses artificial intelligence (AI) to assist growers in making the best rootstock selection for their groves based on horticultural traits, abiotic tolerances, and specific disease/pest incidences. The Florida Citrus Rootstock Guide Expert System 5th Edition is planned to be released by 2025 and is based on the information released in the previous editions. In addition to the release of the mobile application on all major platforms, an interactive web-based rootstock table has been updated with recent field data and newly released rootstocks. Historical and unavailable rootstocks are excluded from the selection list, increasing the incidence rate for a well-suited rootstock selection. Users can download, send, and retrieve rootstock reports on their mobile devices. The app’s design was generated from grower/user surveys to be as user-friendly as possible. The expert system is built on the ES-Builder Web application, McGoo Software, and is developed utilizing Google’s Dart programming language. The University of Florida is committed to establishing an AI-based university. The app's scalability will allow it to fully integrate into future AI projects to combat epidemics like citrus greening.

Speakers

Andres Gonzalez Neira

University of Florida - IFAS - IRREC

Co-authors

Flavia Tabay Zambon

University of Florida - IFAS - IRREC

John Chater

University of Florida

Mark Ritenour

University of Florida - IFAS - IRREC

Thursday September 26, 2024 2:30pm - 2:45pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

2:45pm HST

CITR 3 - Australian Microcitrus-Derived Hybrids: Field Performance in Florida Under HLB Endemic Conditions

Thursday September 26, 2024 2:45pm - 3:00pm HST

South Pacific 2

At the Queensland Department of Agriculture and Fisheries, the breeding program used native Australian citrus species (C. australasica, C. australis, C. garrawayi, and C. inodora), collectively referred to as Microcitrus, and cultivated Citrus. Commencing in 1998, this program aimed to introduce desirable Microcitrus traits into cultivated citrus, resulting in hybrids with pedigrees ranging from 12.5% to 100% Microcitrus. Previous studies suggest that specific Microcitrus accessions may exhibit resistance to huanglongbing (HLB), a disease associated with Candidatus Liberibacter asiaticus (CLas). To assess this resistance, we conducted tests on these Microcitrus-derived seedlings in a Florida field site where HLB and its vector, the Asian Citrus Psyllid (Diaphorina citri; ACP), are prevalent. Seeds were received in August 2015 and grown into field-ready seedling trees at the USHRL greenhouse. In August 2018, these trees were planted in a randomized layout at the Fort Pierce USDA grove, comprising 53 Microcitrus-derived populations alongside grafted Clementine and Hamlin standards. During 2020 and 2021, a subset of these plants underwent 24 assessments for ACP colonization, focusing on periods of abundant citrus flush and active D. citri presence. Data collected included observations of eggs, nymphs, and 5th instars, indicating D. citri's ability to complete development on the plant. Statistical analysis assessed variations in egg and nymph abundances concerning scion and date, revealing differing nymph counts across dates and scion types, with Hamlin and Arrufatina X 09Q048 displaying the highest nymph counts. Additionally, all trees were evaluated for CLas levels in October 2021 and no significant differences were found. The study encompassed seedling development, field planting, and standard citrus production practices, with minimal pesticide usage to determine the tolerance of Australian-derived hybrids to HLB.

Speakers

Matthew Mattia

USDA, ARS

Co-authors

Ed Stover

Retired (USDA,ARS)

Flavia Tabay Zambon

University of Florida - IFAS - IRREC

Malcolm Smith

QDAF

Thursday September 26, 2024 2:45pm - 3:00pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

3:00pm HST

CITR 3 - The Citrus Genome Database: A Resource for Citrus Research and Crop Improvement

Thursday September 26, 2024 3:00pm - 3:15pm HST

South Pacific 2

The Citrus Genome Database (CGD, www.citrusgenomedb.org) is a crop community database tailored for citrus researchers and breeders. CGD includes the Breeding Information Management System (BIMS) for both private breeding program management and publicly available phenotype and genotype data. Genetic data include genetic markers, maps, QTL, and GWAS curated from published and integrated with associated data in the database. The data is accessible via several search interfaces. Genetic maps can be viewed through the MapViewer tool, that also visualizes gene and genome data where available. CGD has over 40 genomes of Citrus and other genera in the Rutaceae family. For plant genomes, additional functional annotation and synteny analyses are conducted and made available to search. The genomes can be viewed in JBrowse, sequences searched using BLAST, genome synteny viewed with Synteny Viewer, and metabolic pathways for representative genomes can be viewed and users can overlay -omics data in CitrusCyc. Expression data associated with genes or mRNA of genomes in CGD are also available to view in the Expression Heatmap tool and on the feature page for the corresponding gene/mRNA. Ten bacterial genomes from Ca. Liberibacter and Liberibacter species are also available to search in the database, view in JBrowse, and search the sequences using BLAST. Researchers can also prepare and submit published data to the database using Excel based templates.

