ASHS 2024 Conference: Full Schedule

12:14pm HST

Vegetable Crops Management 1 (VCM 1)

Tuesday September 24, 2024 12:14pm - 1:50pm HST

Effect of Biostimulants on Emergence and Growth of Watermelon (Citrullus lanatus) Transplants. - Evan Christensen
Evaluation of Specialty Cucumber Cultivars in a High Tunnel Production System - Jacob Arthur
Are Locally Sourced Biochar and Poultry Litter the Solution to Improving Soil Health and Sustainably Producing Tomatoes? - Emilio Suarez Romero
Is Trellising Beneficial to High Tunnel Melon Yield? - Lewis Jett
Interseeded Clover Does Not Impact Pumpkin Yield - Charlie Rohwer
Protecting New Mexico’s Chile Crops from Curly Top Virus through Agrivoltaics - Mariela Estrada
Integrating High-resolution Satellite Imagery to Monitor Crop Growth and Yield: A Case Study of Japanese Squash and Onion in Hollister, California - Elia Scudiero
A New Tool to Manage Water and Nutrients in High Tunnel Tomato Production - Rebecca Brown
Soil Moisture Sensors Allow for Resilient Tomato Production in Organic Systems - Andre Luiz Biscaia Ribeiro da Silva
Physiology of Heat Tolerant Tomatoes: Transplanting Through Harvest - Courtney DeKalb-Myers

Moderator

Charlie Rohwer

Scientist, University of Minnesota

Tuesday September 24, 2024 12:14pm - 1:50pm HST
Nautilus 1

Poster Session, Vegetable Crops Management 1

SUBJECT Vegetable Crops

12:15pm HST

VCM 1 - Effect of Biostimulants on Emergence and Growth of Watermelon (Citrullus lanatus) Transplants.

Tuesday September 24, 2024 12:15pm - 12:25pm HST

Nautilus 1

The impacts of climate change and drought threatens water supplies that are necessary for watermelon production. Most production in the U.S. is seedless watermelon, typically grown in greenhouses and transplanted due to poor seed establishment in the field. Given the significance of high-quality transplants for the industry, we conducted a study to evaluate whether biostimulant products would improve transplant quality. In this study seven biostimulant products were tested on greenhouse-grown watermelon seedlings to measure seedling emergence and growth. Three bacterial (Continuum, Spectrum Ds, and Tribus Original), two mycorrhizal (MycoApply Endo, and Mighty Mycorrhizae), one humic (Huma Pro 16), and one seaweed extract product (Kelpak) were used. All products, except Kelpak, were incorporated into the growing media before sowing. Kelpak was applied at the first true leaf stage as a soil drench. Leaf area and root/shoot fresh and dry weight were measured over a 30-day period after stand establishment and data underwent analysis of variance (ANOVA) using SAS statistical software. Though some biostimulant products tended to have higher shoot and root weight they were not always significantly different, and the results were variable from trial to trial and analysis is ongoing.

Speakers

Evan Christensen

Utah State University

Tuesday September 24, 2024 12:15pm - 12:25pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

12:25pm HST

VCM 1 - Evaluation of Specialty Cucumber Cultivars in a High Tunnel Production System

Tuesday September 24, 2024 12:25pm - 12:35pm HST

Nautilus 1

Cucumbers are popular and high-value vegetable crops mainly marketed through local food markets for fresh consumption. Vegetable growers in Mississippi mainly operate on small to medium size farms. High value crops including tomatoes, peppers and cucumbers could be grown to increase competitiveness. Specialty cucumber cultivars including the parthenocarpic and mini types are in high demand due to their superior eating quality, these are often produced in protected environments like high tunnels or greenhouses. The objective of this study is to evaluate specialty cucumber cultivars and identify cultivars for superior yield and quality in the local climate under protected culture. This study was conducted in a high tunnel production system located at Mississippi State University through two growing seasons in 2022 and 2023. Twenty cucumber cultivars were evaluated including ten long Dutch/English slicer types: ‘Asteroid Long’, ‘Bologna Long’, ‘Boncanale Long’, ‘Davida Long’, ‘Durance Long’, ‘Georgia’, ‘Kasja Long’, ‘Tyria Long’, ‘Verdon Bio Long’, ‘Verdon Long’; five mini types: ‘Jawell Mini’, ‘Katrina’, ‘Manar Mini’, ‘Picolino’, ‘Socrates’; and four Asian types: ‘Itachi’, ‘Nokya’, ‘Unagi’, ‘Wokue’. The last cultivar ‘Striped Armenian’ is not a true cucumber and is actually part of the melon family. Plants were grown in 6-gallon containers using a modified drop line trellis system. Plant vegetative growth that was measured included plant height, stem diameter as well as soil plant analysis of development (SPAD). Cucumber fruits were harvested twice weekly, weighed for individual fruit weight, counted, and separated into marketable yield and unmarketable yield. Various fruit quality characteristics including: fruit diameter, fruit length, skin color, soluble solids content and fruit firmness were collected twice in each growing season. Cultivars varied in marketable and unmarketable yields in both growing seasons. In 2022, the cultivar ‘Picolino’ produced the highest marketable yield of 4.79 kg per plant with a majority of the other cultivars having statistically similar marketable fruit yields ranging from 2.87 kg in ‘Unagi’ to 4.75 kg in ‘Katrina’. The lowest marketable yield was produced by ‘Striped Armenian’ with 2.05 kg of marketable fruit for the entire growing season. Fruit quality parameters including soluble solids content, firmness, and fruit length had significant differences between cultivars. The cultivar ‘Kasja Long’ produced fruits with the highest soluble solids content of 4.18 °Brix, the other cultivars in this study had values ranging from 2.47 °Brix to 4.12 °Brix. The cultivars ‘Itachi’ and ‘Socrate’ produced the firmest fruit with values of 6.75 N and 6.70 N, respectively.

Speakers

Jacob Arthur

Mississippi State University

Co-authors

Guihong Bi

Mississippi State University

Tongyin Li

Mississippi State University

Tuesday September 24, 2024 12:25pm - 12:35pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

12:35pm HST

VCM 1 - Are Locally Sourced Biochar and Poultry Litter the Solution to Improving Soil Health and Sustainably Producing Tomatoes?

Tuesday September 24, 2024 12:35pm - 12:45pm HST

Nautilus 1

Agriculture is challenged by nutrient runoff, declining soil health, and high costs of inorganic fertilizers. This study investigates the potential of locally sourced biochar and poultry litter to address these issues by enhancing soil health and tomato production. Conducted in Spring 2023, the field trial assessed biochar application rates of 0, 10, 15, and 20 (tons/acre), combined with either organic (poultry litter) or inorganic fertilizer providing (225 N lbs/acre) for the growing period of the tomatoes. Utilizing a randomized complete block design, the experiment had four replications across ten treatments. The findings from this study revealed no significant differences in tomato yield between plants fertilized organically or inorganically across the various biochar application rates. Notably, the use of poultry litter as an organic fertilizer showcased promising results, particularly evident in the increased production of extra-large tomatoes. However, it also led to a higher count of culls. Biochar application significantly enhanced several key soil chemical properties, including pH levels, cation exchange capacity (CEC), and nutrient retention, especially at higher application rates. The incorporation of biochar was observed to substantially elevate soil pH by the season's end, attributed mainly to its considerable calcium content. A biochar application rate of (20 tons/acre) notably increased the pH to 6.8 in the inorganic treatment and even higher to 7.2 in the organic treatment when combined with calcium-rich poultry litter. In scenarios without biochar, the sandy loam soils exhibited a decrease in pH levels by the end of the season, indicating biochar's crucial role in counteracting soil acidification. The study also highlighted that a high biochar application rate significantly improved CEC in both inorganic and organic production systems by the season's end, facilitating better nutrient retention in sandy loam soils. Furthermore, higher biochar applications were associated with lower nitrate concentrations, while the absence of biochar in both treatments led to increased nitrate levels. This pattern was similarly observed with ammonium levels, where higher biochar applications resulted in reduced concentrations, suggesting that biochar effectively prevents the volatilization of ammonia. The research supports the hypothesis that biochar functions like a sponge, retaining essential nutrients within the soil matrix. This study provides evidence that biochar presents a viable strategy for organic and inorganic farmers to enhance soil chemical properties over the long term, offering a sustainable solution to improve agricultural practices and tomato production.

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

Tuesday September 24, 2024 12:35pm - 12:45pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

12:45pm HST

VCM 1 - Is Trellising Beneficial to High Tunnel Melon Yield?

Tuesday September 24, 2024 12:45pm - 12:55pm HST

Nautilus 1

Cantaloupes (Cucumis melo var. reticulatis) are a fruiting vegetable which grow best in warm environments. Cantaloupes also are infected by many foliar diseases which are triggered or exacerbated by rainfall and high relative humidity which is common during the growing season in Central Appalachia. One potential option for growing cantaloupes in West Virginia is high tunnel production. High tunnels significantly increase the air and soil temperature. In addition, the crop can be drip irrigated so there is no wet foliage for disease infection. Trellising may be necessary to facilitate harvest. Vertical trellising with pruning may be necessary for high tunnel production. Trellising can potentially increase marketable yield. However, trellis and pruning labor can be as high as $150/1000 ft2. Cantaloupes (cv. ‘Sugar Cube’) were transplanted within a high tunnel in 2023 and 2024. Vertical trellising and pruning were compared with non-trellised and non-pruned plants. Inputs such as labor and trellising supplies were recorded. In 2023, trellising did not significantly increase marketable yield of cantaloupes, but did significantly improve harvest efficiency.

Speakers

Lewis Jett

WVU

Tuesday September 24, 2024 12:45pm - 12:55pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

12:55pm HST

VCM 1 - Interseeded Clover Does Not Impact Pumpkin Yield

Tuesday September 24, 2024 12:55pm - 1:05pm HST

Nautilus 1

Pumpkins are usually grown using wide row spacing, and in Minnesota, the canopy does not close until mid-summer and the canopy senesces in early- to mid-autumn. This provides opportunity for establishing frost-tolerant or winter-hardy cover crops between rows before the canopy closes, which will continue to grow after pumpkin foliage is gone. To understand more about competition between interseeded cover crops and pumpkins, four species of clover (berseem, crimson, Persian, and red) were sown between pumpkin rows (10-ft spacing) in late June, and pumpkin yield and clover growth and N content were measured in the fall. Both ‘Cotton Candy’ and ‘Kratos’ pumpkins were studied. ‘Kratos’ yield (68.4 Mg / ha; 1185 fruit / ha), fruit size (9.7 kg), and fruit size variability (28%) were 1.8 times, 0.55 times, 3.2 times, and 1.1 times as much as ‘Cotton Candy’, but none of these responses were impacted by clover. Above-ground biomass of berseem, Persian, and red clovers averaged 0.41 Mg / ha in late fall (16 kg N / ha), but crimson clover yielded 1.2 Mg / ha (33.3 kg N / ha). Clover grown with ‘Kratos’ yielded 69% of the dry matter and 73% of the aboveground nitrogen (per ha) compared to clover grown with ‘Cotton Candy’. The average C:N ratio of all treatments was 18.3. These results show that clover interseeded into pumpkins, especially crimson clover, can grow successfully without impact on pumpkins. High-vigor pumpkins can reduce clover yield, however.

Speakers

Charlie Rohwer

Scientist, University of Minnesota

Tuesday September 24, 2024 12:55pm - 1:05pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:05pm HST

VCM 1 - Protecting New Mexico’s Chile Crops from Curly Top Virus through Agrivoltaics

Tuesday September 24, 2024 1:05pm - 1:15pm HST

Nautilus 1

Chile (Capsicum annuum) consumption and production have been integral to New Mexican culture for over four centuries, and the state is the leading producer of chile (non-bell peppers) in the United States. Chile farmers face adverse conditions due to climate change, water scarcity and disease control. One of the most prevalent chile diseases in NM is Beet Curly Top Virus (BCTV; Curtovirus). BCTV causes chlorotic curled leaves, stunted growth, abnormal or minimal fruit production, and a potentially substantial yield reduction. BCTV is transmitted by beet leafhoppers (Circulifer tenellus), insects that prefer feeding in areas exposed to full sun. Agrivoltaic systems (AVS), the co-location of solar panels in agricultural fields, increases field shade. Advantages of AVS have been examined, but its potential role as a deterrent for pests remains unknown. The aim of this study was to determine the impact of AVS shade on chile yields, beat leafhopper abundance, and BCTV incidence. On 16 May 2023 ‘NuMex Odyssey’, a New Mexico pod-type green chile was transplanted into four solar panel plots and a full sun control at the New Mexico State University Leyendecker Plant Science Research Center, Las Cruces, NM. Plots shaded by solar panels had an average of 15% less light radiation compared to the full sun control. Fruit was harvested on 21 Aug 2023 and sorted into marketable green, blossom end-rot affected, and curly top affected fruit. Preliminary results show that marketable green and blossom end-rot affected fruit yields did not differ between solar panel shaded and the full sun control plots. BCTV affected fruit yield was significantly greater in the full sun control, which also had 55% more trapped beet leafhoppers than the solar panel plots. Initial results show potential for AVS as a method to mitigate the adverse effects on chile yield caused by BCTV. In addition to alleviating crop stress, AVS has the potential to deter beet leaf hoppers while generating electricity, a potential extra revenue for the farmer.

Speakers

Mariela Estrada

New Mexico State University

Tuesday September 24, 2024 1:05pm - 1:15pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:15pm HST

VCM 1 - Integrating High-resolution Satellite Imagery to Monitor Crop Growth and Yield: A Case Study of Japanese Squash and Onio

Tuesday September 24, 2024 1:15pm - 1:25pm HST

Nautilus 1

Accurate monitoring of crop growth and estimations of yield are essential for optimizing agricultural practices and ensuring food security. Traditional approaches to monitor crop and map yield in vegetable crops often rely on ground-based observations, which can be time-consuming and labor-intensive. Remote sensing techniques offer a promising alternative by providing frequent and spatially extensive information on crop health and vigor. In this study, we aimed to assess the feasibility of using high-resolution satellite imagery to monitor crop growth and predict yield in Japanese squash (Cucurbita maxima) and onion varieties (Allium cepa) in Hollister, California, over the growing seasons of 2022 and 2023. Daily imagery from PlanetScope with a resolution of 3 m and on-demand 0.5 m imagery from Planet SkySat were utilized. Vegetation indices including the Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI) were calculated at various times during the growing season. Statistical analyses were performed to explore the correlations between these indices and crop yield. The results indicate significant correlations between vegetation indices such as NDVI and SAVI and crop yield in Japanese squash and onion varieties. Higher vegetation index values were associated with increased crop yield, suggesting that these indices can serve as reliable indicators of crop health and vigor. The use of high-resolution satellite imagery allowed for timely and accurate monitoring of crop growth dynamics, facilitating informed decision-making for growers. This study describes the potential of high-resolution satellite imagery and vegetation indices for monitoring crop growth and predicting yield in Japanese squash and onion varieties. The importance of integrating remote sensing techniques into agricultural practices to improve crop management strategies and enhance productivity will be discussed in the presentation.

Speakers

Elia Scudiero

University of California, Riverside

Co-authors

Nan Li

Univeristy of California, Riverside

Todd Skaggs

USDA-ARS

Tuesday September 24, 2024 1:15pm - 1:25pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:25pm HST

VCM 1 - A New Tool to Manage Water and Nutrients in High Tunnel Tomato Production

Tuesday September 24, 2024 1:25pm - 1:35pm HST

Nautilus 1

Much of the tomato production on market farms in the northeastern United States utilizes high tunnels. Tunnels protect soils from rainfall, reducing leaching of nutrients. However, if nutrients are accumulating below the root zone in tunnel soils lateral flow could be moving the nutrients beyond the covered area, resulting in leaching. From July 2020 to October 2022 we monitored soil moisture, soil temperature, and mineralization and movement of nitrate and phosphate in high tunnel tomato production on five commercial market farms (2 in Connecticut and 3 in Rhode Island). We also tracked irrigation water and fertilizer applications. Activated mixed-bed resin capsules were buried at 30 cm depth in transects running across the width of each high tunnel and extending 1 m past the tunnel perimeter on each side. Resin capsules were exchanged in March, July and October of each year and analyzed for captured nitrate, ammonium and phosphate. Soil P in the tunnels ranged from 16 to 363 kg/ha and soil K from 207 to

Speakers

Rebecca Brown

Co-authors

Josef Gorres

University of Vermont

Shuresh Ghimire

University of Connecticut

Tuesday September 24, 2024 1:25pm - 1:35pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:35pm HST

VCM 1 - Soil Moisture Sensors Allow for Resilient Tomato Production in Organic Systems

Tuesday September 24, 2024 1:35pm - 1:45pm HST

Nautilus 1

Soil moisture sensors have enabled continuous soil water status monitoring and became widely available to commercial growers. The use of soil moisture sensors that measure volumetric soil water content can be a useful tool to diminish or avoid over-irrigation addressing specific water requirements according to soil characteristics. However, the frequency of irrigation events, or a proper irrigation scheduling, using soil moisture sensor varies according to soil type, and the performance of soil moisture sensors as a tool to determine irrigation events on sandy soils used for organic vegetable production, particularly tomato, have not been evaluated up to date. Thus, the study objective was to evaluate the use of three irrigation scheduling strategies to enhance irrigation management in organic tomato production in the southeastern U.S. Field experiments were conducted on the organic unit at E.V. Smith Research and Extension Center from Auburn University, located in Shorter, AL in 2022 and 2023. Three irrigation scheduling treatments were tested: systematic irrigation (SYS), crop water demand (CWD), and soil water status method (SWS). In both years, results indicated that SWS had a higher biomass accumulation than CWD and SYS; consequently, tomato yield increased in the SWS compared to the two other treatments. Yield increments were 14% between SWS and CWD, and 25% between SWS and SYS. Irrigation water savings were also the highest for the SWS treatment, resulting in 72% water savings compared to SYS and 54% to CWD in 2022; while the SWS used 65% less water than SYS and 55% less than CWD in 2023. In general, rainfall events had an impact on strategies used to determine irrigation events. Among the studied irrigation scheduling methods, the SWS had a better performance in terms of fruit growth, biomass accumulation, and overall yield compared to CWD and SYS. Considering the global need for sustainable practices, the SWS treatment shows up as one of the best alternatives to the current grower standard practice, which consist in the SYS.