Speakers

Jodi Humann

Washington State University

Co-authors

Chun Huai Cheng

Washington State University

Dorrie Main

Washington State University

Fred Gmitter

University of Florida

Katheryn Buble

Washington State University

Ping Zheng

Washington State University

Ronald Tapia

University of Florida

Sook Jung

Washington State University

Taein Lee

Washington State University

Thursday September 26, 2024 3:00pm - 3:15pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

3:15pm HST

CITR 3 - Comparative Transcriptomic and Metabolomic Studies Provide Insights into Early Tolerance Response of Citrus to CLas Infection

Thursday September 26, 2024 3:15pm - 3:30pm HST

South Pacific 2

Citrus Huanglongbing (HLB, or citrus greening disease) has caused over 90% production losses since it was first reported in Florida in 2005. The unknown pathogenicity of the causative pathogen CLas hinders the development of sustainable disease management. Thus, understanding citrus host response to CLas, particularly at initial infection stage, is important for early disease detection and effective long-term HLB management. In this study, transcriptomic and metabolomic studies were conducted in a 2-day-post-inoculation (dpi) window, between HLB-tolerant LB8-9 Sugar Belle ® mandarin-like hybrid (SB; Citrus reticulata) and HLB- sensitive Valencia sweet orange (VAL; C. sinensis). CLas inoculation treatments included two controls no asian citrus psyllid (ACP) and CLas-negative ACP, plus CLas-positive ACP. Data were collevted at four time points: 2-, 12-, 24-, and 48-hour-post-inoculation (hpi). The results reveal that SB indicates immediate transcriptomic-level response from 2 hpi, compared with the delayed response in VAL from 24 hpi. The initial CLas-responsive differentially expressed genes (DEGs) in SB are related to plant defense response to Gram-negative bacterium, kinase activity and protein-kinase derived complex. DEGs that are categorized in plant defense response to Gram-negative bacterium are mostly associated with the pectinesterase inhibitors (PEIs) family which primarily alters the localized pH of the cell wall and strengthens cell wall integrity. On metabolomic level, SB shows rapid and high flavonoid content accumulation that reduces CLas-triggered stress and counteracts the initial infection. In VAL, the low flavonoid content accumulation removes reactive oxygen species (ROS) less efficiently which leads to more stress and cell death. Further investigation and validation on the proposed pathway are needed to confirm the early stage transcriptomic and metabolomic response of citrus tolerance response to CLas infection.

Speakers

Zimmy Wang

UF CREC

Co-authors

Frederick Gmitter

University of Florida

Jingwen Li

University of Florida

Ronald Tapia

University of Florida/IFAS Citrus Research and Education Center

Yu Wang

University of Florida

Thursday September 26, 2024 3:15pm - 3:30pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

3:30pm HST

CITR 3 - Exploring Leaf Nutrients and Fruit Quality Attributes Relationship in Fresh Market Citrus Using Artificial Neural Networks and Linear Regression Models

Thursday September 26, 2024 3:30pm - 3:45pm HST

South Pacific 2

The market value of fresh citrus fruit is greatly influenced by the internal and external fruit qualities, such as peel color, total soluble solids (TSS), titratable acid (TA), and fruit size. Abundance or deficiency of mineral nutrients in citrus trees are among the most important key factors that affect fruit qualities. Various regression models using leaf nutrient parameters and quality indices have been suggested, but their accuracy and generalization performance in estimating fruit quality remain insufficient. In this research, we used both artificial neural network models (ANN) and a multiple linear regression model to explore the effects of leaf nutrient concentration on citrus fruit quality. For ANN models, we applied two transfer functions and five different training functions to establish the model with best prediction accuracy using TensorFlow framework through Python software. The models were evaluated using statistical performance evaluation criteria including the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), and mean absolute relative error (MARE). Sensitivity analysis of the prediction models was conducted to discern the significant contribution of leaf mineral nutrients to the respective fruit quality parameters. The response surface analysis determined the optimal range of these mineral elements, which is critical for guiding precision fertilization in fresh market citrus fruit for improving fruit quality. Comprehensive results will be presented during the conference. Keywords: artificial neural network, fruit quality, citrus, mineral nutrients, sensitivity analysis

Speakers

Shankar Shrestha

PhD graduate student, University of Florida

Co-authors

Arnold Scumann

University of Florida

Thursday September 26, 2024 3:30pm - 3:45pm HST
South Pacific 2

Oral presentation (Individual talk), Citrus Crops 3

SUBJECT Citrus

4:00pm HST

Interest Group Session: Impacts of Horticultural Practices to Improve Soil Health

Thursday September 26, 2024 4:00pm - 6:00pm HST

South Pacific 2

With soil health and regenerative agriculture continuing to gain interest, the Hort Industry Professional Interest group invites you to join our session exploring the research behind soil health and how soil health is impacting horticulture today. This session will have speakers from across various horticultural disciplines discussing their research and the implications for soil quality, horticultural productivity, regenerative agriculture and environmental sustainability.

Coordinator(s)

Holly Little, Acadian Plant Health, Technology, Walnut Grove, Ca, United States

Moderator(s)

Derek Woolard, Valent Biosciences, United States

Speaker/Participant(s)

Justin Moss, Oklahoma State, United States
Urban Soil Health and Small Farm Soil Health (15 mins)
Summary:
Tai Maaz, University of Hawai'i, United States
Soil Health (15 mins)
Summary:
Noa Lincoln, UH Mānoa, Hilo, Hawaii, United States
Long Term Effects of Mono-Crop Conversion to Diversified Agroforestry (15 mins)
Summary:
Nhu Nguyen, University of Hawai'i, United States
Soil Microbial Ecology (15 mins)
Summary:
Amjad Ahmad, University of Hawai'i, United States
Organic Farming and Soil Health (15 mins)
Summary:

Moderator

Derek Woolard

Speakers

Noa Lincoln

Associate Professor - Indigenous Crops, University of Hawaii at Manoa

Noa Kekuewa Lincoln is an Associate Professor with a focus on Indigenous Crops and Cropping Systems, in the College of Tropical Agriculture and Human Resources at the University of Hawai'i at Mānoa, and the PI of the Indigenous Cropping Systems Laboratory. He is the President and... Read More →

Holly Little

Justin Moss

Tai Maaz

Nhu Nguyen

Amjad Ahmad

Thursday September 26, 2024 4:00pm - 6:00pm HST
South Pacific 2

Interest Group Session

SUBJECT Hort Industry

9:59am HST

Vegetable Crop Management 6 (VCM 6)

Friday September 27, 2024 9:59am - 11:45am HST

South Pacific 2

Field-Based Remediation Strategies for Groundwater Nitrogen Contamination
Can Healthy Soil Make Healthy People? Investigating The Impact Of Soil Biota On Micronutrient Uptake In Vegetable Crops
Optimizing nitrogen fertilizer concentrations in vegetable transplant production
Growing Resilient Broccolini: Harnessing Clover Living Mulch for Weed Suppression and Yield Enhancement
Foliage Removal on Processing Sweet Corn Reduces Yield Most Strongly Near Tasseling
Optimizing Planting Density of Sweet Corn in Georgia
Boosting Sweet Corn Yields: The Power of Biochar and Fertilizers Unveiled

Moderator

Hayley Milner

University of Georgia

Friday September 27, 2024 9:59am - 11:45am HST
South Pacific 2

Oral Sessions

SUBJECT Vegetable Crops

10:00am HST

VCM 6 - Field-Based Remediation Strategies for Groundwater Nitrogen Contamination

Friday September 27, 2024 10:00am - 10:15am HST

South Pacific 2

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

Speakers

Emma Schmidt

University of Wisconsin- Madison

Co-authors

Daniel Heider

University of Wisconsin-Madison

Jacklyn Slivicke

University of Wisconsin-Madison

Jed Colquhoun

University of Wisconsin

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

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

10:15am HST

VCM 6 - Can Healthy Soil Make Healthy People? Investigating The Impact Of Soil Biota On Micronutrient Uptake In Vegetable Crops