Speakers

Andre Luiz Biscaia Ribeiro da Silva

Auburn University

Co-authors

Camila Rodrigues

Auburn University

Guilherme Bueno

Auburn University

Timothy Coolong

University of Georgia

Wheeler Foshee

Auburn University

Tuesday September 24, 2024 1:35pm - 1:45pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:44pm HST

Vegetable Crops Management 1 (VCM 1)

Tuesday September 24, 2024 1:44pm - 3:45pm HST

Kahili

Nutsedge Management Through Soil Steaming - Shaun Broderick
Early Season Soil Tarping Impacts on Weed Pressure and Onion Production in Eastern South Dakota - Hannah Voye
Associations Among Crop/Weed Management Practices and Environmental Factors Highlight Challenges Facing U.S. Snap Bean Production - Martin Williams
Impact of Early Season Tarping on Soil Conditions and Weed Populations in North Central United States Vegetable Production Systems - Carly Strauser
Applying Advanced Lighting Practices for Vegetable Propagation - Rose Seguin
Evaluating the Effect of Three Algae Extracts Application on Three Crops Growth and Yield in Hawaii - Amjad Ahmad
Using the Feekes Growth Stage Scale to Predict the Carbon to Nitrogen Ratio of Cereal Cover Crops - Eric Brennan
Evaluating the effect of fertilization and controlled-water deficit on growth and yield of compact vegetable plants - Michael Fidler

Moderator

Shaun Broderick

Mississippi State University

Tuesday September 24, 2024 1:44pm - 3:45pm HST
Kahili

Oral Sessions, Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:45pm HST

VCM 1 - Physiology of Heat Tolerant Tomatoes: Transplanting Through Harvest

Tuesday September 24, 2024 1:45pm - 1:55pm HST

Nautilus 1

Consumers are motivated to purchase locally grown tomatoes for a maximum flavor experience. With this demand, tomatoes are highly valuable in the local food system and one of the most profitable crops for small, diversified farms. Tomato production in Oklahoma, and other warm climates, can be difficult with the fruit’s temperature requirements for fruit set. Optimum conditions are available for a short period in Oklahoma. The additional threat of climate change could present even more challenging growing conditions in the future. There are heat tolerant tomatoes available, but these cultivars still have an upper limit for stress exposure. Previous research shows that there are distinct physiological differences between heat tolerant and heat sensitive cultivars, but these evaluations focus primarily on the early stages of the plant’s development. We aim to investigate the differences in cultivars throughout the entire plant life cycle. A field experiment will include six cultivars at different planting dates, showing a range of responses. The three planting dates will impose different temperature regimes throughout plant development. Physiological measurements will be recorded at regular intervals from transplanting through harvest. These parameters will include chlorophyll fluorescence, stomatal conductance, and electrolyte leakage. The results will assist with development of a model that enhances Oklahoma tomato production capacity through optimizing cultivar selection.

Speakers

Courtney DeKalb-Myers

Co-authors

Justin Moss

Oklahoma State University

Tuesday September 24, 2024 1:45pm - 1:55pm HST
Nautilus 1

Poster presentation (individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

1:45pm HST

VCM 1 - Nutsedge Management Through Soil Steaming

Tuesday September 24, 2024 1:45pm - 2:00pm HST

Kahili

Soils host weeds, pathogens, and insects that can cause crop damage and reduce yield. Many methods have been developed to reduce these pressures within the soil, including soil solarization, chemigation, anaerobic soil disinfestation, and soil steaming. We have utilized soil steaming to reduce weed seeds and soil infestation in high tunnel and field tomato (Solanum lycopersicum) production. While it successfully reduces most weed species and southern blight (caused by Athelia rolfsii) in tomatoes, the emergence of nutsedge (Cyperus spp.) in soils with established populations can increase after steaming. Our research goal was to evaluate the efficacy of various soil preparation methods prior to steaming to allow the steam to penetrate the soil and target nutsedge directly. Except where noted, the field was first chisel plowed, disced, and then shaped into 2-foot-wide by 6-inch-tall beds. We compared 8 preparation methods for controlling nutsedge: a no-till control, herbicide control using S-metolachlor and halosulfuron-methyl, 6-inch-tall bed size, 12-inch-tall bed size, chisel plowed row, black plastic mulch, 4-inch-deep trenches on no-till, and 6-inch-deep trenches on no-till. Four trenches were cut into the soil with a soil trencher for each plot. Four replicates were included in a completely randomized design. Half of each bed was steamed until temperatures reached 160 °F, 4 inches deep, except for the herbicide beds and mulched beds, which were left unsteamed. Four sets of temperature probes were placed 12, 8, 6, and 4 inches deep in the soil and temperatures and used to monitor temperature changes in steam soils over time. Nutsedge coverage was visually estimated by placing a 1 by 6-foot rectangular PVC frame in each row over a representative section. 12-inch-tall beds had nearly 100% nutsedge coverage, while 6-inch-tall beds had nearly 50%. Herbicides reduced nutsedge coverage to 29%, and the plastic mulch reduced coverage to 8%. The steamed no-till, 4-inch trench, 6-inch trench, and chisel-plowed beds had no nutsedge emergence through the trial. The 6-inch-tall beds had lower temperatures at 6 and 8 inches deep than the other methods, which could account for the observed increases in nutsedge emergence post steaming. The time-consuming nature of soil trenching would make it impractical for most horticultural production settings; however, the chisel plow and no-till could be readily adopted. Determining effective methods to prepare the fields for soil steaming to reduce or eliminate nutsedge will make soil steaming a more viable method for organic farmers facing nutsedge pressures.

Speakers

Shaun Broderick

Mississippi State University

Co-authors

Christine Coker

Mississippi State University

Te Ming Tseng

Mississippi State University

Tuesday September 24, 2024 1:45pm - 2:00pm HST
Kahili

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

2:00pm HST

VCM 1 - Using the Feekes Growth Stage Scale to Predict the Carbon to Nitrogen Ratio of Cereal Cover Crops

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

Kahili

Cereals and other non-legume cover crops can help vegetable farms to reduce nitrogen leaching to ground water during rainy winter periods. A cover crop’s carbon to nitrogen ratio is an important metric that can help farmers better understand the nitrogen release dynamics from soil-incorporated cover crops. Cover crops with a lower C:N ratio (15:1) typically mineralize nitrogen when they are incorporated into the soil, whereas those with a higher C:N (25:1) usually immobilize nitrogen. But farmers need simple, reliable, field-based methods to predict a cover crop’s C:N ratio. Therefore, we evaluated the relationship between the Feekes growth stage scale and the C:N ratio of rye (Secale cereale L., ‘cv. Merced’) and triticale (X Triticosecale Wittmack, cv. ‘Pacheco’) cover crops in the Central Coast region of California. Over a hundred field samples of rye and triticale shoots were collected at various developmental growth stages from organic and conventional vegetable farms and planting date trials, across multiple soil types, planting times, row spacings, and plant densities. The Feekes scale was correlated with the C:N ratio of cover crop shoots of rye (r2=0.63) and triticale (r2=0.76). The transition from Feekes 9 (when the ligule of the flag leaf is visible) to Feekes 10 (‘boot’ stage) is roughly when the C:N ratio went from below to above 20:1. Regression plots were developed that illustrate the relationship between the Feekes scale and the C:N ratio. These results have practical implications for a new ground water protection regulation (Ag. Order 4.0) in California’s central coast region that incentivizes winter cover crops that are grown until the C:N ratio is 20:1 or more.

Speakers

Eric Brennan

USDA-ARS

Co-authors

Richard Smith

University of California Cooperative Extension

Tuesday September 24, 2024 2:00pm - 2:15pm HST
Kahili

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

2:15pm HST

VCM 1 - Associations Among Crop/Weed Management Practices and Environmental Factors Highlight Challenges Facing U.S. Snap Bean Production

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

Kahili

Snap bean production has decreased by ~30% recently due to an increase in imports and changing consumer preferences towards more fresh and frozen products. A major production concern is weed species that escape control, since they cause yield losses and can contaminate harvest loads. Coupled with changing weather patterns, snap bean processors and growers will have to adjust to these and future challenges. Field surveys were conducted to identify associations among crop/weed management practices and environmental factors on snap bean yield and weed density. From 2019-2023, snap bean fields throughout the major U.S. production regions were surveyed for weeds at harvest. Management records for each field were obtained from growers. Information on soil and weather conditions of each surveyed field also was obtained. In total 358 production fields were surveyed in the Midwest (Illinois, Iowa, Minnesota, Wisconsin), Northeast (Delaware, Maryland, New York. Pennsylvania), and Northwest (Oregon, Washington) regions. To determine associations among management and environmental variables on crop yield and weed density, the machine learning algorithm random forest was utilized. The models had 24 and 22 predictor variables for crop yield and weed density, respectively, and both were trained on 80% of the data with the remainder used as a test set to determine model accuracy. Partial dependence plots were used to visualize the change in response variables based on the most important predictors. The crop yield model had pseudo-R2 values of 0.56 and an accuracy of 74%. Higher average temperatures during early season growth, higher soil organic matter content, and planting midseason (June-July) predicted an increase in average crop yield. Meanwhile, excessive precipitation early in the season, high sand content of the soil, high temperatures at crop flowering and row cultivation predicted a decrease in crop yield. The weed density model had pseudo-R2 values of 0.55 and an accuracy of 81%. While row cultivation was associated with lower snap bean yield, it corresponded to a decrease in weed density, suggesting row cultivation had less-than-ideal selectivity between the crop and weed. Moreover, multiple spring tillage operations prior to planting predicted an increase in average weed density, implying that excessive tillage may favor emergence of weeds in snap bean. Over the coming decades, climate change-driven weather variability is likely to influence snap bean production, both directly through crop growth and indirectly through weeds that escape control practices that also are influenced by the weather.

Speakers

Martin Williams

USDA-ARS

Co-authors

Barbara Scott

University of Delaware

Carolyn Lowry

Penn State University

Edward Peachey

Oregon State University

Jed Colquhoun

University of Wisconsin

Lynn Sosnoskie

Cornell University

Mark VanGessel

University of Delaware

Nicholas Korres

University of Ioannina

Pavle Pavlovic

University of Illinois Urbana-Champaign

Rui Liu

Washington State University

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

2:30pm HST

VCM 1 - Impact of Early Season Tarping on Soil Conditions and Weed Populations in North Central United States Vegetable Production Systems

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

Kahili

Weed management is one of the biggest challenges vegetable growers face. Plastic mulch, herbicides, tillage, and hand-weeding are common ways vegetable growers manage weeds. These methods can be labor intensive, require specialized equipment, and cause environmental harm. Tarping is an alternative weed management method. Silage tarps or high-tunnel plastics are commonly used tarping materials; these are multi-functional tools that can be used for several years. Tarping facilitates stale seedbed weed management techniques by modifying the soil microclimate and promoting weed germination. After weed germination, opaque tarps can terminate weeds via occultation (lack of sunlight), whereas clear tarps terminate weeds by creating extreme temperatures. More information is needed for the type and timing of early-season tarp application for optimal weed control. The research was conducted at the Iowa State University Horticulture Research Stations in Ames, IA. This study examined three types of tarps: black, white, and clear, at three different durations: two, four, and six weeks prior to planting compared to a non-tarped control. Clear tarp and control treatments were cultivated at the time of tarp removal prior to planting. Soil temperature was recorded at 5 centimeters depth for 6-week tarp treatments. Early-season clear tarping did not elevate temperatures enough to terminate the majority of weeds. However, black and white tarps created a weed-free planting bed. Average soil temperatures underneath the clear tarp were the warmest (21.8ºC), followed by black tarp (15.1ºC). White tarp treatments (11.7ºC) had a lower average soil temperature than treatments with no tarp (14.8ºC). Two weeks following tarp removal, six-week clear tarp treatments had a higher percent weed cover than black and white tarp treatments measured using Turf Analyzer, a digital photo analysis software. Differing soil temperatures did not significantly impact soil microbial biomass carbon. The two-week white tarp had significantly higher soil microbial biomass nitrogen than all other treatments except four-week clear tarp. There was no effect of tarp type or duration on onion crop yield. These results indicate that the use of white and black tarps can be a feasible alternative weed management method in North Central vegetable production systems.

Speakers

Carly Strauser

Iowa State University

Graduate Research Assistant, Department of Horticulture at Iowa State University

Co-authors

Ajay Nair

Iowa State University

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

2:45pm HST

VCM 1 - Applying Advanced Lighting Practices for Vegetable Propagation

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

Kahili

Propagation greenhouses produce a wide range of crops, each presenting unique responses to light quality and quantity. With dynamic LED lighting solutions now available and proven to be viable over large acreages, propagators can tailor their lighting protocols to each crop with regards to zone management, photoperiod, spectrum and intensity. The effects of light quality and quantity on plant morphology and growth are well documented and while the exact impact is not generalizable across all crops and varieties, certain themes hold true. For example, high levels of blue light are generally associated with compact plants and thick, waxy leaves. In contrast, high levels of far-red light can cause etiolation in multiple species through the shade avoidance response but enhances photosynthesis and growth when combined with red light. Given the high importance of crop morphology in propagation, dynamic Dynamic LED lighting has been used to develop advanced lighting protocols in the propagation of fruit, vegetable and ornamental crops. In the production of cucumber transplants, applying high levels of blue light and a long photoperiod effectively slows the growth of cucumber transplants at the end of the propagation cycle, a strategy which proved useful to a propagator looking to delay transplant delivery per the client’s request. Concretely, the combination of high blue levels and a long photoperiod slowed crop growth, prevented tendril development and restricted plant stretching. Further, the use of high-blue treatments over young leafy greens effectively reduced plant height by 2-3 cm and produced stronger plants. Another trial focused on the production of strawberry tray plants found that a balanced light spectrum produced more stolons (i.e., daughter plants) while a blue-enriched spectrum produced significantly more leaves. In the production of ornamentals, dynamic lighting can be used to reduce the greenhouse’s reliance on plant growth regulators (PGRs), enhance leaf or petal coloration and trigger bud formation. In red-leafed varieties, controlled light-induced plant stress through spectral and/intensity adjustments have proven effective at stimulating the production of red pigments and enriching the leaves’ hue. Results from various commercial and research trials demonstrate benefits of dynamic LED lighting in the propagation of horticultural and ornamental crops alike. This presentation presents data from the aforementioned case studies among others.

Speakers

Rose Seguin

Agronomist, Sollum Technologies

Rose Séguin is an agronomist specializing in controlled environment agriculture, with previous experience in indoor agriculture, agricultural innovation systems, and agricultural development in remote areas of Canada. She holds a bachelor's degree in agro-environmental sciences and... Read More →

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

3:00pm HST

VCM 1 - Evaluating the Effect of Three Algae Extracts Application on Three Crops Growth and Yield in Hawaii

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

Kahili

Food- and nutritional-security are among the highest concerns for Hawaii residents. The state imports about 85% of the consumed food and there’s roughly two-week worth of food locally at any given time. Local food production is costly due to high inputs cost. Algae extracts are known to supports plants' flowering and fruiting, increasing plant nutrient uptake, enhancing resistance and recovery from plant stress events, and increasing nutrient use efficiency and fertilizer assimilation. Three different algae extracts (Afrikelp, Acadian, and Kelpak) were evaluated for their effect on growth and yield of bush bean, bell pepper, and tomato in a randomized complete block design (RCBD) with 5 blocks. The algae extracts were applied 5 times during each growing season. The algae extracts were applied at dilution rate of 1:100 with a week between applications for the bush bean crop and two-week intervals for bell pepper and tomato crops. The results showed a highly significant (p < 0.01) increase in the three crops yield under all algae extracts compared to control (water only) treatment. The results also showed there was a significant (p < 0.05) difference between the algae extracts with highest yield recorded under Afrikelp extract compared to Acadian and Kelpak. The yield increase reached between 150-300% compared to control treatment.

Speakers

Amjad Ahmad

Co-authors

Joaquin Orellana Correa

Afrikelp

Natalia Santibanez

Afrikelp

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

3:15pm HST

VCM 1 - Early Season Soil Tarping Impacts on Weed Pressure and Onion Production in Eastern South Dakota

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

Kahili

Onions are a globally popular kitchen staple, not only for their flavor, but also their nutritional value. According to the Agricultural Marketing Research Center, onions are the fourth most consumed fresh vegetable in the United States. To bring this valued crop to our kitchen tables, quality onions must be produced in high quantities to meet consumer demands. Since they are especially susceptible to weed competition due to their minimal canopy cover, weed management is an important consideration for onion production. One weed management tool is soil tarping. This study evaluated the impact of two types of tarping (solarization and occultation) and duration of tarping (6-, 4- and 2-weeks) on weed control in Patterson and Candy onion production. Field experiments were conducted during the 2023 growing season in Brookings, South Dakota. Solarization was conducted using clear tarps secured with sandbags and buried edges. Tarps were placed in April and May at respective weeks before removal on May 30. Immediately following tarp removal, each plot was tilled, and rows of onion transplants were planted. Occultation was evaluated using white side up and black side up silage tarps, both applied at respective weeks before removal and onion planting. Each treatment plot filled a twenty-four by ten-foot area. A randomized complete block design with four blocks and ten treatment plots per block including a control with no tarp was established. Response variables for data collection included weed type, height, and biomass as well as onion yield. All tarping treatment plots resulted in less weed pressure than the control at tarp removal. Broadleaf weed count collected during the growing season was different among tarp treatments (p=0.03). Data collected June 12 showed 6-week clear tarp to have 67% less broadleaf weed count per acre than the control, and 74% less than the 4-week black tarp. There was no difference in onion yield due to tarping treatment. This may have been due to biweekly weeding events that evened out treatment effect on weeds over the growing season. There was, however, a difference in yield between Candy and Patterson onion cultivars (p=0.02). Candy averaged a marketable count of 19 of 48 planted onions while Patterson averaged a marketable count of 36 of 48 onions planted. Soil tarping may be an effective option for farmers to reduce early season weeds in onion production, however, it should be used alongside other management strategies to obtain a viable yield.

Speakers

Hannah Voye

South Dakota State University

Co-authors

Kristine Lang

South Dakota State University

Rhoda Burrows

South Dakota State University

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Vegetable Crops

3:30pm HST

VCM 1 - Evaluating the effect of fertilization and controlled-water deficit on growth and yield of compact vegetable plants

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

Kahili

Sales of compact vegetable bedding plants for the home-gardening market segment are increasing. However, production guidelines for these new crops are limited. Our objective was to assess the effect of fertilizer use and controlled-water deficit (CWD) on plant growth during production, and after-production effects on fruit yield. ‘Siam’ tomato and ‘Basket of Fire’ pepper plants were grown in a greenhouse for 4 and 6 weeks, respectively, using 10-cm containers. Half of the plants received a water-soluble fertilizer once a week, and the other half were irrigated with tap water only, relying on the starter fertilizer charge in the substrate (EC = 0.9 mS·cm−1). Plants were irrigated when the substrate volumetric water content (VWC) reached 0.15, 0.30, 0.45, or 0.60 m3·m–3. After the experiment, plants were transplanted into 20-cm containers, top-dressed with controlled-release fertilizer (CRF), and grown for another 10 weeks to evaluate carryover treatment effects. Plants that did not receive fertilizer were shorter and had a lower shoot dry mass (SDM) than those that were fertilized, regardless of species. Shoot height of tomato followed a quadratic trend in response to CWD, which peaked at 0.45 m3·m–3, whereas SDM linearly increased with increasing VWC. No growth responses to CWD were measured for pepper. However, plants of both species that did not receive fertilizer looked chlorotic and had a lower chlorophyll concentration than those that were fertilized (15 and 32 µmol·m–2 for tomato and 15 and 27 µmol·m–2 for pepper, respectively). Plant greenness increased after applying CRF, suggesting that applying fertilizer right before shipping could increase quality of these plants when grown with limited or no fertilizer to control growth. After the carryover phase, differences in plant growth were maintained, and differences in yield was measured between fertilized and non-fertilized plants (56 and 48 fruits for tomato and 153 and 112 fruits for pepper, respectively). Our results show that growth and yield of compact tomato and pepper plants are affected to a larger extent by fertilizer use than by substrate VWC.