Friday September 27, 2024 10:15am - 10:30am HST

South Pacific 2

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

Speakers

Ashley Jernigan

Assistant Professor, Virginia Tech

Co-authors

Dennis Cladis

Virginia Tech

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

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

10:30am HST

VCM 6 - Optimizing nitrogen fertilizer concentrations in vegetable transplant production

Friday September 27, 2024 10:30am - 10:45am HST

South Pacific 2

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

Speakers

Emma Volk

UC Cooperative Extension

Co-authors

Bruno Pitton

University of California Cooperative Extension

Lorence Oki

University of California, Davis

Friday September 27, 2024 10:30am - 10:45am HST
South Pacific 2

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

10:45am HST

VCM 6 - Growing Resilient Broccolini: Harnessing Clover Living Mulch for Weed Suppression and Yield Enhancement

Friday September 27, 2024 10:45am - 11:00am HST

South Pacific 2

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

Speakers

Connor Ruen

South Dakota State University

Co-authors

Kristine Lang

South Dakota State University

Thandiwe Nleya

South Dakota State University

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

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

11:00am HST

VCM 6 - Foliage Removal on Processing Sweet Corn Reduces Yield Most Strongly Near Tasseling

Friday September 27, 2024 11:00am - 11:15am HST

South Pacific 2

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

Speakers

Charlie Rohwer

Scientist, University of Minnesota

Co-authors

Joe Lauer

University of Wisconsin-Madison

Mark Zarnstorff

National Crop Insurance Services

Friday September 27, 2024 11:00am - 11:15am HST
South Pacific 2

Oral presentation (Individual talk), Vegetable Crops Management 6

11:15am HST

VCM 6 - Optimizing Planting Density of Sweet Corn in Georgia

Friday September 27, 2024 11:15am - 11:30am HST

South Pacific 2

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

Speakers

Hayley Milner

University of Georgia

Co-authors

Juan Carlos Diaz Perez

University of Georgia

Nirmala Acharya

University of Georgia

Simerjeet Virk

University of Georgia

Ted McAvoy

University of Georgia

Friday September 27, 2024 11:15am - 11:30am HST
South Pacific 2

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

11:30am HST

VCM 6 - Boosting Sweet Corn Yields: The Power of Biochar and Fertilizers Unveiled

Friday September 27, 2024 11:30am - 11:45am HST

South Pacific 2

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

Speakers

Emilio Suarez Romero

University of Georgia

Co-authors

Henry Y Sintim

University of Georgia

Juan Carlos Diaz Perez

University of Georgia

Kate Cassity Duffey

University of Georgia

Ted McAvoy

University of Georgia

Friday September 27, 2024 11:30am - 11:45am HST
South Pacific 2

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops

11:59am HST

Commercial Horticulture 2 (CHEX 2)

Friday September 27, 2024 11:59am - 1:15pm HST

South Pacific 2

The Kentucky Small Fruits Initiative: An Extension-Industry Partnership - Cindy Finneseth
Case Study: Assessing Workforce Training Needs And UMKC Student Interest To Develop Controlled Environment Agriculture Education In Kansas City - Juan Cabrera Garcia
Assisting Florida Sod Producers with Protecting Water Quality by Quantifying Nutrient Inputs and Exports - Bonnie Wells
Will Consumers Purchase a Landscape Scouting Program? - Andrew Jeffers
Native Plant Extension Programming for Commercial Horticulture Professionals - William Errickson

Moderator

Cindy Finneseth

Kentucky Horticulture Council

Friday September 27, 2024 11:59am - 1:15pm HST
South Pacific 2

Oral Sessions, Commercial Horticulture 2

SUBJECT Commercial Hort

12:00pm HST

CHEX 2 - The Kentucky Small Fruits Initiative: An Extension-Industry Partnership

Friday September 27, 2024 12:00pm - 12:15pm HST

South Pacific 2

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

Speakers

Cindy Finneseth

Kentucky Horticulture Council

Co-authors

Daniel Becker

University of Kentucky

Delia Scott

University of Kentucky

Shawn Wright

University of Kentucky

Friday September 27, 2024 12:00pm - 12:15pm HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 2