Speakers

Michael Fidler

Purdue University

Co-authors

Celina Gomez

Purdue University

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

Oral presentation (Individual talk), Vegetable Crops Management 1

SUBJECT Plant Growth Regulation, Vegetable Crops

7:59am HST

Vegetable Crops Management 2 (VCM 2)

Wednesday September 25, 2024 7:59am - 10:00am HST

South Pacific 4

Optimizing Tomato Crop Production: Fertility Management in Soilless Media - Bryce Waugh
Improving the Growth and Yield of Tomato through new Integrated Pest Management Strategies - Rosemary Gutierrez Coarite
Assessment of Novel, Interspecific Hybrid Tomato Rootstocks for Production under Environmental Stress - Joshua Harvey
Evaluation of Biostimulant on Nutrient Use Efficiency in Tomato - Weining Wang
Alternative Carbon Sources Effects on the Soil-plant Nutrient Dynamics During and Post ASD in a High Tunnel Tomato Crop System - Francesco Di Gioia
Advancing Pepper Production Beyond Seasonal Limits: Findings from a High Tunnel System Integrated with Biostimulant Applications - Asmita Nagila
Optimizing Nitrogen Fertilizer Rate and Planting Density of Vidalia Onion Yield and Bulb Size Distributions - Elvis Pulici
Assessing the Efficacy of Plant Biostimulants on Onion Growth and Production in Greenhouse Trials and Field Conditions - Prakriti Nepal

Moderator

Francesco Di Gioia

Pennsylvania State University

Wednesday September 25, 2024 7:59am - 10:00am HST
South Pacific 4

Oral Sessions, Vegetable Crops Management 2

SUBJECT Vegetable Crops

8:00am HST

VCM 2 - Optimizing Tomato Crop Production: Fertility Management in Soilless Media

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

South Pacific 4

Tomatoes are one of the most important greenhouse produced crops and the number of producers using greenhouse to grow them has risen in recent years. Sustainable development and effective resource management are becoming more and more important to the agricultural industries as well. Applying fertilizer precisely is becoming more and more important in different agricultural systems. Different physical and chemical characteristics of soilless growing substrate result in varying capacities for retaining nutrients. As a result, precise fertilizer rates are essential. This study investigated 14 fertilizer blends with varying proportions of nitrogen (0-400ppm), phosphorus (0-100ppm), and potassium (0-425). Six-cell seedling starter trays were filled with Berger BM6, and 'Big Beef' tomato seeds were planted. After four weeks, the seedlings were transplanted into five-gallon aeration fabric grow bags. Plants were hand-watered once a week with each treatment fertilizer rate to maintain a 10% leaching fraction. End measurements included the number of leaves, dry shoot weight, fresh root weight, dried root weight, and SPAD readings. The study revealed that a higher rate of nitrogen increased fresh shoot weight and lower rates of phosphorous increased number of non-harvestable fruits, increasing the need for further investigation to determine optimal fertilizer rates for various specialty crops grown in soilless greenhouse environments. Such endeavors are crucial for maximizing agricultural productivity while minimizing resource wastage and environmental impact.

Speakers

Bryce Waugh

Grad Student, Oklahoma State University

Co-authors

Bruce Dunn

Oklahoma State University

Wednesday September 25, 2024 8:00am - 8:15am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

8:15am HST

VCM 2 - Improving the Growth and Yield of Tomato through new Integrated Pest Management Strategies

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

South Pacific 4

Tomato (Solanum lycopersicum L.) is the number one vegetable crop in Hawaii in terms of popularity and market value. Of the total tomatoes consumed in Hawaii only 23% is produced locally. Local production has decreased substantially over the past few years due to crop losses caused primarily by the Tomato Yellow Leaf Curl Virus (TYLCV), which is vectored by whiteflies Bemisia tabaci and Bemisia argentifolii. Crop losses by TYLCV in tomato crops on Maui range between 60 to 100%. Efforts to keep plants from becoming infected, manage the rate of infection, timing, or severity of the infection are needed to protect crop health. Therefore, a new integrated pest management approach was conducted integrating the use of reflective ground cover, companion plants, insecticides, and tomato varieties resistant to TYLCV. The highest total weight (4.4 lb/pl per harvest time) was observed in the variety PS01522935 in the treatment combining reflective ground cover and companion plants and the highest marketable weight was observed in the same treatment in the varieties PS01522935 and Mesquite (3.5 lb/pl per harvest time), and the highest TYLCV infection was observed in the conventional treatment in the varieties Paisano followed by Healani, Celebrity Plus and Kewalo, and the varieties with no TYLCV infection were PS01522935, SVTD8601 and Mesquite. The use of reflective ground cover and companion plants may reduce TYLCV infections in tomato crops by reducing whitefly populations.

Speakers

Rosemary Gutierrez Coarite

University of Hawaii at Manoa

Wednesday September 25, 2024 8:15am - 8:30am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

8:30am HST

VCM 2 - Assessment of Novel, Interspecific Hybrid Tomato Rootstocks for Production under Environmental Stress

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

South Pacific 4

A growing global population and worsening global environmental change necessitate the development of improved crop varieties and cultivation techniques. In tomatoes, the world’s most popular vegetable crop, grafting has emerged as a cultivation technique for addressing these challenges through improving tomato crop vigor and stress resistance, especially to abiotic stresses that are becoming more widespread including heat, salinity, and drought stress. In order to expand the offerings of tomato rootstocks, we have conducted multiple trials to assess the beneficial impact of 10 novel tomato rootstocks on ‘Celebrity’ scion vigor and stress resistance. The rootstocks, developed by colleagues at the King Abdullah University of Science and Technology (KAUST) consist of interspecific Solanum spp. hybrids including two tetraploid hybrids. We conducted three trials to assess the impact of grafting with the novel rootstocks, including a greenhouse pot trial to quantify growth and vigor and two controlled environment trials to assess stress resistance. In each trial, ‘Celebrity ’ scions were grafted with either the novel rootstocks, ‘Maxifort’, ‘Multifort’, or left ungrafted. In the greenhouse trial, measurements of stem diameter, shoot height, shoot canopy projection area, and fresh and dry weights at harvest were used to determine overall vigor. We identified five and eight of the novel rootstock grafting combinations that outperformed the ungrafted and ‘Maxifort’-grafted plants, respectively. Additionally, measurements of SPAD and observations of foliage coloration provided initial evidence of differential nutritive requirements between the novel rootstocks. In our controlled environment trials, chlorophyll fluorescence, SPAD, and porometer data demonstrated differential susceptibility to salinity, heat, and drought stress between the rootstocks. This presentation will highlight key differences in morphological and physiological traits that assisted us in selecting a narrow set of rootstocks for a forthcoming evaluation in a passive high tunnel to demonstrate the utility of these new rootstocks.

Speakers

Joshua Harvey

Texas A

Co-authors

Daniel Leskovar

Texas A

Nathaly Rodriguez Ortiz

King Abdullah University of Science and Technology

Wednesday September 25, 2024 8:30am - 8:45am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

8:45am HST

VCM 2 - Evaluation of Biostimulant on Nutrient Use Efficiency in Tomato

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

South Pacific 4

To evaluate the efficacy of a commercial available biostimulant (a product containing friendly microorganisms like N2 fixing bacteria) on the improvement of nitrogen (N) and phosphorus (P) use efficiency in tomato, two independent field experiments were conducted in West Central Florida in the fall production season of year 2023. For both experiments, treatments included a factorial combination of two biostimulant rates (0 or 0.247 kg/ha) and four fertilizer rates (N or P2O5) (0, 67, 135, 202 or 269 kg/ha) that were arranged in a split-plot design. Biostimulant was applied as a solution drenched in soil following transplanting, and fertilizer treatments were applied as pre-plant application in soil and/or through drip injection during the season. Commercial tomato cultivar ‘HM1823’ was chosen as plant material. Analysis of variance (ANOVA) revealed that biostimulant did not have statistically significant influence on fruit marketable yield, fruit quality (Brix) and plant biomass, regardless of application rates of P2O5. By contrast, however, application of N had statistically (P

Speakers

Weining Wang

University of Florida

Co-authors

Lakesh Sharma

University of Florida

Dr. Lakesh Sharma is an assistant professor of soil fertility and sustainable agriculture at the University of Florida in Gainesville, FL. Lakesh has been farming since he was a child on his own farm. His academic school journey started in 2000. He is currently working on nutrient... Read More →

Ravinder Singh

Shinsuke Agehara

University of Florida

Wednesday September 25, 2024 8:45am - 9:00am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

9:00am HST

VCM 2 - Alternative Carbon Sources Effects on the Soil-plant Nutrient Dynamics During and Post ASD in a High Tunnel Tomato Crop System

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

South Pacific 4

Anaerobic soil disinfestation (ASD) is a microbial-driven soil disinfestation approach for the management of soilborne pests and pathogens of horticultural crops including protected vegetable production systems increasingly affected by emerging soilborne issues. ASD is implemented by incorporating in the soil an easily labile carbon (C) source, mulching the soil with an impermeable film, and irrigating the soil to field capacity. Organic amendments used as C source also provide N and other nutrients, and research is needed to assess if and how crop fertilization should be adjusted accounting for such nutrients. A study was conducted to evaluate the effect of alternative C sources on soil nutrient availability during and post-ASD in a high tunnel tomato production system. Carbon sources tested included sugarcane molasses, wheat middlings, and soybean meal mixed with wheat middlings. Each C source was applied at the standard rate of 6 Mg/ha of total C. The same C sources were also applied at half rate (3 Mg/ha of total C) balancing the total nitrogen (N) applied to 350 kg/ha of N using composted chicken manure as a source of N. The selected C source treatments were compared with untreated soil amended only with composted chicken manure and an untreated control to estimate the amount of nutrients provided by the untreated soil or by the composted chicken manure. Post ASD, fresh-market tomato cv Red Deuce was planted and used as a test crop evaluating plant growth, nutrient uptake, and yield and quality performance in response to soil treatments. Post-ASD, soil redox potential (Eh) was monitored revealing that all C sources tested determined a significant decrease of soil Eh, suggesting a good efficacy of the ASD treatment. During and post-ASD soil pH, EC, nitrate-N and ammonium-N levels were monitored using soil-water extracts (obtained with the 1:2 v:v method). Significant variation of soil pH, EC and mineral-N content were observed during and post-ASD, which influenced tomato marketable yield. Among the treatment tested WM applied at half rate and balanced for the N which had an intermediate C:N ratio (11.65) provided the highest seasonal marketable yield (10.4 kg/plant), while the untreated control amended with chicken manure provided the lowest yield. Overall, this study suggests that C application rate and the C:N ratio of the organic amendments used to apply ASD have significant effects on the efficacy of the ASD treatment as well as on the availability of nutrients and the crop performance post-ASD.

Speakers

Francesco Di Gioia

Pennsylvania State University

Co-authors

Fritzner Pierre

Pennsylvania State University

Wednesday September 25, 2024 9:00am - 9:15am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

9:15am HST

VCM 2 - Advancing Pepper Production Beyond Seasonal Limits: Findings from a High Tunnel System Integrated with Biostimulant Applications

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

South Pacific 4

Pepper is an important specialty crop in the Southwest U.S., cherished for its economic importance, cultural history, and high nutritional values. Despite being a leading pepper producer in the U.S., challenges such as high temperatures, erratic weather patterns, and imports from Mexico have hindered both production and profitability of growers in this region. In response, alternative systems like high tunnels have emerged as viable solutions. The mild winter climate in Southwest Texas offers an ideal setting for winter pepper cultivation in high tunnels, potentially boosting growers' profitability with off-season market opportunities. Application of biostimulants, such as seaweed extracts, holds promise in enhancing cold tolerance and transplant success within high tunnel systems. This study investigates the feasibility of winter pepper production in high tunnels established in the Wintergarden region, assessing various cultivars based on yield and quality. The high tunnel maintained a range of 8-10°C higher temperatures than the open-field on chilly days without additional heating. Seven pepper cultivars were evaluated, with and without seaweed extracts. Seaweed-treated plants exhibited an overall higher stomatal conductance and leaf transpiration rates along with reduced leaf electrolyte leakage. Rio de Oro; a Santa Fe type pepper had the highest PSII efficiency and total fruit yield. Seaweed application also increased total yield and individual fruit weight in cultivar-specific manner. The total phenolic content of fruits was increased by seaweed application at the early maturity stage whereas total flavonoid content varied by cultivar and maturity stage. Despite facing freeze challenges at the early transplant stage, this first-year experiment demonstrated promising potential for off-season pepper production in high tunnels in our region.

Speakers

ASMITA NAGILA

Graduate Research Assistant, Texas A&M university

Co-authors

Daniel Leskovar

Texas A

Kevin Crosby

Texas A

Wednesday September 25, 2024 9:15am - 9:30am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

9:30am HST

VCM 2 - Optimizing Nitrogen Fertilizer Rate and Planting Density of Vidalia Onion Yield and Bulb Size Distributions

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

South Pacific 4

This study was carried out at the University of Georgia (UGA) Vidalia Research Center during the 2022/2023 winter season and is being repeated in 2023/2024. The objectives of this experiment were to identify the relationship between planting density, nitrogen fertilizer rates, and the effects on yields and bulb size distribution. The variety “Sweet Magnolia” was tested at three planting densities (116,000; 87,000; and 58,000 plants per acre) and three nitrogen rates (120, 100, and 80 lbs. per acre). Results indicated there is no interaction between planting density and nitrogen rates on onion bulb size distribution or total production. However, the effect of planting density was significant. Higher densities (116,000 plants/acre) yielded a total weight of 1788 40 lbs. bags/acre with a significant proportion of jumbo-sized bulbs 62%, while lower densities (58,000 plants/acre) resulted in larger colossal bulbs 290 40 lbs. bags/acre with a reduced total yield 1370 40 lbs. bags/acre. Nitrogen application also had a significant impact on both yield and size of the bulb. The highest nitrogen rate (120 lbs./acre) produced a higher total yield (1670 40 lbs. bag/acre), with a significant portion of jumbo at 50% and colossal bulbs at 15%. There was no significant difference between the nitrogen rates of 100 and 120 lbs./acre, but the lowest nitrogen rate (80 lbs./acre) had the worst yield with 1434 40 lbs. bags/acre resulting in a 15% decreased yield compared with the higher rate. These results suggest that optimal planting density and nitrogen application are decisive for reaching the desired bulb size distribution and maximizing yield.

Speakers

Elvis Pulici

University of Georgia

Co-authors

Henry Y Sintim

University of Georgia

Juan Carlos Diaz Perez

University of Georgia

Ted McAvoy

University of Georgia

Wednesday September 25, 2024 9:30am - 9:45am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

9:45am HST

VCM 2 - Assessing the Efficacy of Plant Biostimulants on Onion Growth and Production in Greenhouse Trials and Field Conditions

Wednesday September 25, 2024 9:45am - 10:00am HST

South Pacific 4

The escalating impacts of climate change on agriculture necessitate the exploration of sustainable crop enhancement methods. This research integrates greenhouse screening and field application to evaluate the efficacy of biostimulants in promoting the growth of onion (Allium cepa L.) under variable environmental conditions. In the initial greenhouse experiment, seven biostimulants were tested, including three bacterial products (Continuum, Spectrum DS, and Tribus Original), two mycorrhizal products (Mighty Mycorrhizae and Myco Apply), one seaweed extract product (Seaweed), and one product containing humic acid (Huma Pro 16). These were applied to assess their impact on seedling emergence and growth in a peat-based soilless substrate. Huma Pro 16 and Spectrum DS were identified as the most effective in increasing seedling emergence, leaf area, and biomass. Based on these findings, field trials were conducted with four onion cultivars (red, sweet, white, and yellow), subjected to conditions simulating drought and normal watering (75 % and 100 % evapotranspiration) or with nitrogen levels adjusted to low and high (75 % and 100 % of optimal 168 kilograms per hectare). The field trials assessed bulb diameter, weight, and leaf metrics. Results indicated that cultivars responded differently to varying conditions, with red and white onions showing consistent growth patterns, while sweet onions displayed more variability. Yellow onions benefited from the biostimulants, exhibiting improved growth under both drought and low nitrogen conditions. This study demonstrates that the application of certain biostimulants can significantly enhance crop growth and resilience. Huma Pro 16 and Spectrum DS show promise for improving onion yield in the face of climatic challenges. Keywords: biostimulants, drought stress, nitrogen availability, onion, and sustainable agriculture.

Speakers

PRAKRITI NEPAL

Utah State Univeristy

Co-authors

Daniel T Drost

Utah State University

Youping Sun

Utah State University

Wednesday September 25, 2024 9:45am - 10:00am HST
South Pacific 4

Oral presentation (Individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

11:29am HST

Vegetable Crops Management 2 (VCM 2)

Wednesday September 25, 2024 11:29am - 1:20pm HST

South Pacific 3

Effect of Plastic Mulch, Living Mulches and Cover Crops on Soil Characteristics, Weed Pressure and Yield in Organic Globe Artichokes Production - Arianna Bozzolo
Effects of Off-Season Winter Cover Crops and In-Season Nematicide Application on Plant-Parasitic Nematodes - Abolfazl Hajihassani
Lessons Learned from Living Mulch Trials on Midwest Vegetable Farms - Connor Ruen
Evaluating Cover Crop Biomass and Roller Crimper Technology for Effective Weed Control in Vegetable Systems - Arianna Bozzolo
Fall Cover Crops to Follow Carrot Harvest on High Organic Matter Soils - Mary Ruth McDonald
Cover Crops For Vegetable Research Farms Need Nitrogen - Thomas Bjorkman
Insurance Industry Standards Over-estimate Yield Loss Due to Stand Reduction in Processing Sweet Corn - Charlie Rohwer
Combining Lasers and Distress Calls to Control Birds in Sweet Corn - Rebecca Brown
Pea-oat Green Manure and Reduced Nitrogen Rate Delay Maturity of Broccoli But Do Not Reduce Yield - Charlie Rohwer
Field Screening of Cabbage (Brassica oleracea var. capitata) Cultivars for Resistance to Black Rot - Manisha Kumari
Evaluation of Brassica Oleracea Genotypes in Terms of Agronomic Performance - Sotirios Tasioulas

Moderator

Manisha Kumari

Post-Doctoral Research Associate AD, The University of Georgia

Manisha Kumari is a post-doctoral research associate AD at Horticulture department, University of Georgia, Tifton campus, Tifton 31793, GA, USA.