SUBJECT Commercial Hort

12:15pm HST

CHEX 2 - Case Study: Assessing Workforce Training Needs And UMKC Student Interest To Develop Controlled Environment Agriculture Education In Kansas City

Friday September 27, 2024 12:15pm - 12:30pm HST

South Pacific 2

Controlled environment agriculture (CEA) integrates technology to optimize crop performance. The project goal was to inform the development of CEA curriculum by understanding CEA workforce training needs and gauging student interest at the University of Missouri – Kansas City (UMKC). CEA industry surveys determined the knowledge/skills needed for employment and educational expectations. A second survey was sent to UMKC students to gauge their knowledge of/interest in a CEA educational program. The top five positions in demand by the CEA industry were: (1) manager, (2) worker, (3) research

Speakers

Juan Cabrera Garcia

University of Missouri

Co-authors

Angela Cottrell

University of Missouri - Kansas City

Caroline Matz

University of Missouri - Kansas City

Karin Chang

University of Missouri - Kansas City

Friday September 27, 2024 12:15pm - 12:30pm HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 2

SUBJECT Commercial Hort

12:30pm HST

CHEX 2 - Assisting Florida Sod Producers with Protecting Water Quality by Quantifying Nutrient Inputs and Exports

Friday September 27, 2024 12:30pm - 12:45pm HST

South Pacific 2

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

Speakers

Bonnie Wells

University of Florida IFAS Extension

Dr. Bonnie Wells is the Commercial Horticulture Agent for the University of Florida IFAS Extension in Brevard County where she specializes in turfgrass and ornamental production and sustainable landscape maintenance. She is a Doctor of Plant Medicine (UF ’13) with more than 15 years... Read More →

Co-authors

Alex Lindsey

University of Florida

Bryan Unruh

University of Florida

Kevin Kenworthy

University of Florida

Marco Schiavon

University of Florida

Mark Tancig

University of Florida IFAS Extension

Matthew VanWeelden

University of Florida IFAS Extension

Friday September 27, 2024 12:30pm - 12:45pm HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 2

SUBJECT Commercial Hort

12:45pm HST

CHEX 2 - Will Consumers Purchase a Landscape Scouting Program?

Friday September 27, 2024 12:45pm - 1:00pm HST

South Pacific 2

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

Speakers

Andrew Jeffers

Clemson University

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

Co-authors

Bridget Behe

Michigan State University

Michael Vassalos

Clemson University

Sarah White

Clemson University

William Bridges

Clemson University

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

Oral presentation (Individual talk), Commercial Horticulture 2

SUBJECT Commercial Hort

1:00pm HST

CHEX 2 - Native Plant Extension Programming for Commercial Horticulture Professionals

Friday September 27, 2024 1:00pm - 1:15pm HST

South Pacific 2

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

Speakers

William Errickson

Rutgers University

Co-authors

Michele Bakacs

Rutgers University

Timothy Waller

Rutgers University

Timothy J Waller, Ph.D. is serving in his fourth year as the Commercial Nursery Agent of Rutgers Cooperative Extension in southern NJ, based out of Cumberland County. Tim has a Ph.D. in Plant Biology with a focus on fungal plant pathology and has been a licensed pesticide applicator... Read More →

Friday September 27, 2024 1:00pm - 1:15pm HST
South Pacific 2

Oral presentation (Individual talk), Commercial Horticulture 2

SUBJECT Commercial Hort

1:29pm HST

Marketing and Economics (MKEC)

Friday September 27, 2024 1:29pm - 2:00pm HST

South Pacific 2

Identifying the Ideal Combination of Strawberry Variety and Climate Control for Greenhouse Cultivation in Michigan -Amanda Jessica Da Silva
Economic impact of Winter Injuries on Golf Courses in North America - Chengyan Yue
Producing Sweet Potatoes to Manage Farm Income Risk in North Carolina - Godfrey Ejimakor

Friday September 27, 2024 1:29pm - 2:00pm HST
South Pacific 2

Poster Session, Marketing and Economics

SUBJECT Marketing and Economics

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

1:40pm 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

2:14pm HST

Ornamentals/Landscape and Turf 3 (O/LT 3)