Wednesday September 25, 2024 11:29am - 1:20pm HST
South Pacific 3

Poster Session, Vegetable Crops Management 2

SUBJECT Vegetable Crops

11:30am HST

VCM 2 - Effect of Plastic Mulch, Living Mulches and Cover Crops on Soil Characteristics, Weed Pressure and Yield in Organic Glob

Wednesday September 25, 2024 11:30am - 11:40am HST

South Pacific 3

Standard organic farming production practices for specialty crops frequently involve the use of polyethylene plastic mulch or mechanical soil disturbance to reduce weed competition and enhance crop yields. Although successful, these practices come with environmental consequences, including soil pollution and loss of soil organic matter. As such, alternative methods that prioritize the long-term health of the soil and minimize environmental impact are needed. We performed a field experiment to assess and compare the influence of five soil management systems on soil characteristics, weed pressure and yield in globe artichokes production. Artichoke (Cynara scolymus L.) seedling cvs. Tavor were established on raised beds as: A) intercropped with white clover (Trifolium repens L.) as living mulch, or B) intercropped with crimson clover (Trifolium incarnatum L.) as living mulch, or C) transplanted into mixture of buckwheat (Fagopyrum esculentum M.) and pea (Pisum sativum L.) cover crop residue or D) intercropped with Kurapia (Lippia Nodifera L.) as living mulch, or E) transplanted in PE plastic mulch. Results show that white clover increased soil organic matter (SOM), soil potassium and manganese content, water extractable carbon, soil respiration (CO2), soil nitrate, ammonium and total soil nitrogen compared to plastic mulch at 360 DAS (Days After Seeding). White clover weed suppression ability did not differ from crimson clover and buckwheat/pea mixture. Crimson clover increased SOM at preharvest sampling. Both clovers decreased artichokes yield per plant when compared to plastic mulch. Kurapia increased soil sodium content compared to plastic. Cover crop/reduce tillage system increased SOM at 120 DAS compared to plastic. Due to biomass decomposition, the suppression ability of this mixture decreased over time. Plastic mulch increased copper and iron soil concentration. Artichoke yield from plants grown on plastic mulch had comparable bud weight and yield to buckwheat/pea mixture and Kurapia. The potential to enhance soil nitrogen and carbon levels over a longer period of white clover makes it a valuable choice in systems aiming to improve soil fertility. Crimson clover emerges as the most promising among the clovers, exhibiting less competition compared to white clover, effective weed control, and, although the yield is lower than that achieved with plastic mulch, it maintains a well-balanced crop load. The reduced tillage system has shown promising results, successfully managing weeds adequately and allowing for a satisfactory level of production. No detrimental impact on yield were found intercropping artichokes with Kurapia and, but its effect on soil health was limited.

Speakers

Arianna Bozzolo

Rodale Institute

Co-authors

Andrew Smith

Rodale Institute

Jacob Pecenka

Rodale Institute

Wednesday September 25, 2024 11:30am - 11:40am HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

11:40am HST

VCM 2 - Effects of Off-Season Winter Cover Crops and In-Season Nematicide Application on Plant-Parasitic Nematodes

Wednesday September 25, 2024 11:40am - 11:50am HST

South Pacific 3

In the Southeast United States, control of parasitic nematodes in vegetable growing systems has traditionally relied on soil fumigation before planting vegetables. However, new regulations on the application of fumigant pesticides and concerns about their toxicity to non-target organisms are compelling growers to adopt sustainable alternatives. This study examined the effects of winter cover crops and subsequent production of cabbage treated with a non-fumigant nematicide on root-knot (Meloiodgyne incognita) and stubby-root (Nanidorus minor) nematodes. Off-season treatments consisted of oilseed radish cvs. “Control” and “Image”, cereal rye cv. “Wrerens Abrussi”, oat cv. “Tachiibuki”, black oat cv. “Protex” and mustard cv. “Caliente”. In-season treatments consisted of an untreated check and the nematicide fluensulfone, applied through the drip irrigation system one week before transplanting cabbage into raised beds covered with plastic mulch. A weedy fallow treatment was also included for comparison. After growing cover crops and incorporating plant residues into the soil, M. incognita population density was significantly reduced only in plots where Tachiibuki oat was grown. None of the cover crops reduced the population density of N. minor. Nematicide application on cabbage significantly reduced M. incognita populations in plots previously grown with Tachiibuki and Pratex oats, and mustard compared to the untreated check. Similarly, the nematicide reduced the N. minor population density in plots previously grown with oats, mustard, and rye. The efficacy of fluensulfone on root gall severity of cabbage was significant only in the untreated check, with plots previously grown with Image radish having a significantly lower root galling than the mustard, rye, and weedy fallow. Nematicide application reduced root gall severity of cabbage in plots previously grown with radish, Tachiibuki oat, and rye compared to the untreated check. Growing cabbage after cover crops and using the nematicide did not impact cabbage yield compared to the untreated check. These results indicate that cover cropping with Tachiibuki oat and the use of non-fumigant nematicides appear to be effective for managing these nematode species.

Speakers

Abolfazl Hajihassani

University of Florida

Wednesday September 25, 2024 11:40am - 11:50am HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

11:50am HST

VCM 2 - Lessons Learned from Living Mulch Trials on Midwest Vegetable Farms

Wednesday September 25, 2024 11:50am - 12:00pm HST

South Pacific 3

In the Great Plains region of the United States, perennial clover living mulch is being explored for the potential benefits of reducing tillage, suppressing weeds, and supplementing soil. Perennial living mulch systems also have the potential to reduce the use of single-use plastic. Research on the use of perennial living mulch in vegetable systems has been limited in the Great Plans, and farmers have expressed interest in trialing this system to improve soil health and reduce erosion by wind and rain. Two vegetable farms, Haroldson Farms in Bruce, SD and Blue Sky Vegetable Company in Worthing, SD, have participated in the on-farm trials since 2023. In collaboration with South Dakota State University, the on-farm trial collaborators were interested in using living mulch to control weeds and reduce the need for plastic. ‘Domino’ white clover (WC) (Trifolium repens), and ‘Dynamite’ red clover (RC) (Trifolium pratense) are the clovers that were selected for the on-farm trials. The clover struggled to grow with the lack of rainfall and was soon overtaken by weeds. Results quickly showed that the lack of moisture had a detrimental effect on the clover’s ability to compete and establish in walkways. A mixture of grasses and broadleaf were observed as the clover declined. Early moisture is essential for the establishment of clover living mulch and be used to its full potential. The planting method of frost seeding would be recommended for future trials to encourage clover germination and establishment before weeds get large enough to compete.

Speakers

Connor Ruen

South Dakota State University

Co-authors

Kristine Lang

South Dakota State University

Thandiwe Nleya

South Dakota State University

Wednesday September 25, 2024 11:50am - 12:00pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:00pm HST

VCM 2 - Evaluating Cover Crop Biomass and Roller Crimper Technology for Effective Weed Control in Vegetable Systems

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

South Pacific 3

This study aims to evaluate the efficacy of roller crimper technology in tandem with various cover crop mixtures for weed management in coastal California's vegetable systems. The experiment was conducted at the Rodale Institute California Organic Center (34.220453, -199.108214) in Camarillo, CA. Twenty randomized plots 46 x 12 m were measured and assigned to either to a bare soil treatment or one of two cover crop mixes: oat (Avena sativa) hairy vetch (Vicia villosa), or oat pea (Pisum sativum), with cover crops terminated via conventional tillage using a disk (T) or using a roller crimper for no-till system (NT). Pumpkins (Howden variety) were direct seeded, and data on cover crop growth and weed pressure were collected at three time points: before cover crop termination, after cover crop termination and after harvest. At harvest, a subset of each plot was sampled to count and weigh pumpkins for crop yield assessment. Before termination, the total dry matter of cover crop biomass showed no significant differences between oat/peas and oat/vetch mixes. Oat/vetch exhibited lower weed biomass at 0.74 t/ha compared to oat/peas at 1.98 t/ha (0.8 t/a); bare soil plots had the greatest biomass at 21.35 t/ha. After termination (30 DAT), NT plots showed similar biomass production between oat/peas and oat/vetch. T plots displayed residues on the soil surface, with higher amounts in oat/vetch at 8.7 t/ha compared to oat/peas at 8.4 t/ha. Weed emergence after cover crop termination was comparable across all plots with cover crops, ranging from 1.24 t/ha to 2.22 t/ha, while bare soil exhibited higher weed biomass at 10 t/ha compared to plots with cover crops. After harvest (120 DAT), oat/vetch in NT plots showed greater biomass retention compared to T plots, as did oat/peas in NT plots. All plots experienced biomass reductions, with oat/peas T plots experiencing the most significant decrease at 61.5%. Oat/vetch mixture plots (T and NT) and bare soil had similar pumpkins production per hectare, outperforming oat/pea T plots in terms of fruit number and production per hectare. Oat/pea T plots exhibited decreased fruit weight compared to bare soil.

Speakers

Arianna Bozzolo

Rodale Institute

Co-authors

Andrew Smith

Rodale Institute

Jacob Pecenka

Rodale Institute

Wednesday September 25, 2024 12:00pm - 12:10pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:10pm HST

VCM 2 - Fall Cover Crops to Follow Carrot Harvest on High Organic Matter Soils

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

South Pacific 3

The high organic matter (muck) soils in the Holland Marsh, Ontario, Canada, are prone to wind erosion, especially in the fall and winter months. Good canopy coverage of ideally 30%, is important for protecting the soil and reducing soil erosion. Carrots are usually harvested in October. Cool temperatures at this time result in slow germination and growth of cover crop species. Field trials were conducted to assess the efficacy of various cover crops and methods for rapid establishment after carrot harvest. One approach to increasing germination and emergence is seed priming. Seeds of barley, oats, and triticale were primed by soaking for 24 hr in water (hydro-priming) or potassium nitrate at 5 mg L-1 (osmo-priming). Seed was dried for 24 hours and then seeded into pots placed in controlled environments at 5, 10 or 21°C. Priming generally resulted in faster germination and higher biomass especially at lower temperatures of 5 and 10°C. Primed and non-primed seed was seeded into high organic matter soil (50% organic matter, pH 6.9) on 17 Oct. and crop growth was assessed on 13 Nov. There were no advantages of priming in the field trials. Non-primed barley had high or higher canopy coverage (13%), plant counts and dry weight, compared to other species and primed seed. Barely was also grown as transplants with 2 seeds/plug and transplanted in the trial on 17 Oct. This treatment had higher canopy coverage (25%) and dry weight than seeded treatments. However, using barley transplants is not a cost effective option at this time. In a separate trial on an adjacent site, barley was over-seeded into standing carrots on 27 Sept. at 200 kg ha-1, and the carrots were harvested on 17 Oct. Barley and fall rye were direct seeded on 17 Oct. Pre-harvest seeding of barley resulted in significantly better establishment, canopy coverage and biomass, although all were low, maximum 12% coverage. There was a strong positive correlation between canopy coverage and biomass production across all trials. More research is needed on cover crops species and establishment methods.

Speakers

Mary Ruth McDonald

University of Guelph

Co-authors

Kimberly Schneider

University of Guelph

Neem Pandey

University of Guelph

Wednesday September 25, 2024 12:10pm - 12:20pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:20pm HST

VCM 2 - Cover Crops For Vegetable Research Farms Need Nitrogen

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

South Pacific 3

On research farms on which vegetable crops are studied, there is often a need to aggressively maintain and improve soil health, while also keeping fields ready to be assigned to research projects. We tested a protocol for keeping a Northeast farm in an appropriate condition by alternating a winter cover crop of cereal rye and a summer cover crop of forage sorghum-sudangrass with no tillage. The alternating cycle was flexible for entry points when vegetable researchers finished with an experiment, as well as for exit points to make the ground ready for an experiment. Rye was sown in late September in Geneva, NY with a no-till drill and allowed to grow to anthesis in May. Sorghum-sudangrass was sown in mid-June with the no-till drill. We tested how much nitrogen fertilizer was needed to obtain a desirable amount of growth (3 tons/acre dry mater) in the sorghum- sudangrass. The trial was done in four fields using 0, 20, 40 and 60 lb N broadcast on the rye residue at planting. The highest rate is as much as our farm would agree to invest in a cover crop, but also below forage-crop recommendations. The biomass when growth stopped due to cold (Sept 18) responded strongly to nitrogen. Without nitrogen, the biomass was only 0.5 T/ac. At 60 lb/ac, the biomass ranged among fields from 2 to 4 T/ac. Nitrogen limitation was also assessed using a SPAD chlorophyll meter. The leaves in the 0, 20 and 40 lb/ac were yellow (SPAD 22-28), with the top N rate notably greener (SPAD 30-35). The fully green control had a SPAD value of 40. The cover crop rotation kept the field in a condition where is could be prepared to being a research project with about a month’s advance notice. However, to get sufficient growth of the summer cover crop, additional nitrogen is needed. This farm is on a high-fertility silt loam, but with low organic matter from repeated research trials. In that situation, at least 60 lb/ac of actual N is needed for the cover crops to meet biomass expectations.

Speakers

Thomas Bjorkman

Professor, CALS Horticulture

Wednesday September 25, 2024 12:20pm - 12:30pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:30pm HST

VCM 2 - Insurance Industry Standards Over-estimate Yield Loss Due to Stand Reduction in Processing Sweet Corn

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

South Pacific 3

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 assessments is determining yield loss due to complete plant loss. To that end, we compared ear yield of sweet corn thinned to 75, 50, or 25% of a full population at three times throughout the growing season to control plots that were not thinned. We repeated this in three consecutive years at two locations, without irrigation or supplemental fertilizer. Average yield for control plots was 16.4–20.3 Mg•ha-1. Average yield losses due to thinning were generally less than currently-used actuarial estimates. For example, average yield of sweet corn when thinned to 50% of a full population at growth stage V3–V5 was 88–96% (95%CI) of full yield. The actuarial estimate is 78% of full yield, indicating greater resilience than expected. The number of tillers per plant was greater in all thinned plots, especially those thinned early in the season. Kernel recovery was unaffected by thinning treatment in one location and declined slightly at heavy thinning in the other location. Sweet corn actuarial tables should be different from actuarial tables based on field corn.

Speakers

Charlie Rohwer

Scientist, University of Minnesota

Co-authors

Joe Lauer

University of Wisconsin-Madison

Mark Zarnstorff

National Crop Insurance Services

Wednesday September 25, 2024 12:30pm - 12:40pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:40pm HST

VCM 2 - Combining Lasers and Distress Calls to Control Birds in Sweet Corn

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

South Pacific 3

Red-winged blackbirds (Agelaius phoeniceus) and European starlings (Sturnus vulgaris) cause significant damage to sweet corn (Zea mays). Even minor damage can render ears unmarketable and the need to sort out damaged ears during packing increases costs for growers. Propane cannons and pyrotechnics have long been the preferred methods for preventing birds from damaging corn, but both methods create noise pollution and conflicts with farm neighbors. Automated laser scarecrows and automated recordings of bird distress and predator calls are two newer technologies for deterring birds from crops. We tested both technologies on a research farm in Kingston, Rhode Island and in commercial processing sweet corn fields in western New York in 2022 and 2023. All experiments used naturally occurring flocks of wild birds; flock size and species makeup varied between fields and over time. The automated laser scarecrows (LS) were designed and built by the URI Laser Scarecrow Project; they utilized a 50 mW 532 nm green laser with a beam diameter of 14 mm at the aperture and a dispersion of 4 mrad. Vertical and horizontal movement of the beam was randomized by a microcontroller. Bird Gard Super Pro units (BG) randomly played digital recordings of distress and alarm calls of red-winged blackbirds and European starlings and hunting calls of hawks and falcons. Data were collected as counts of damaged ears and converted to percentage of total ears for analysis. In Rhode Island the effect of laser scarecrow alone was compared to the effect of the laser scarecrow combined with the bird distress calls. In New York the two deterrent treatments were also compared to an unprotected control. In Rhode Island in 2022 bird damage averaged 20.7% with just LS and 7.1% with LS BG; the difference was significant at P

Speakers

Rebecca Brown

Co-authors

Julie Kikkert

Cornell Cooperative Extension

Wednesday September 25, 2024 12:40pm - 12:50pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

12:50pm HST

VCM 2 - Pea-oat Green Manure and Reduced Nitrogen Rate Delay Maturity of Broccoli But Do Not Reduce Yield

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

South Pacific 3

Cover crop biomass can provide nitrogen (N) to a sequential cash crop as a ‘green manure’, whether the N is sourced from the atmosphere or from the soil. For short-season vegetable crops in Minnesota, like transplanted broccoli, there is time for a cover crop to be grown before or after the main crop. Growing a pea-oat cover crop early in the spring, before broccoli, may increase the N available to the broccoli. However, immobilization of green manure N may reduce N availability at a time of high N demand in broccoli. In order to study N availability to broccoli provided by a spring-planted pea-oat cover crop mix, four reduced-rate nitrogen treatments were applied to two broccoli hybrids (‘Green Magic’ or ‘Gypsy’) after a spring-planted pea-oat cover crop was incorporated. Yield and maturity of broccoli were compared to broccoli grown without green manure and given a full nitrogen rate (170 kg N / ha). The fertilizer treatments included slow-release urea (139 or 110 kg N / ha), composted poultry litter with blood meal at ~110 kg N available / ha, and turkey manure applied with blood meal in the autumn before growing green manure and broccoli (~110 kg N available / ha). There was no reduction in total yield (7900 kg / ha) or marketability (>95%), but maturity was delayed by ~2 days for most treatments. A microbial inoculant (Nature’s Source®) applied to the soil at planting did not have a measurable impact on any response.