Friday September 27, 2024 2:14pm - 3:30pm HST

South Pacific 2

Seedling Zoysiagrass Response to Fluazifop-butyl and Trifloxysulfuron-methyl With the Safener Metcamifen - Hannah Wright-Smith
Influence of Demethylation Inhibiting Fungicides on Creeping Bentgrass Putting Greens - Wendell Hutchens
Endophytic N Fixing Bacteria Isolated From Warm-season Turfgrasses and Common Lawn Weeds - Andrea F Arevalo Alvarenga
Mowing Mediated Root Radial Transport of Lead in Cynodon dactylon (L.) Persoon - Xinyi Cai
Cool-season Turfgrass Biomass and Ecosystem CO2 Flux as Affected by Fertilization and Irrigation - Ruying Wang
The 2023 Arkansas Diamond Plant Evaluation Trials - Anthony Bowden

Moderator

Hannah Wright-Smith

Extension Weed Specialist, University of Arkansas

Friday September 27, 2024 2:14pm - 3:30pm HST
South Pacific 2

Oral Sessions, Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

2:15pm HST

O/LT 3 - Seedling Zoysiagrass Response to Fluazifop-butyl and Trifloxysulfuron-methyl With the Safener Metcamifen

Friday September 27, 2024 2:15pm - 2:30pm HST

South Pacific 2

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

Speakers

Hannah Wright-Smith

Extension Weed Specialist, University of Arkansas

Co-authors

David Nistler

University of Arkansas

John McCalla

University of Arkansas

Lane Tredway

Syngenta

Michael D Richardson

University of Arkansas

Friday September 27, 2024 2:15pm - 2:30pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

2:30pm HST

O/LT 3 - Influence of Demethylation Inhibiting Fungicides on Creeping Bentgrass Putting Greens

Friday September 27, 2024 2:30pm - 2:45pm HST

South Pacific 2

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

Speakers

Wendell Hutchens

Assistant Professor of Turfgrass Science, University of Arkansas

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

Co-authors

Jessica Anders

University of Arkansas

Koa Grabar

University of Hawaii at Manoa

Michael Battaglia

University of Arkansas

Friday September 27, 2024 2:30pm - 2:45pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

2:45pm HST

O/LT 3 - Endophytic N Fixing Bacteria Isolated From Warm-season Turfgrasses and Common Lawn Weeds

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

South Pacific 2

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

Speakers

Andrea F Arevalo Alvarenga

Graduate Assistant, University of Florida

Co-authors

Marco Schiavon

University of Florida

Ulrich Stingl

University of Florida

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

Oral presentation (Individual talk), Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

3:00pm HST

O/LT 3 - Mowing Mediated Root Radial Transport of Lead in Cynodon dactylon (L.) Persoon

Friday September 27, 2024 3:00pm - 3:15pm HST

South Pacific 2

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

Speakers

Xinyi Cai

University of Georgia

Co-authors

Donglin Zhang

University of Georgia

Xi Li

Sichuan Agricultural University

Friday September 27, 2024 3:00pm - 3:15pm HST
South Pacific 2

Oral presentation (Individual talk), Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

3:15pm HST

O/LT 3 - Cool-season Turfgrass Biomass and Ecosystem CO2 Flux as Affected by Fertilization and Irrigation

Friday September 27, 2024 3:15pm - 3:30pm HST

South Pacific 2

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

Speakers

Ruying Wang

Oregon State University

Co-authors

Alec Kowalewski

Oregon State University

Claire Phillips

USDA-ARS

Clint Mattox

USDA-ARS

Emily Braithwaite

Oregon State University

Zachary Hamilton

Oregon State University

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

Oral presentation (Individual talk), Ornamentals/Landscape and Turf 3

SUBJECT Ornamental Landscape Turf

3:30pm HST

O/LT 3 - The 2023 Arkansas Diamond Plant Evaluation Trials

Friday September 27, 2024 3:30pm - 3:45pm HST

South Pacific 2

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

Speakers

Anthony Bowden

University of Arkansas

Co-authors

Randy Forst

University of Arkansas

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

Oral presentation (Individual talk), Consumer Horticulture and Master Gardeners

SUBJECT Consumer Hort and Master Gardeners, Ornamental Landscape Turf