Speakers

Charlie Rohwer

Scientist, University of Minnesota

Wednesday September 25, 2024 12:50pm - 1:00pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

1:00pm HST

VCM 2 - Field Screening of Cabbage (Brassica oleracea var. capitata) Cultivars for Resistance to Black Rot

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

South Pacific 3

One of the most effective management strategies for controlling black rot (Xanthomonas campestris pv. Campestris (Xcc)) in cabbage (Brassica oleracea var. capitata) is resistant cultivars. The objectives of this research were to evaluate commercial and experimental cabbage cultivars for black rot resistance and determine yield potential, harvest maturity, and head quality. A field experiment with nine cultivars (1488, Capture, Celebrate, Cheers, Expat, Melissa, TCA-576, TCA-606, and TCA-607) was carried out during the fall season of 2023 at Hort Hill research farm on the University of Georgia, Tifton campus. ‘Cheers’ (commonly grown high-yielding cultivar), ‘Capture’, and ‘Expat’ (claims high resistance to black rot), and ‘Melissa’ (black rot susceptible Savoy cabbage) were used as checks for comparison with other F1 cabbages. Plants were spray-inoculated with Xcc (250 ml of 10^6 CFU/ml) at 5 and 7 weeks after transplanting. Treatments were arranged in a randomized complete block design with four replications. Relevant agronomic practices, such as irrigation, fertilization, and insect management, were implemented uniformly across all plots. Black rot severity was rated using a 1-9 scale, where 1 indicates the most resistant and 9 represents the least resistant (most susceptible) cultivar. The trial was harvested four times on the following dates:11/30/2023, 12/12/2023, 12/20/2023, and 01/03/2023. Black rot severity, total head counts and weights; and average head weight and height: and average core height, and width were statistically significant between treatments. ‘TCA-607’ and ‘Capture’ had the highest resistance to black rot disease, while ‘1488’ was the most susceptible. All other cultivars expressed moderate levels of resistance. In the first harvest ‘Cheers’ and ‘TCA-607’ had the highest total marketable head counts and weights, indicating early maturity. In addition, ‘Cheers’ and ‘TCA-607’ cabbage had the highest total marketable head counts and weight, followed closely by ‘TCA-606, ‘Celebrate’, and ‘1488’. ‘Cheers’ and ‘TCA-607’ had the highest average head height. Furthermore ‘TCA-607’ outperformed all the cultivars for the average head weight. Among all the cultivars ‘Melissa’ and ‘Expat’ performed the worst for total marketable counts and weights. Overall based on our trial, the experimental cultivar ‘TCA-607’ has the best combination of traits: best black rot resistance, highest yields, and biggest heads.

Speakers

Manisha Kumari

Post-Doctoral Research Associate AD, The University of Georgia

Manisha Kumari is a post-doctoral research associate AD at Horticulture department, University of Georgia, Tifton campus, Tifton 31793, GA, USA.

Co-authors

Ted McAvoy

University of Georgia

Wednesday September 25, 2024 1:00pm - 1:10pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

1:10pm HST

VCM 2 - Evaluation of Brassica Oleracea Genotypes in Terms of Agronomic Performance

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

South Pacific 3

Plant growth performance of 35 different broccoli cultivars was assessed during the Fall season 2023 in terms of plant growth and head development in SW Florida. In particular, seeds of Brassica oleracea var. italica genotypes that were obtained from USDA, ARS, Plant Genetic Resources Unit (PGRU)

Speakers

Sotirios Tasioulas

SWFREC - University of Florida/IFAS

Co-authors

Jessie Watson

SWFREC - University of Florida/IFAS

Pavlos Tsouvaltzis

Southwest Florida Research and Education Center, University of Florida

Tie Liu

University of Florida

Wednesday September 25, 2024 1:10pm - 1:20pm HST
South Pacific 3

Poster presentation (individual talk), Vegetable Crops Management 2

SUBJECT Vegetable Crops

1:20pm HST

VCM 2 - Evaluation of Vegetable Soybean Adaptations to South Florida’s Tropical Climate

Wednesday September 25, 2024 1:20pm - 1:35pm HST

South Pacific 3

Vegetable soybean, also known as edamame, is a specialty crop harvested at an immature stage and consumed as pods. It has become increasingly popular in the United States due to its high nutritional value and good taste. Currently, most edamame consumed in the U.S. is imported as a frozen product. States such as Arkansas and Kentucky have started to grow this crop locally on a small scale to meet the high demand. South Florida, known for producing fresh vegetables sold nationwide, especially in the winter and spring markets, also has a highly diverse and growing ethnic population with significant local market potential. These factors make growers in South Florida highly interested in cultivating edamame to meet the demand in both national and local markets. Sixteen commercial edamame varieties were selected and assessed for differences in phenotypic performance, including emergence, yield, plant height, plant width, 10-pod weight, and pod size, to evaluate their production potential in South Florida. Varieties showed significant effects on most traits studied. Emergence rates ranged from 0 to 85%, and fresh pod yield ranged from 4.41 to 14.34 t/ha among all 16 varieties. Varieties like Goo, Karikachi #3, and Midori Giant, despite having moderate emergence rates, produced higher fresh pod yields due to their larger plants, resulting in bigger pods. There were variations in average pod length (35.61 – 51.21 mm), width (9 - 14 mm), and thickness (5.46 - 8.74 mm) among the varieties, with Goo standing out significantly in size. Overall, Goo, Karikachi #3, and Midori Giant demonstrated particularly favorable yield and good pod quality, showing potential for commercial edamame production in South Florida. This research highlighted the potential to grow edamame in higher hardness zone, providing foundational knowledge on edamame production in the US.

Speakers

Xiaoying Li

University of Florida, IFAS

Co-authors

Vander Lacerda

You's Kertye Myrtil

Wednesday September 25, 2024 1:20pm - 1:35pm HST
South Pacific 3

Poster presentation (individual talk)

SUBJECT Vegetable Crops

1:29pm HST

Vegetable Crops Management 3 (VCM 3)

Wednesday September 25, 2024 1:29pm - 3:30pm HST

Kahili

Monitoring High Tunnel Soil Temperature Fluxes to Understand Soil Health Implications - Bret Lang
Performance of Semi-Controlled Protective Net House at Farmers’ Field to Make The Year-Round Availability of Quality Vegetables and Higher Benefit Cost - AKM Quamruzzaman
Evaluating The Effect Of Cultivar On Garlic Growth And Yield - Stephen Mensah
Optimizing Butterhead Lettuce Production in a High Tunnel Environment - Alan Walters
Resource Use Efficiency, Yield, and Quality of Amaranth Grown as a Summer Leafy Green in Alternative Soilless Systems - Pradip Poudel
Improving Seed Germination, Seedling Biomass and Drought Tolerance of Microgreens Using Low-temperature Plasma - S Mentreddy
Differential performance of Radicchio cultivars in New Hampshire - Becky Sideman
Comparative Analysis of Biodegradable Mulch Use in Hill-side Strawberry Production - Amrita Mukherjee

Moderator

Stephen Mensah

Graduate Research Assistant, North Dakota State University

Greetings! I'm Stephen Mensah, proud son of Ghana. My journey began with a Bachelor's degree in Agriculture from the esteemed University of Cape Coast, Ghana. Now, I'm embarking on an exciting chapter as a graduate student at North Dakota State University, passionately pursuing a... Read More →

Wednesday September 25, 2024 1:29pm - 3:30pm HST
Kahili

Oral Sessions, Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:30pm HST

VCM 3 - Monitoring High Tunnel Soil Temperature Fluxes to Understand Soil Health Implications

Wednesday September 25, 2024 1:30pm - 1:45pm HST

Kahili

High tunnel soil health is crucial for successful and sustainable crop production within protected environments. Soil microbial activity is highly temperature-dependent, and soils that are slightly warmer will foster increased metabolic rates within soil communities enhancing microbial diversity and enzymatic activity, promoting nutrient availability. However, little is understood about the potential for microbial activity during colder seasons in norther latitudes when high tunnels are taken out of production and soils are left fallow. Temperature variation in high tunnels could also create variation in microbial community activity, creating spatial nutrient variation with impacts on production the following season. To analyze soil temperature fluxes, we buried an array of 27 soil sensors four inches deep within the soil in a newly built, 30-foot-wideby 96-foot-long tunnel located in Brookings, South Dakota. The high tunnel was oriented east to west and soil was bare. Soil temperatures were recorded at 30-minute intervals from December 22 to March 15, (2023 – 2024). Air temperature and light (lux) data was also collected inside of the high tunnel as well as external weather data from a nearby (>1km) Mesonet weather station. We used multiple linear regression to model the relationship between average internal soil temperature and internal light and temperature data. We also compared sensor location (latitude, longitude, and Euclidean distance from the center of the high tunnel) on soil temperature within the high tunnel using an ANOVA and multiple linear regression to examine how sensor location was related to soil temperature. Our top model of internal soil temperature showed light, internal temperature, and the interaction between light and internal temperature explained a large amount of high tunnel soil temperature variation (R2 = 0.87, p < 0.0001). There was also significant variation in soil temperature throughout the high tunnel, with the daily mean difference of 3.12 degrees Celsius (p < 0.0001) observed between our sensor at the center of the high tunnel and our sensor near the northwest corner of the high tunnel. Our top model showed that latitude, the quadratic of longitude, and the Euclidean distance from the center of the high tunnel explained a moderate amount of high tunnel soil temperature variation (R2 = 0.44, p < 0.0001). This analysis demonstrates a need to further investigate how microbial communities react to temperature variation within high tunnels when they are not in production.

Speakers

Bret Lang

Student, South Dakota State University

Co-authors

Kristine Lang

South Dakota State University

Lora Perkins

South Dakota State University

Wednesday September 25, 2024 1:30pm - 1:45pm HST
Kahili

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:45pm HST

VCM 3 - Performance of Semi-Controlled Protective Net House at Farmers’ Field to Make The Year-Round Availability of Quality Vegetables and Higher Benefit Cost

Wednesday September 25, 2024 1:45pm - 2:00pm HST

Kahili

The study was conducted at two farmers’ fields in Bangladesh viz., Shibpur, Narshingdi (24.050º N Latitude and 90.718º E) and Chowara Bazar, Cumilla (23.408º N Latitude and 91.244º E), during Oct 2021 to Sep 2022. In this study, we evaluated the effects of five types of vegetables, viz., tomato, sweet pepper, cucumber, netted melon, and okra, under a protected polynet house. The cultivation of vegetables in protected conditions using transparent UV poly net houses played a better role in improving quality, advancing maturity, fruit size, and yield and reducing pest and disease infestation. Protected polynet houses allow better utilization of sunlight due to the manipulation of the spectra of radiation reaching the crops, thus promoting physiological responses in plant and fruit development, including leaf area index, chlorophyll and carotenoid content, tissue structure, fruit ripening, and physiological disorders. Under this evaluation, cultivation under UV Poly nethouse was found better in the Cumilla area compared to Narshingdi. There might be differences in management operations by different growers. For all crops, viz., tomato, sweet pepper, cucumber, netted melon, and okra, the production of the Cumilla area was very significant and higher. The Benefit-cost ratio was also higher [Tomato (2.05), sweet pepper (2.53), cucumber (1.42), netted melon (2.63) and okra (1.35) in Cumilla compared to Narshingdi [Tomato (1.75), sweet pepper (1.92), cucumber (1.21), netted melon (2.20), okra (1.22)], the lower BCR is due to the 1st year calculation. So, with UV poly nethouse technology, high value thermos-sensitive vegetables can be commercially grown year-round successfully to produce a safe and quality product, while higher fruit yield/unit area will be achieved in a protected nethouse than in a field.

Speakers

Dr. AKM Quamruzzaman

Chief Scientific Officer, Bangladesh Agricultural Research Institute

Dr. AKM Quamruzzaman is serving at the Olericulture Division, Horticulture Research Centre, Bangladesh Agriculture Research Institute, Bangladesh as Chief Scientific Officer. He joined BARI in 1995 as Scientific Officer. As a horticulturist, now he is the Chief breeder of Solanaceous... Read More →

Co-authors

Ferdouse Islam

Bangladesh Agricultural Research Institute

Limu Akter

Bangladesh Agricultural Research Institute

Wednesday September 25, 2024 1:45pm - 2:00pm HST
Kahili

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

2:00pm HST

VCM 3 - Evaluating The Effect Of Cultivar On Garlic Growth And Yield

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

Kahili

Assessing the impact of cultivar on garlic growth and yield ensures satisfactory productivity and better management of genetic resources for growers in North Dakota. A field experiment was conducted at the NDSU Horticulture Research Farm, located near Absaraka, ND to evaluate the effect of cultivar on the growth and yield of garlic. Twenty-nine garlic cultivars were arranged in a randomized complete block design (RCBD) with 4 replications. The leaf number, bulb diameter, bulb weight, scape weight and length were recorded throughout the growing season. The results showed significant differences between cultivars for all the variables evaluated. The highest bulb diameter(60.5 cm) was recorded in ‘German White’, while the lowest diameter (38.9 cm) was recorded in ‘German Red’. The highest bulb weight(73.4 g) was with ‘German White’ while ‘Italian Loiacono’ resulted in the lowest bulb weight(21.2 g).The number of leaves was recorded at 30, 45, 60, and 80 days after sprouting (DAS). The average number of leaves was similar for all cultivars until 60 DAS when ‘Ukrainian Red’ had the highest number of leaves (11) and ‘German Red’ had the fewest leaves (7). ‘Dakota White’ produced the longest scapes while ‘Italian Loiacono’ and ‘White Spring’ did not produce any scapes. ‘German White’ recorded the heaviest scapes (13.8 g). In conclusion garlic cultivar affected the growth and yield when grown under North Dakota environmental conditions. ‘German White’ appeared to be the most adapted to North Dakota environmental conditions while ‘Italian Loiacono’ and ‘German Red’ were the least adapted.

Speakers

Stephen Mensah

Graduate Research Assistant, North Dakota State University

Co-authors

Harlene HattermanValenti

NDSU

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

2:00pm HST

Fruit, Vegetable, and Edible Crops Collaboration Session

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

Coral 4

A forum for discussion of potential collaborations with regards to fruit, vegetable, and edible crops – i.e. citrus, breeding, production systems, postharvest, pomology, crop management, viticulture, etc.

Wednesday September 25, 2024 2:00pm - 3:00pm HST
Coral 4

Hort Theater & Collaboration Center

SUBJECT Citrus, Postharvest, Pomology, Viticulture, Vegetable Crops, Local Food Systems, Professional Development/Career

2:15pm HST

VCM 3 - Optimizing Butterhead Lettuce Production in a High Tunnel Environment

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

Kahili

The production of fast-growing vegetable crops (such as specialty type lettuces) in slightly modified environments using high tunnels are widely underutilized. These structures can be used in the Midwest for winter production of a wide variety of leafy greens, including specialty lettuce. These crops have potential to garner a market premium due to high demand when there are not many other local vegetables for sale. Therefore, a study was conducted in 2020 and 2021 to evaluate four butterhead lettuce varieties (‘Nancy’, ‘Rhapsody’, ‘Red Cross’ and ‘Skyphos’) to determine optimal density for maximum revenue generation on a 3 ft wide raised bed. Three rows per bed and at 9 in. between plants worked best for ‘Nancy’, ‘Rhapsody’ and ‘Skyphos’, while for ‘Red Cross’ (a small more erect growing variety), 4 rows per bed at 12-inch spacing between plants maximized productivity. Head diameters were also highest for ‘Nancy’, ‘Rhapsody’ and ‘Skyphos’ using the 3 row, 12 inch between plant spacings. Overall gross revenues obtained per high tunnel, depending on plant density and variety, ranged from $3,600 to $6,000 (sold per piece at $4 each) or $1,753 to $7,279 (sold by weight at $6/ lb) for a typical 26’ (wide) x 48’ (long) high tunnel. Although most revenues increased when sold by weight, some increased by 50% (e.g., Rhapsody when grown at 3 row and 12 in spacings). Additionally, ‘Nancy’ (green-leaf type) and ‘Skyphos’ (red-leaf type) tended to be of higher quality than the other varieties evaluated and would be the better varieties to grow in a lower Midwest high tunnel environment. Both ‘Nancy’ and ‘Skyphos’ had optimal gross revenues when grown at 3 rows per bed with 9 in-row spacings when sold by piece ($4,500) or weight ($6,979 and $6,426, respectively). Thus, it is important for growers to understand the importance of butterhead variety selection and plant density in a high tunnel, as well as the method sold to maximizes revenues.

Speakers

Alan Walters

Southern Illinois University

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

2:30pm HST

VCM 3 - Resource Use Efficiency, Yield, and Quality of Amaranth Grown as a Summer Leafy Green in Alternative Soilless Systems

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

Kahili

Soilless growing systems (SGS) integrated into controlled environment agriculture (CEA) offer a viable solution for increasing food production in densely populated areas with limited land, water, and nutritional security. The design, components, inputs, and nutrient management of alternative SGS along with the plant genotype, directly impact crop yield, nutritional value, and resource use efficiency. As the adoption of CEA and SGS continues to expand, there is a growing need to compare and evaluate the performance of alternative SGS in terms of resource use efficiency, crop yield, and impact on crop nutritional quality. To this purpose, a study was undertaken to assess the performance of five alternative SGSs including Deep Water Culture (DWC), Nutrient Film Techniques (NFT), Ebb and Flow, Drip irrigation, and the Kratky system concerning yield, nutritional quality, and resource use efficiency, using green and red stripe amaranth cultivar as test crops. As expected, the Kratky system had the lowest dissolved oxygen levels in the nutrient solution compared to other SGSs. Among the growing systems, DWC and NFT exhibited higher fresh and dry biomass production compared to drip irrigation, ebb and flow, and the Kratky system. There was no distinct difference in leaf fresh and dry weight between cultivars, but green amaranth displayed higher stem fresh and dry weight than red stripe amaranth. Dry matter content remained unaffected by the SGS, while red stripe amaranth exhibited higher dry matter content compared to green amaranth. The Kratky and DWC systems utilized 34.2% and 25.6% less nutrient solution, respectively, compared to the ebb and flow system, which had the highest nutrient solution consumption compared to other methods. DWC had the highest water use efficiency (WUE, dry biomass produced per liter of water used). Nitrate content in amaranth leaves was higher when grown in NFT compared to drip irrigation, DWC, and ebb and flow, but was similar to Kratky. The red stripe cultivar displayed higher nitrate content than the green one. Regarding bioactive compounds, green amaranth exhibited higher total antioxidants and flavonoids, whereas DWC and NFT led to lower total phenols and flavonoids compared to the Kratky, ebb and flow, and drip irrigation systems. In conclusion, the DWC and NFT systems maximized yield, with DWC having higher water use efficiency, while Kratky, ebb and flow, and drip irrigation system resulted in higher nutritional quality of the amaranth grown as a summer leafy vegetable.

Speakers

Pradip Poudel

The Penn State University

Pradip

Co-authors

Francesco Di Gioia

The Pennsylvania State University

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

2:45pm HST

VCM 3 - Improving Seed Germination, Seedling Biomass and Drought Tolerance of Microgreens Using Low-temperature Plasma

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

Kahili

Microgreens, harvested within 7-21 days, are nutritionally dense and are rich sources of antioxidants, minerals, and vitamins required for body and mental health. However, poor germination, leading to poor establishment, seed-borne diseases, and high water consumption often limit microgreen production. Low-temperature plasma (LTP) is a partially ionized gas with unbound electrons, neutral particles, ions, reactive nitrogen and oxygen species, and ultraviolet light. LTP is emerging as a viable non-chemical tool for seed priming, improving crop productivity, and disinfecting seeds and foods, among other uses. Thus, LTP may address the concerns limiting microgreen production. The effects of LTP on imbibition, germination rate of germination, seedling biomass, and drought tolerance were assessed primarily using mustard greens and ten microgreen crops with or without Ar or He Plasma at different exposure times. The drought tolerance experiment induced drought stress using PEG 6000 at 0 (Control), 5, 10, and 15% at w/v. The treated or untreated seeds were placed in Petri dishes and later transplanted into pots containing soilless potting mix. The days to first seed germination, germination rate, seedling height, root length, seedling and root biomass were recorded. Ar and He LTP hastened seed germination and increased the total seed germination percentage over Control. Ar and He LTP enhanced seed germination by 12.7% and 5.6%, respectively. He LTP increased seedling length by 40% and doubled the seedling fresh biomass over the Control. Ar LTP at 30 s and He at 90 s increased the root length by nearly 17% and 71% over that of Control, respectively. In another study, seeds directly exposed to either LTP or plasma-activated water (PAW) showed a 36% increase in seed germination compared to Control. Plant height significantly increased by 98% in Ar30 seconds and 50% (all other treatments) compared to Control. Exposure of seeds directly to He and Ar plasma also increased seedling biomass. He30s, He 60s, He 90s, and Ar 90s significantly enhanced biomass by 250%, 200%, 215%, and 120%, respectively compared to Control. In another study, seeds of ten microgreen crops exposed to Ar LTP for 30 seconds or He LTP for 90 seconds significantly boosted imbibition and germination rates compared to untreated seeds within 24 hours of treatment. The study showed that Ar or He LTP could improve the drought tolerance of microgreens by shortening the crop growing cycle and increasing root length without compromising seedling biomass.

Speakers

S Mentreddy

Alabama A

Dr. Srinivasa Rao Mentreddy, an Indian-born American citizen, is a Professor of crop science at Alabama A

Co-authors

Sravan Kumar Sanathanam

Alabama A

Trang Pham

Alabama A

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

3:00pm HST

VCM 3 - Differential performance of Radicchio cultivars in New Hampshire

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

Kahili

Radicchio (Cichorium intybus var. latifolium) is grown widely throughout Europe, especially northern Italy. This crop features several groups that differ in color, shape, and culinary use, and there is considerable phenotypic variation among and within groups and cultivars. The New England growing climate is very different from that of major production regions in Europe and the pacific northwestern U.S. The availability of varieties to commercial growers in the U.S. has expanded greatly, but there remains a need for regionally relevant information about performance of these varieties. In Durham, NH, USA we grew 30 (2022) and 34 (2023) cultivars of radicchio belonging to seven main groups (Chioggia, Castelfranco, Treviso, Sugarloaf, Verona, Rosa del Veneto, and Lusia). In both years, they were seeded on 20-21 June, and transplanted on 14-15 July. Plants were harvested and weighed as they reached market maturity, or considered unmarketable due to bolting, rot, tipburn, or failure to head. We used standard cultural practices for the region: plants were grown in double rows on 30-inch-wide raised beds covered with white-on-black plastic mulch with drip irrigation. The weather in 2022 and 2023 differed greatly, with 2022 experiencing warm and dry conditions, and 2023 much wetter and cooler. The percentage of heads that became marketable ranged from 0-94% in 2022, and from 10-95% in 2023. Several cultivars had very high percentages of unmarketable heads, due to tipburn, rot, bolting, or failure to head. We also observed cultivar differences in susceptibility to powdery mildew. In both years, the cv. Rubro developed powdery mildew early and developed severe symptoms, several others eventually developed symptoms, and some never did. For traditional round red Chioggia types, several cultivars had very high percentages of marketable heads, and appear to be well adapted to production in the northeast. We identified cultivars within both sugarloaf and Treviso types that were well adapted, with high percentages of marketable heads. The cultivars we evaluated within the Lusia and Rosa del Veneto types were especially interesting from a culinary and attractiveness point of view, but had high percentages of rot (Lusia types) and very long days to maturity required (Rosa del Veneto types).

Speakers

Becky Sideman

Member-At-Large

Co-authors

Lilly Hartman

University of New Hampshire

Mark Hutton

University of Maine

Peyton Ginakes

University of Maine

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

3:15pm HST

VCM 3 - Comparative Analysis of Biodegradable Mulch Use in Hill-side Strawberry Production

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

Kahili

Comparative analysis of biodegradable mulch use in hill-side strawberry production Plastic film (PF) is widely used in crop production, yet global environmental concerns urge for reduced plastic waste. Biodegradable and bio-based mulches emerge as promising alternatives, potentially crucial for sustainable agriculture. This significance is emphasized by the hypothesis that small farms prioritize sustainability and seek to reduce plastic waste in soil and food systems, especially if these alternatives match or exceed the benefits of plastic mulch. However, there is limited data available on the effectiveness of biodegradable paper (BP) and bio-based film (BB) in small-scale crop production, an area frequently affected by heat and drought stress. A field experiment was conducted on a strawberry field in Redlands, San Bernardino County, California during the seasons of 2022 and 2023, respectively. This study was conducted to identify the most appropriate alternative to plastic mulch in hill-side production systems under the Mediterranean climate as it relates to yield and fruit quality at harvest day. We used four common mulches in small farms in California, polyethylene mulch (PE), landscape paper mulch (PA), Coconut liner mulch (CL), Biodegradable plastic mulch (MB), and bare soil (control) with the most popular ever-bearing variety, ‘Albion’. To investigate the suitability and efficacy of his mulches, we recorded the soil properties (temperature, moisture, and pH) daily, fruit yield (fruit weight and fruits/plant) biweekly, and fruit quality (Soluble solid and color) at harvest considering farm stand or U-pick sale service. Our results indicate that the highest total yield in terms of total fruit weight and number of fruits per plant grows under MB, CL, and PF mulch respectively. No notable differences were observed among treatments in fruit quality parameters such as soluble solids and color. The soil under the coconut coir liner had the highest moisture content, compared to PE, BDM, and bare ground treatments. No significant difference was found among the treatments in weed control. By the end of the cropping period, all treatments adequately covered the soil surface. However, in the buried part of the mulches, the PA mulch exhibited considerable degradation before the end of the season, while the MB showed faster signs of biodegradation. Based on crop productivity and the different mulch efficacy observed in our study, this production system with CL and MB is a good alternative to compare to PE and PA mulches for ever-bearing hillside strawberry production in the Mediterranean climate.

Speakers

Amrita Mukherjee

University of California Agriculture and Natural Resources (UCANR)

Co-authors

Nolton Pattio

Jehovah Jireh Farm

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

Oral presentation (Individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

7:59am HST

Vegetable Crops Management 4 (VCM 4)

Thursday September 26, 2024 7:59am - 9:45am HST

Coral 2

Watermelon Rootstock Variety Trial to Understand the Impacts of Grafting on Watermelon Yield and Fruit Quality - Fayrouz Buojaylah
Effect of Biofungicides Containing Trichoderma and Grafting on Watermelon Productivity and Plant Health - Fayrouz Buojaylah
Canary Melons Cultigen Yield and Quality Evaluations in North Carolina, 2023 - Jonathan Schultheis
Watermelon Cultigen Yield Response to Fusarium oxysporum f. sp. niveum Incidence in North and South Carolina, USA - Stuart Michel
Effect of Biostimulants on Field Grown Watermelon (Citrullus lanatus) under Deficit Irrigation and Fertility. - Evan Christensen
Development of the winter artichoke production system in a subtropical climate - Shinsuke Agehara
Globe Artichokes - Variety Trials for Florida Production and Marketing Evaluations - Evelyn Fletcher

Moderator

Fayrouz Buojaylah

University ofr California, Cooperative Extension Stanislaus County

Thursday September 26, 2024 7:59am - 9:45am HST
Coral 2

Oral Sessions, Vegetable Crops Management 4

SUBJECT Vegetable Crops

8:00am HST

VCM 4 - Watermelon Rootstock Variety Trial to Understand the Impacts of Grafting on Watermelon Yield and Fruit Quality

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

Coral 2

In California, watermelon grafting has been gaining tremendous popularity over other graft-eligible vegetable commodities especially among large-acreage growers. To maintain viability and continued popularity of grafted watermelons in California, we conducted a watermelon rootstock variety trial in 2023 to evaluate the impact of different types of locally popular rootstocks on watermelon yield and quality. Seven watermelon rootstocks, grouped into three distinct types: Interspecific hybrid squash (Cucurbita maxima x Cucurbita moschata), Citron (Citrullus amarus), and Bottled gourd (Lagenaria siceraria), were grafted with a 45-ct field scion, ‘Warrior’ by a commercial greenhouse located in Mills River, NC. All grafted and non-grafted seedlings were then mechanically transplanted into a commercial field near Modesto, CA on 19 April 2023. The trial was arranged as a randomized complete block design with four replications for each treatment. Each plot was 24 m long and contained 13 triploid plants, either grafted or not, alongside four grafted or non-grafted pollenizers. Four harvests were conducted from 25 July to 17 Oct with the help of farm crew. Total yields at each harvest and fruit quality from the first harvest were recorded and compared among rootstock-scion combinations. For quality assessment, fruit length and width were measured with a yardstick. Sugar content (ºBrix) was measured by scooping the central flesh of each halved fruit using a portable reflectometer. Flesh firmness was evaluated using a fruit penetrometer, with measurements taken at spots located one-third and two-thirds of the distance from the blossom end after halving the melon. Rind thickness at the blossom and stem ends were measured using a digital caliper. The overall impact of grafting resulted in an average increase of total yield by 51.5% compared to the non-grafted control (54.7 vs. 36.1 tons per acre) with the most significant difference occurred at the second harvest (27.0 vs. 14.8 tons per acre). Differences of fruit quality between grafted and non-grafted watermelons were primarily observed for fruit firmness. The significant increase of firmness (4.9 vs. 3.4 kg.cm-2) for grafted fruit was also confirmed based on the results of taste sensory evaluation. Slight increases of fruit width and stem end rind thickness after grafting were also found. No changes of ºBrix after grafting were detected. Overall, grafting has proven to be a reliable method for enhancing watermelon yield and maintaining fruit quality in California. Continuous needs assessment will be performed to monitor any pressing issues of watermelon grafting in California.

Speakers

Fayrouz Buojaylah

University ofr California, Cooperative Extension Stanislaus County

Co-authors

Zheng Wang

Univ. of California Cooperative Extension

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

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

8:15am HST

VCM 4 - Effect of Biofungicides Containing Trichoderma and Grafting on Watermelon Productivity and Plant Health

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

Coral 2

The goal of the project is to evaluate the potential of reducing chemical fumigation in California's watermelon production using grafting and Trichoderma-based biofungicide. Two field experiments in 2022 and 2023 were implemented within commercial watermelon fields in Stockton and Modesto, CA. Each trial included three rootstocks (Cobalt, Flexifort, and RS841) grafted onto a 45-ct scion (Summer Breeze). Two Trichoderma-containing products were applied to the grafted and nongrafted seedlings through tray soaking at one day before transplanting or field chemigation at 30 and 62 days after transplanting (DAT). The application rates for soaking and chemigation were 45 g.75 L-1 of water and 2.2 kg.ha-1, respectively. All seedlings were mechanically transplanted during mid-May of both years into a split-split plot design with the Trichoderma product as the main factor and application method as the sub-plot. All treatments were replicated four times. Each treatment row was 18.6 m long and contained ten grafted or nongrafted triploids and three grafted or nongrafted pollenizers. Vine health was visually assessed three times for symptoms associated with soil-borne fungal pathogens. Canopy coverage was measured starting at 22 DAT in 2022 and 40 DAT in 2023 and thereafter at an approximate interval of two weeks for a total of six measurements. Harvest was conducted three times in 2022 and twice in 2023 to analyze yield and quality differences among treatments. Runner and root samples were taken amid the harvest and shipped to the UC Davis Fungal Pathology Lab for further identification. Results indicated that the Trichoderma-containing bio-fungicides were not as effective as grafting on preventing vine decline and maintaining canopy coverage in both trials. The synergistic effects of grafting and Trichoderma inoculation provided some but limited benefits to plant health compared to the single factor of grafting. The overall influence of biofungicides on yield was also less notable than that of grafting regardless of application method. For fruit quality, grafting dominated the impacts over biofungicides on fruit firmness and rind thickness in both trials. Charcoal rot (Macrophomina phaseolina) with other putative co-infestations of Fusarium pathogens were diagnosed from nongrafted inoculation-free plots in 2022 while no significant soil-borne diseases were identified from 2023. Overall, grafting with multi-pathogen resistant rootstocks prove to be a reliable method for enhancing watermelon yield while maintaining crop health. More work is still needed to further explore the optimal application protocols tailored to grower’s farming system to maximize the effects of biofungicide.

Speakers

Fayrouz Buojaylah

University ofr California, Cooperative Extension Stanislaus County

Co-authors

Zheng Wang

Univ. of California Cooperative Extension

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

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

8:30am HST

VCM 4 - Canary Melons Cultigen Yield and Quality Evaluations in North Carolina, 2023

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

Coral 2

Canary melons, Cucumis melo var. inodorus, are grown in the United States, with most acreage produced in California and Arizona. There is very limited production acreage in the southeastern United States, including North Carolina. No statistics are gathered by USDA on canary melons as this type of melon is truly a specialty melon. The goal of this study was to determine how well adapted canary melon cultigens are with respect to yields and quality when grown in North Carolina and to gauge the possibilities of producing this crop as a commercial option in the state. Fourteen cultigens were evaluated from eight different seed companies for yield and size over 16 harvests, flesh firmness and sweetness, and shape and rind characteristics. Statistical design was a randomized complete block with four replications and mean separation across measures was conducted using a LSD test at the P

Speakers

Jonathan Schultheis

North Carolina State University

Jonathan Schultheis is a Professor in the Department of Horticultural Science at North Carolina State University. He has worked exclusively with North Carolina State University for over 35 years. He research and extension work primarily involves cucurbit crops and sweetpotatoes. Key... Read More →

Co-authors

Andrew Pfefferkorn

North Carolina State University

Baker Stickley

North Carolina State University

Brandon Parker

North Carolina State University

Stuart Michel

NC State University

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

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

8:45am HST

VCM 4 - Watermelon Cultigen Yield Response to Fusarium oxysporum f. sp. niveum Incidence in North and South Carolina, USA

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

Coral 2

Fusarium wilt of watermelon, caused by the soilborne pathogen Fusarium oxysporum f. sp. niveum (FON), is a major disease impacting the watermelon industry. FON can severely reduce yields and is easily dispersed. Cultivar resistance is a desired control strategy due to high fungicide and grafting costs. In 2021 and 2022, triploid watermelon cultivars were evaluated at two locations (Clayton, NC and Charleston, SC) for their tolerance to FON. Eight common cultivars were evaluated for disease incidence and yield at both locations in both years. In 2022, two unreleased cultigens were also evaluated at both locations. All studies used a randomized complete block design with four replications. ‘Fascination’ grafted to ‘Carolina Strongback’ rootstock was included as a control each year. Disease incidence was measured every week starting three weeks after transplanting and until the first harvest at each location. Fruit weights and counts were taken to measure yield. In 2021, ‘Fascination’ had the lowest disease incidence at 75% in NC and ‘Embasy’ had the lowest incidence at 15% in SC. ‘Joy Ride’ had 100% incidence in NC and ‘Shoreline’ had the highest incidence in SC at 68%. Yields correlated with disease incidence with ‘Fascination’ having the highest yield of the ungrafted treatments in NC with 17,878 lb/ac (pounds per acre) and ‘Embasy’ with 22,687 lb/ac in SC. ‘Shoreline’ was the lowest yielding at both locations with 6,556 lb/ac in NC and 5,376 lb/ac in SC. The grafted ‘Fascination’ treatment had the lowest disease incidence and the highest yield at both locations in 2021. In 2022, the unreleased cultigen HMC633802 had the lowest disease incidence at both locations with 50% in NC and 51% in SC. Of the eight common cultivars, Fascination had the lowest incidence in NC at 83% and El Capitan had the lowest in SC at 52%. ‘Shoreline’ had the highest incidence at both locations with 100% in NC and 94% in SC. Yields correlated with disease incidence. Unreleased cultigen HMC633800 had the highest yield of the ungrafted treatments in NC with 15,575 lb/ac and Powerhouse had the highest yield in SC with 27,243 lb/ac. The grafted ‘Fascination’ treatment had the lowest incidence and highest yield at both locations in 2022. The cultigens we evaluated provided minimal tolerance to FON in both years.

Speakers

Stuart Michel

NC State University

Co-authors

Anthony Keinath

Clemson University

Jonathan Schultheis

North Carolina State University

Lina Quesada

North Carolina State University

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

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

9:00am HST

VCM 4 - Effect of Biostimulants on Field Grown Watermelon (Citrullus lanatus) under Deficit Irrigation and Fertility.

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

Coral 2

The impacts of climate change and drought threaten water supplies crucial for watermelon production. Rising fertilizer costs and off-site effects also pose problems for the sustainability of watermelon production. Biostimulants shown promise in helping plants maintain production under deficit irrigation conditions and may offset fertility addition through ecosystem services and stimulatory effects. In this study two watermelon cultivars (Crimson Sweet and Fascination) were treated with three biostimulant products (Mighty Mycorrhizae, Spectrum DS, and Continuum) and then subjected to reduced fertility (67% of recommended rate) and irrigation (75% evapotranspiration). Raised beds covered in plastic mulch were used with rows spaced 1.83 meters apart and plants 0.61 meters apart within rows. Growth metrics and stages were recorded and compared among treatments. Watermelon fruits were harvested at maturity over a one-week period and yield was compared. The final biomass was measured after harvest. Statistical analysis is ongoing, and a second year of this field trial will be completed in August 2024, allowing for final conclusions to be drawn.

Speakers

Evan Christensen

Utah State University

Co-authors

Dan Drost

Utah State University

Youping Sun

Utah State University

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

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

9:15am HST

VCM 4 - Development of the winter artichoke production system in a subtropical climate

Thursday September 26, 2024 9:15am - 9:30am HST

Coral 2

Artichoke (Cynara cardunculus var. scolymus) belongs to the sunflower family and is cultivated for its flower buds. Being adapted to Mediterranean climates, artichoke plants require adequate winter chilling for flower bud induction and yet is susceptible to freeze damage. Because of these climatic requirements, nearly 100% of artichoke production in the United States currently comes from California. Insufficient winter chilling is among the major environmental constraints for artichoke production in subtropical and tropical climates. We started this study in 2015 with the goal of developing artichoke as a new winter crop in Florida. First, we developed a protocol for artificial flower bud induction using a plant hormone, gibberellic acid (GA3). With the optimum rate and timing, GA3 application is highly effective in inducing bud formation, irrespective of winter chilling. Second, we evaluated eight cultivars based on earliness of bud formation, yield, and bud quality. ‘Imperial Star’ and ‘Green Queen’ were selected as the most promising cultivars in Florida, with the maximum yields of 17.3 and 11.8 t ha–1, respectively. The current artichoke production guide provides recommendations on GA3 application, cultivars, planting configurations, plastic mulch, and basic pest management. In 2023, artichoke was grown on about 12 hectares in Florida using the production guide we developed. We are currently testing additional hybrid cultivars and assessing nutritional values and postharvest quality to enhance the viability of artichoke as Florida’s new winter crop.

Speakers

Shinsuke Agehara

University of Florida

Co-authors

Weining Wang

University of Florida

Thursday September 26, 2024 9:15am - 9:30am HST
Coral 2

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

9:30am HST

VCM 4 - Globe Artichokes - Variety Trials for Florida Production and Marketing Evaluations

Thursday September 26, 2024 9:30am - 9:45am HST

Coral 2

The globe artichoke (Cynara cardunculus) is a large thistle crop of the Asteraceae family, native to the Mediterranean. Globe artichokes are a large, leafy plant, with edible component as an immature flower bud. With production dominated by California, Florida can provide a new commodity for southeastern growers while reducing our carbon footprint. Globe artichokes have not been a traditional crop in the state of Florida, even as a garden variety. This study demonstrates the need to focus on varieties for the subtropics. We evaluated the best performing artichoke variety in addition to the retail favorite by curb appeal. Within a farmer's market survey, more than 80% of shoppers voted for 'Green Queen' amongst five other varieties (Imperial Star, Green Globe Improved, etc.). It also represented the highest yielding, at 12,707 lbs/acre, followed by 'Imperial Star' at 11,484 lbs/acre. An artichoke was valued at $4 each globe, while the flower was $5 per stem during the Mother's Day market. The demand continues from chefs and newly transplanted retail shoppers.

Speakers

Evelyn Fletcher

University of Florida

I am the commercial row-crop Extension Agent for St. Johns County, FL.

Co-authors

Kelly Morgan

UF/IFAS CALS

Shinsuke Agehara

University of Florida CALS

Thursday September 26, 2024 9:30am - 9:45am HST
Coral 2

Oral presentation (Individual talk), Vegetable Crops Management 4

SUBJECT Vegetable Crops

11:29am HST

Vegetable Crops Management 3 (VCM 3)

Thursday September 26, 2024 11:29am - 1:40pm HST

South Pacific 4

Evaluating Faba Bean (Vicia faba) Performance Using Desalinated Irrigation Water and Compost Amendments in the Southwest - Jannatul Afroze
Investigating Microclimate Conditions and Vegetable Yield under Agrivoltaics Systems in Grafton, MA”. - Mamata Bashyal
Planning for Success: A Roadmap to Establishing a Certified Naturally Grown Production Plot - Shelby Mendoza
Fertility Management in Soilless Growth Media for Beet Crop Production. - Bryce Waugh
Adaptation of AgRobotics for Onion Production in High Organic Matter Soils - Mary Ruth McDonald
Effect of Mineral Nitrogen and Foliar Spraying of Humic Acid on Fresh and Dry Leaves and Roots Weights, and Root Length - Ali Omar
Dual-cropping Sweetpotato for Greens and Root Production - Laura Schulz
Effect Of Selenium Fertilization on Beta-carotene Accumulation in Hydroponically Grown Two cress Varieties - Adekunle Adeyeye
Effect Of Levels Of Magnesium Fertilization On The Carotenoid Accumulation Among Three Kale Cultivars Grown Hydroponically. - Alex Kofi
Red And Blue LED Lighting Effects On Hydroponically Grown 'Koba' Green Onion - Kent D. Kobayashi
Plant Health Aerial Mapping Integration In Precision Agriculture Systems - Wael Elwakil
Evaluation of Vegetable Soybean Adaptations to South Florida’s Tropical Climate - Xiaoying Li
Lettuce Cultivar Trials in a Deep-Water Culture (DWC) Hydroponic System - Alireza Rahemi

Moderator

Laura Schulz

Washington State University

Thursday September 26, 2024 11:29am - 1:40pm HST
South Pacific 4

Poster Session, Vegetable Crops Management 3

SUBJECT Vegetable Crops

11:30am HST

VCM 3 - Evaluating Faba Bean (Vicia faba) Performance Using Desalinated Irrigation Water and Compost Amendments in the Southwest

Thursday September 26, 2024 11:30am - 11:40am HST

South Pacific 4

Water and soil salinity pose a significant challenge to global food production, particularly in semi-arid and arid regions. In many of these areas, the only available irrigation water often has high salinity levels. Utilizing irrigation water with high salinity can lead to salt accumulation in the rhizosphere, causing reduced infiltration rates, yield losses, decreased crop quality, and even potential plant mortality. Two strategies to address water and soil salinity include integrating compost soil amendments and implementing water desalination techniques. In addition to these two strategies, legumes are suitable crops for enhancing bioproductivity and reclaiming marginal lands due to their symbiotic association with rhizobia bacteria that can increase soil nitrogen. The objective of this study was to evaluate how the combined use of saline and desalinated water for irrigation, along with compost amendments, impacts faba bean germination, growth, physiology, and nodulation. Two common faba bean cultivars, Broad Windsor and Aquadulce were planted in fall of 2023 in field plots at the arid Brackish Groundwater National Desalination Facility, Alamogordo, NM, USA. Faba bean cultivars were grown in a combination of treatments of mulched composted wood with soil, bare soil, saline (1.97 dS/m) irrigation water, and desalinated (0.80 dS/m) irrigation water. Germination rates, plant nutrient composition, chlorophyll index, nodulation weight and number, along with root weight were measured. Preliminary results show that compost treatment as a main effect had a significant effect on faba bean germination rates with a 22-26% reduction in germination at 18, 25, and 35 days after planting (DAP) in plots with compost. By 107 days after planting, faba bean plants in the compost-treated plots showed no signs of nodulation, whereas the majority of plots without compost had nodules present. Water treatment significantly influenced the chlorophyll index of faba beans at 107 DAP; plants irrigated with saline water exhibited higher chlorophyll indexes. Compost treatments could have influenced germination rates due to variations in soil temperature, while nodulation might have been affected by adequate nitrogen potentially supplied by the compost. Upon completion of the current season and subsequent second season, we will have a more comprehensive basis to evaluate the relationships between compost application, saline irrigation water treatments, and their impacts on faba bean growth.

Speakers

Jannatul Afroze

New Mexico State University

Co-authors

Breana Smithers

University of North Texas

Israel Joukhadar

New Mexico State University

Miguel Acevedo

University of North Texas

Stephanie Walker

New Mexico state University

Thursday September 26, 2024 11:30am - 11:40am HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

11:40am HST

VCM 3 - Investigating Microclimate Conditions and Vegetable Yield under Agrivoltaics Systems in Grafton, MA”.

Thursday September 26, 2024 11:40am - 11:50am HST

South Pacific 4

Agrivoltaics is the simultaneous production of both solar energy and crops on the same land. The success of crops grown underneath the panels depends on the crop type, soil composition, regional climate conditions, and panel configuration (height, row spacing, tilt angle, and tracking system). There is a need for more research-based guidance on the trade-offs between energy and crop production in agrivoltaics systems. The objective of this study was to compare the microclimate conditions and crop performance within a solar array to the control (without a solar array). The on-farm agrivoltaics study was conducted from July to September 2023 in Grafton, MA, using two contrasting crops: butternut squash (sun-loving) and Boston lettuce (shade tolerant). Microclimate variables such as photosynthetically active radiation (PAR), air temperatures, soil temperatures, soil moisture, and relative humidity were monitored at different transect positions within the solar array [BP 1 (under leading panels), BP 2 and BP 3 (between two panels), and BP 4 (under the back panel)] and control. Data were analyzed in R statistical software using an independent sample t-test to compare control to array and test and one-way ANOVA to compare each bed position within the array only. Preliminary findings showed higher mean and maximum PAR in control than in BP 1, BP 2, and BP 4 within the array. Air temperature (mean and maximum) was found to be higher in control than in the array. Mean and maximum soil temperature was highest in control when compared to BP 1 and BP 2 under the array. Similarly, mean relative humidity was found to be significantly higher in the control than in the array. The chlorophyll index of butternut squash showed a positive correlation with decreasing PAR, suggesting potential adaptive responses to varying light conditions. Butternut squash fruit yield was similar across the four different bed positions under the array, and lettuce yield under the array was similar to that of the control area. Further continuation of this study in 2024 provides insights for growers about the successful production of butternut squash and lettuce production under the agrivoltaics system.

Speakers

Mamata Bashyal

University of Massachussets

Co-authors

Clem Clay

University of Massachusetts

Sam-Glaze Corcoran

University of Massachusetts, Amherst

Thursday September 26, 2024 11:40am - 11:50am HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

11:50am HST

VCM 3 - Planning for Success: A Roadmap to Establishing a Certified Naturally Grown Production Plot

Thursday September 26, 2024 11:50am - 12:05pm HST

South Pacific 4

In the face of escalating environmental concerns, the horticultural sector is encouraged to pivot towards more sustainable and environmentally friendly production practices. Specifically, Certified Naturally Grown (CNG) emerged in 2002 as a new production system for small-scale producers rooted in organic farming principles and relying on peer-reviewed certification that fosters a community network. However, there is limited literature on the process of achieving CNG certification. Hence, this research strives to provide a detailed roadmap of the different phases of setting up a demonstrational CNG production system at the Oklahoma State University Student Farm including strategic planning and execution phases. The research plot is intended to serve as both an educational tool and a practical guide for growers aiming to transition to CNG practices. The implementation of this project began with familiarizing ourselves with the CNG organization, their inspection processes and planning accordingly. This is crucial to ensure the plot meets CNG criteria, focusing on sustainable practices and ecological balance from the outset. Next, the planning phase encompassed establishing the research plot including site selection, soil analysis, anticipated barriers of CNG certification, plot design and layout, resource assessment, and an implementation timeline. The planning phase aids in physically establishing the CNG demonstration plot and ensuring its role as a research and educational hub. By accurately addressing each planning component, the project aims to lay a solid foundation to demonstrate the viability of CNG practices in Oklahoma, stimulate community engagement, and promote a deeper understanding of sustainable agriculture practices. Ultimately, this project seeks to illustrate the detailed strategic planning and preparation required to develop a CNG production system. The education tools we develop will provide a template for producers aiming for CNG certification. With this initiative, we aim to educate growers on sustainable and resilient production methods and enable a transition towards them.

Speakers

Shelby Mendoza

Oklahoma State University

Thursday September 26, 2024 11:50am - 12:05pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:00pm HST

VCM 3 - Fertility Management in Soilless Growth Media for Beet Crop Production.

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

South Pacific 4

Greenhouse production is experiencing a rise, with more emphasis being placed on sustainability and efficient resource utilization. Accurate fertilizer applications are now more crucial than ever across various production systems. Soilless growth media possess different physical and chemical properties compared to soil, resulting in differences in nutrient retention capabilities. Because of this, it is imperative to apply precise fertilizer rates. This study evaluated 14 fertilizer blends with varying nitrogen (0-120ppm), phosphorus (0-120ppm), and potassium rates (0-120ppm). ‘Red Ace’ beet seeds were planted into 1-pint pots with Berger BM6 and plants were hand watered weekly with each treatment fertilizer rate to a 10% leaching fraction. Dry shoot weight, fresh root weight, dry root weight, number of leaves, and SPAD were taken as end measurements. This study found that high rate of nitrogen increased fresh shoot weight, while higher rates of potassium increased root weight. More studies should be done to dial in fertilizer rates for different specialty crops grown soilless greenhouse media.

Speakers

Bryce Waugh

Grad Student, Oklahoma State University

Co-authors

Bruce Dunn

Oklahoma State University

Thursday September 26, 2024 12:00pm - 12:10pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:10pm HST

VCM 3 - Adaptation of AgRobotics for Onion Production in High Organic Matter Soils

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

South Pacific 4

The high organic matter soil (50 -80%) in the Holland Marsh, Ontario, Canada, is ideal for growing root and bulb vegetables but weeds also thrive. There are few registered herbicides and increasing herbicide resistance necessitates hand-weeding, but labor shortages and increased costs increase the interest in alternative methods. The solar-powered FarmDroid FD20 is one option, if adapted to work in vegetables. The FarmDroid was used to seed and weed onions on 2.8 ha of a commercial farm with weed control issues. The robot seeded 21 beds ~800 m long, with 4 single rows in each bed, and seeds 3.4 cm apart within the row, at 225 meters per hour. Seeding took 81 hours. Weeding was done with using a cultivator with metal tines to remove weeds growing between the rows it had seeded, at a speed of 500 m/hr. Weed counts were consistently higher in the robot-weeded than conventional-farmed sections (408 and 186 weeds/m, respectively), largely because of the inability of the robot to weed within the rows. There were no differences in yield. Small scale trials were conducted to compare conventional seeding of four double rows, with single rows as above and clusters of 3 seeds, 12 cm apart in the row. Emergence was 25, 35 and 17 plants/m for single, double and triple cluster seeding, respectively. There were no differences in yield at harvest (73-76 t/ha) but there were significantly more jumbo onions (42%) in those seeded in clusters, compared to the others (9 and 1%). A separate trial assessed seeding accuracy with increased speed. Emergence was highest for onions seeded at 200 m/hr with a significant decrease at speeds of 300 – 500 m/hr. Seeding in clusters shows promise for faster seeding and larger onions. Modifications to improve the configuration of tines for weeding are ongoing.

Speakers

Mary Ruth McDonald

University of Guelph

Co-authors

Chuck Baerisch

Haggerty AgRobotics

Geoffry Farintosh

University of Guelph

Ifesinachi Ezeh

University of Guelph

Kevin Vander Kooi

Univ. of Guelph

Kristen Obeid

Ontario Ministry of Agriculture, Food and Rural Affairs

Thursday September 26, 2024 12:10pm - 12:20pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:20pm HST

VCM 3 - Effect of Mineral Nitrogen and Foliar Spraying of Humic Acid on Fresh and Dry Leaves and Roots Weights, and Root Length

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

South Pacific 4

Lactuca sativa L., commonly known as lettuce, represents a vital winter leafy vegetable crop cultivated globally, including Libya, owing to its rich nutritional content and rapid growth characteristics. Enhancing the vegetative growth of lettuce and similar leafy crops often involves employing various horticultural practices, with fertilization being a key component utilizing diverse nutrient sources. Two field experiments conducted at the Department of Horticulture Farm, Omar Al-Mukhtar University, situated in Al-Jabal Al-Akhdar region of Libya in 2021 and 2022 aimed to evaluate the effects of ground-applied urea fertilizer (46% nitrogen) at rates of 0, 60, 120, and 180 kg.ha⁻¹, combined with foliar applications of different concentrations of humic acid (0, 1, 1.5, and 3 ml.L⁻¹), on the fresh and dry weights of leaves and roots, as well as root length of lettuce cv. Nickerson-Zwaan plants under local environmental conditions. Each experiment comprised 16 treatments representing all possible combinations of the two factors and followed a randomized complete block split-plot design with four replications per treatment. Results revealed that increasing levels of mineral nitrogen and humic acid resulted in a significant increase of fresh and dry weights of lettuce leaves and roots across both growing seasons as compared to the control treatment, with consistent effects observed for the interaction between nitrogen fertilization sources and their respective rates. While no significant impact was observed on root length due to urea fertilizer or humic acid spray in either growing season, application of 180 kg.ha⁻¹ urea fertilizer in the second season showed a tendency towards greater root length compared to other treatments. Thus, the findings suggest that the application of mineral nitrogen fertilizer and humic acid spray holds promise for enhancing the vegetative growth of lettuce plants in Al-Jabal Al-Akhdar region of Libya.

Speakers

Ali Omar

Omar Al-Mukhtar University

Thursday September 26, 2024 12:20pm - 12:30pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:30pm HST

VCM 3 - Dual-cropping Sweetpotato for Greens and Root Production

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

South Pacific 4

Sweetpotato (Ipomoea batatas) is a nutritious crop that produces edible roots, stems, and leaves. The tender vine tips, including both leaves and stems, are consumed as a vegetable in many regions of the world, including the Pacific Islands, Asia, and parts of Africa. A field experiment in Mount Vernon, WA evaluated time of vine tip (15 cm from the end of every vine) harvest on sweetpotato root yield of breeding lines USDA-04-284 (semi-erect growth habit), USDA-04-136 and USDA-04-791 (both with spreading growth habit). Treatments included no harvest during the season (control treatment, 1 harvest at time of root harvest), early harvest (8–12 weeks after transplanting, 4 harvests), late harvest (12–14 weeks after transplanting, 3 harvests), and continuous harvest (8–14 weeks after transplanting, 5 harvests). Vine tips were harvested at 2-week intervals during the harvest period, with an additional harvest for all treatments (including control) immediately before root harvest. Breeding line USDA-04-284 (semi-erect growth habit) produced 330 g of greens (fresh weight) per plant on average for all harvest treatments, which was significantly higher (p

Speakers

Laura Schulz

Washington State University

Co-authors

Carol Miles

Washington State University

Jacob Blauer

Washington State University

Laurel Moulton

Washington State University

Phil Wadl

United States Department of Agriculture, Agricultural Research Service

Thursday September 26, 2024 12:30pm - 12:40pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:40pm HST

VCM 3 - Effect Of Selenium Fertilization on Beta-carotene Accumulation in Hydroponically Grown Two cress Varieties

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

South Pacific 4

EFFECT OF SELENIUM FERTILIZATION ON BETA-CAROTENE ACCUMULATION IN HYDROPONICALLY GROWN TWO CRESS VARIETIES. A.O. Adeyeye*; T. Nzaramyimana, Ph.D.; A. Kofi. College of Agriculture, Community, and the Sciences, Kentucky State University, Frankfort, KY 40601. Advanced plant cultivation techniques such as hydroponic vegetable planting, coupled with targeted soil micronutrient fertilization, exemplify sustainable agriculture's innovative approach to maximizing crop yields, enhancing nutritional quality, and minimizing environmental impact. This study will investigate the effect of selenium fertilization on the accumulation of beta-carotene in two varieties of hydroponically grown watercress. Hydroponic cultivation offers a controlled environment for plant growth, allowing precise manipulation of nutrient levels to optimize desired outcomes. Selenium, an essential micronutrient for both plants and animals, has been shown to influence the synthesis of secondary metabolites in plants, including carotenoids such as beta-carotene, which are important antioxidants and precursors of vitamin A. In this innovative idea, the experiment will be conducted using two cress varieties, (watercress) and (Upland cress), subjected to different levels of selenium fertilization. Selenium treatments will be applied according to a randomized experimental design, with each variety divided into multiple treatment groups receiving varying concentrations of selenium fertilizer. The hydroponic system provided consistent environmental conditions, including nutrient solution composition, pH, temperature, and light intensity, throughout the experiment. The beta-carotene content in watercress leaves will be quantified using High-performance Liquid chromatography (HPLC)analysis which is a technique used in analytical chemistry to separate, identify, and quantify components in mixtures and this allows for accurate measurement of carotenoid levels. Statistical analysis of the data will reveal significant differences in beta-carotene accumulation between selenium-treated and control groups within each watercress variety. Moreover, variations in beta-carotene accumulation will be observed between the two watercress varieties in response to selenium fertilization, indicating potential genotype-specific responses. Overall, the results will demonstrate that selenium fertilization influences beta-carotene accumulation in hydroponically grown watercress, with implications for agricultural practices and human nutrition. Understanding the interactions between selenium supplementation and carotenoid synthesis in watercress can inform strategies to enhance the nutritional quality of crops and promote sustainable agricultural production systems. Keywords; Selenium fertilization, Beta-carotene, Hydroponic, Watercress varieties, Agricultural sustainability, Crop yields, Environmental impact, Spectrophotometric analysis,

Speakers

Adekunle Adeyeye

Kentucky State University, Frankfort, KY

Co-authors

Alex Kofi

Kentucky State University

Graduate Research Assistant

THEONESTE NZARAMYIMANA

Kentucky State University

Thursday September 26, 2024 12:40pm - 12:50pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

12:50pm HST

VCM 3 - Effect Of Levels Of Magnesium Fertilization On The Carotenoid Accumulation Among Three Kale Cultivars Grown Hydroponically.

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

South Pacific 4

Phytonutrients in fruits and vegetables are crucial in promoting human health and preventing various diseases. Among these are carotenoids that are found abundantly in green leafy vegetables like kale, which have garnered significant attention due to their numerous health benefits, including antioxidant and anti-inflammatory properties. Despite kale’s reputation as a nutritional powerhouse, little research has focused on the effect of magnesium fertilization on carotenoid production and accumulation in this vegetable. This study aims to address this gap by investigating the impact of different rates of magnesium fertilization on the carotenoid contents and elemental nutrient levels of three hydroponically grown kale cultivars. The Darkibor, Mamba, and Red Russian kales would be grown hydroponically using Hoagland solution in a greenhouse. Different magnesium rates at 0 mgL-1, 12.3 mgL-1, 24.6 mgL-1 and 59.2 mgL-1 would be used. Carotenoid contents and levels in the three kale varieties will be analyzed using High-performance Liquid Chromatography. Additionally, an Agilent 7500ce inductively coupled plasma-mass spectroscopy (ICP-MS) system will be used to measure their elementary nutrient levels. Data would be analyzed using the PROC GLM analysis of variance (ANOVA) and regression analysis procedure of the SAS v9.1 software package. At the end of the experiment, it is expected that increased rates of magnesium fertilization will lead to a significant increase in the accumulation of carotenoid and elemental nutrient levels in each kale cultivar. Understanding how magnesium fertilization influences carotenoid accumulation and other nutrient levels in kale could improve nutritional quality, thereby reducing reliance on dietary supplements to address nutrient deficiencies. Keywords: Phytonutrients, Magnesium, Carotenoids, Kale, Antioxidants

Speakers

Alex Kofi

Graduate Research Assistance, Kentucky State University

Graduate Research AssistantResearch interest: Controlled Environment Agriculture especially in hydroponics

Co-authors

Adekunle Adeyeye

Kentucky State University, Frankfort, KY

THEONESTE NZARAMYIMANA

Kentucky State University

Thursday September 26, 2024 12:50pm - 1:00pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:00pm HST

VCM 3 - Red And Blue LED Lighting Effects On Hydroponically Grown 'Koba' Green Onion

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

South Pacific 4

Food safety, environmental impact, and efficient energy usage are growing concerns in horticultural production systems. In Hawaii, 'Koba' and local strains of green onion can be planted year round. The use of artificial lighting in green onion production could be a solution to help address the above concerns. The objective of this study was to compare the effects of red and blue LED lighting on the growth of 'Koba' green onion plants in a noncirculating hydroponic system. 'Koba' green onion (Allium fistulosum) seeds were germinated in Oasis® cubes under T5 high output fluorescent lighting in the lab. Seedlings were then transferred to 5.1-cm net pots, which were placed in 1.9-liter containers containing a hydroponic nutrient solution of Hydro-Gardens' Chem-Gro lettuce formula 8-15-36 hydroponic fertilizer with added calcium nitrate (19% Ca and 15.5% N) and magnesium sulfate (9.8% Mg and 12.9% SO4). Half of the seedlings were grown under red LED lighting (82 µmol/m2/s, 12-h photoperiod) and half under blue LED lighting (82 µmol/m2/s, 12-h photoperiod). Data was collected at the end of the experiment. At the end of the study, there were significant differences in plant height, number of leaves per plant, stem diameter, total leaf length per plant, leaf dry weight per plant, and root dry weight per plant. For all these variables, red LED lighting resulted in greater values than those for blue LED lighting. In conclusion, different LED lighting could be used to supply artificial lighting for 'Koba' green onion plants. Red LED lighting enhanced the growth of 'Koba' green onions.

Speakers

Kent D. Kobayashi

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

Co-authors

Brylin Nelson

Univ of Hawaii at Manoa

Thursday September 26, 2024 1:00pm - 1:10pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:10pm HST

VCM 3- Plant Health Aerial Mapping Integration In Precision Agriculture Systems

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

South Pacific 4

Aerial multispectral imaging is a great tool for early detection of plant health stresses. There is a variety of sensing hardware with even more options for data analysis ranging in their ease of use and computing power requirements. These tools have been used very successfully in research settings such as breeding trials, nutrient management evaluations, and pesticide efficacy trials. These technologies have tremendous potential benefits if utilized in commercial production systems. While some agronomic crop producers have been using some of these technologies to some extent, there have been various barriers to adoption in specialty crop production. Data collection, analysis, and computing power limitations are some of the primary challenges. However, we find that there is a serious limitation in integration and data output compatibilities from the analysis side to plugging in precision ag equipment. In this project, we examine multiple systems and platforms from data collections to creating decision maps used in field equipment. This project is conducted in partnership with specialty crop growers and aerial service providers. We are in the process of streamlining the process of data collection, analysis, and creation of decision maps, to optimize the use of ground based or aerial fertility and pesticide precision applicators.

Speakers

Wael Elwakil

University of Florida

Thursday September 26, 2024 1:10pm - 1:20pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:20pm HST

VCM 3 - Evaluation of Vegetable Soybean Adaptations to South Florida’s Tropical Climate

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

South Pacific 4

Speakers

Xiaoying Li

University of Florida, IFAS

Thursday September 26, 2024 1:20pm - 1:30pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:30pm HST

VCM 3- Lettuce Cultivar Trials in a Deep Water Culture (DWC) Hydroponic System

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

South Pacific 4

Lettuce (Lactuca sativa L.) is a leafy vegetable in the Asteraceae family and is classified into various types, such as Romaine, Butterhead, Crisphead (Iceberg and Batavian), Latin, Leaf, and Stem. Lettuce propagates by the seeds. The seedling can grow in soil or a hydroponic system in a controlled environment Agriculture (CEA) system. This study was conducted to study the ability of different types of lettuces to grow in a hydroponic system and to assess the effect of light, humidity, and temperature on the yield. The experiment was conducted twice (2023 and 2024) in the Department of Agricultural Science lab at Morehead State University. Four lettuce cultivars, including 'Gustav's Salad' and 'May Queen' as the Butterhead type, 'Ice Queen' as a Crisphead type, and 'Lollo' as the Leaf type, were planted directly on rock wools (Rockwool Starter Plugs) in 2-inch Garden Net Pot in hydroponic containers. The commercial aquarium pumps constantly aerated the nutrient solution. Plants were fertilized with liquid plant food, and the Standard Hydroponic solution controlled the pH. The artificial light was provided by a mix of different lights (µmol/m2/s), including LEC, LED, and Fluorescent, for 16 hours daily under different temperatures (°C) and humidity (%). Biological control products were used for pest and disease control. Harvesting was done after 60 days, and fresh and dried yields of leaves were calculated. The roots were also collected and weighed. Dried leaves and roots were ground and analyzed. The primary results show significant differences among different cultivars.

Speakers

Alireza Rahemi

Morehead State University

Co-authors

Alyssa F. Covell

Amy S. Collick

Caleen L. Treadway

Hudson M. Cox

Larry N. Goble

Mary H. Jackson

Mollie K. Mayabb

Randy W. Wilburn

River E. Crepps

Rylie B. St. Clair

Thursday September 26, 2024 1:30pm - 1:40pm HST
South Pacific 4

Poster presentation (individual talk), Vegetable Crops Management 3

SUBJECT Vegetable Crops

1:59pm HST

Vegetable Crops Management 5 (VCM 5)

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

South Pacific 1

Evaluation of Wireworm Resistant Sweetpotato Cultivars in Western Washington - Laura Schulz
Variation in Toxic Element Presence in Sweetpotato Storage Roots From A Small Plot Trial: Sampling Implications - Arthur Villordon
Striving to stay clean: Production of sweetpotato nuclear stock used for certified seed growers in North Carolina - Christie Almeyda
Effects on yield, quality, sugar content and soil health indicators of foliar and soil applied Chlorella vulgaris in ‘Beauregard’ sweetpotato (Ipomoea batatas [L.] Lam). - Brian Ward
The Effect of Potassium Fertilization on Potato Tuber Nutrition in the Columbia Basin of Oregon - ruijun qin
Predicting Potato Tuber Yield Through Hyperspectral Signals and Machine Learning - Ravinder Singh
Evaluating King Stropharia Mushroom as an Intercrop in Asparagus and Tomato Production - Olalekan Sipasi

Moderator

Laura Schulz

Washington State University

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

Oral Sessions, Vegetable Crops Management 5

SUBJECT Vegetable Crops

2:00pm HST

VCM 5 - Evaluation of Wireworm Resistant Sweetpotato Cultivars in Western Washington

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

South Pacific 1

Sweetpotato (Ipomoea batatas) is a nutritious, productive, and resilient crop that is grown worldwide and is gaining popularity throughout the U.S. In western Washington, wireworms (Agriotes lineatus, A. obscurus, and Limonius canus) are the primary pest impacting sweetpotato production. Wireworm resistant cultivars can provide an effective and sustainable pest management tool for growers. A field experiment in Mount Vernon, WA included nine sweetpotato cultivars and breeding lines: wireworm-susceptible cultivars Bayou Belle, Beauregard, Covington, and Orleans; wireworm-resistant cultivars Cascade and Monaco; and wireworm-resistant breeding lines USDA-04-136, USDA-04-284, and USDA-04-791. Storage roots were graded according to USDA sweetpotato categories and root weight, number, and wireworm damage [Wireworm-Diabrotica-Systena (WDS) severity index] were measured. Marketable yield ranged from 22 t/ha (USDA-04-136) to 57 t/ha (‘Bayou Belle’) (p

Speakers

Laura Schulz

Washington State University

Co-authors

Carol Miles

Washington State University

Jacob Blauer

Washington State University

Laurel Moulton

Washington State University

Louis Nottingham

Washington State University

Phil Wadl

United States Department of Agriculture, Agricultural Research Service

Srijana Shrestha

Washington State University

Thursday September 26, 2024 2:00pm - 2:15pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

2:15pm HST

VCM 5 - Variation in Toxic Element Presence in Sweetpotato Storage Roots From A Small Plot Trial: Sampling Implications

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

South Pacific 1

The overarching goal of FDA’s Closer to Zero (C2Z) action plan is to reduce dietary exposure to contaminants, in foods commonly eaten by babies and young children, to as low as possible while maintaining access to nutritious foods. In addition to establishing action levels for specific toxic elements (TEs), C2Z proposes to develop new and improved testing methods to measure lower levels of contaminants in food and monitor levels over time to determine potential adjustments to proposed action levels. These proposed testing and monitoring activities represent potential added costs to the producer. The sweetpotato (Ipomoea batatas L.) is a leading baby food raw product but very little information is available on the appropriate frameworks for optimal sampling procedures to ensure accuracy and precision of surveys, especially at the field scale. A field trial to investigate the role of commonly used soil amendments in reducing storage root accumulation of arsenic (As), cadmium (Cd), and lead (Pb) revealed interesting trends that merits further investigation. Three random U.S. No.1-sized storage roots were sampled from each of three random plants from each of two unamended (control) plots (plot size=12’ x 3.3’) and analyzed for TE presence at a commercial laboratory. The Pb and Cd content of storage roots from cultivars ‘Bayou Belle’ (BB) (SDs: Cd=1.1, Pb=1.3) and ‘Beauregard’ (BX) (SDs; Cd=1.8 Pb=1.3, Cd=) showed more variability relative to As (SDs: BB=0.5, BX=0.6). There were no differences between two cultivars for all TEs measured. A possible follow-up study could investigate plant- or soil-based variables that contribute to variation in Pb and Cd accumulation. Such findings can be used to improve the accuracy and precision of sampling approaches to enable producers to meet C2Z goals, especially as it concerns sampling of storage roots for monitoring and enforcement purposes.

Speakers

Arthur Villordon

Professor, Louisiana State University AgCenter

Thursday September 26, 2024 2:15pm - 2:30pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

2:30pm HST

VCM 5 - Striving to stay clean: Production of sweetpotato nuclear stock used for certified seed growers in North Carolina

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

South Pacific 1

The Micropropagation and Repository Unit (MPRU) produces, maintains and distributes meristemmed-tip culture, virus-tested, indexed, true-to-type sweetpotato nuclear plants to certified seed growers in NC. Under the certification program, seed growers use nuclear plants for production of G0 plants in greenhouses, and subsequently G1 and G2 plants and storage roots (seed) in the field. All these materials are inspected and certified by NC Crop Improvement Association, Inc. (NCCIA). The MPRU is a clean center for sweetpotato under the National Clean Plant Network (NCPN) umbrella. It works closely with the NC State sweetpotato breeding and genetics program to clean advanced selections yearly. The MPRU distributes about 90,000 nuclear plants to NC certified seed growers every year. It is estimated that about 70% of the commercial sweetpotato acreage in NC is planted annually with stocks derived from the MPRU. It is known that the accumulation and perpetuation of viruses in sweetpotato is a major constraint for production of seed and the commercial crop. The aphid-transmitted potyvirus complex is prevalent in NC and comprises Sweet potato feathery mottle virus (SPFMV), Sweet potato virus G (SPVG), Sweet potato virus C (SPVC) and Sweet potato virus 2 (SPV2). In order to evaluate the performance and quality of clean seed after it had been integrated into commercial sweetpotato operations, NCPN field trials were carried out in 2021 and 2023 with Covington and Beauregard as evaluated varieties. Because sweetpotato is vegetatively propagated, viruses and mutations can accumulate readily which can lead to cultivar decline. G1 seed was used as a reference to compare the yield and virus incidence of growers’ generation 2 (G2), generation 3 (G3) and generation 4 (G4) seed roots (grown in the growers’ seed production fields 1, 2 or 3 years following the year of clean seed production). Virus detection data suggested a low incidence of viruses (mainly SPFMV) on G1 material. Potyviruses (mainly SPVG, SPVC and SPFMV) started to be prevalent on G2 and G3 material. In the older generation evaluated (G4), all potyviruses (SPVG, SPVC, SPFMV and SPV2) were detected. In general, the prevalence of four potyviruses was associated to higher seed generations, indicating a buildup over the years on clean seed regardless of the variety. Yield data suggested a negative impact due to virus infections in Beauregard. This study will allow us to understand the impact of clean seed on the economic value of the crop to educate growers and stakeholders.

Speakers

Christie Almeyda

MPRU Director, North Carolina State University

Co-authors

Craig Yencho

North Carolina State University

Dustin Auman

North Carolina Crop Improvement Association, Inc

Kenneth Pecota

North Carolina State University

Thursday September 26, 2024 2:30pm - 2:45pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

2:45pm HST

VCM 5 - Effects on yield, quality, sugar content and soil health indicators of foliar and soil applied Chlorella vulgaris in ‘Beauregard’ sweetpotato (Ipomoea batatas [L.] Lam).

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

South Pacific 1

Commercial sweet potato production has seen a recent surge in both fresh market and processing acreage in South Carolina. Producing quality conventionally and organically grown sweetpotatoes is a challenge in South Carolina due to numerous biotic and abiotic factors. One of the most important deciding factors on sweetpotato yield is germplasm and fertility. In this study we examined effects on yield and quality of foliar and soil applied Chlorella vulgaris (CV) in ‘Beauregard’ sweetpotato (Ipomoea batatas [L.] Lam). Chlorella vulgaris (EnSoil Algae, Enlightened Soil Corp) is marketed under the USDA/APHIS category of soil amendments and Plant Growth Enhancers (PGE). This study was conducted in 2022-2023 in a randomized complete block full factorial design with 4 replications and a total of 17 treatments with a product rate of 250ml/Ac, including the following: 1) Unfertilized Control, 2) 100 % Preplant Granular Fert. (PGF), 3) Soil Algae Application (SAA), 4) Foliar Algae Application (FAA), 5) 100% PGF SAA, 5) 100% PGF SAA, 6) 100% PGF FAA, 7) 100% PGF SAA FAA, 8) SAA FAA, 9) 25% PGF SAA 75% Drip Irrigation Fert.(DIF), 10) 25% PGF FAA 75% DIF, 11) 25% PGF SAA FAA 75% DIF, 12) 25% PGF SAA, 13) 25% PGF FAA, 14) 25% PGF SAA FAA, 15) 25% PGF 75% DIF, 16) 75% DIF, 17) 25% PGF. Results were mixed over time with 2022 being a better growing year. In 2022, USDA grade Jumbo roots were 10% numerically greater in SAA treated plots, than 25% PGF SAA 75% Drip Irrigation Fert. (DIF) and 9% over SAA and FAA. In 2023 there were similar trends, with USDA grade Number

Speakers

Brian Ward

Clemson University CREC

Co-authors

John Coffey

USDA

Karin Albornoz

Clemson University

Matt Horry

Clemson University

Matthew Cutulle

Clemson

Phillip Wadl

USDA, ARS, U.S. Vegetable Laboratory

Thursday September 26, 2024 2:45pm - 3:00pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

3:00pm HST

VCM 5 - The Effect of Potassium Fertilization on Potato Tuber Nutrition in the Columbia Basin of Oregon

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

South Pacific 1

Potato (Solanum tuberosum L.) crops require a high amount of potassium (K) to achieve the ideal yield and quality. However, the effect of K fertilization on potato tuber nutritional value is largely unknown. Based on the tubers from two-year field trials on a Quincy loamy fine sand soil in the Columbia Basin of Oregon, we evaluated yield, specific gravity, nutritional contents (i.e., ascorbic acid, tyrosine, chlorogenic acid, tryptophan, phenylalanine), and nutrient contents (nitrogen [N], phosphorus [P], K, and sulfur [S]) of three potato varieties (Clearwater Russet, Russet Burbank, and Umatilla Russet) under three K rates (0, 448, and 897 kg ha-1). Our results showed that the K application increased the yield of >170 g tubers but had no considerable effect on the total tuber yield. The application of K tended to decrease specific gravity regardless of varieties and years. Russet Burbank had the lowest specific gravity while Clearwater Russet had the highest one. Most of the nutritional contents were higher in 2020 than in 2021. Russet Burbank generally had the highest nutritional contents except for ascorbic acid compared to two other varieties. The application of K generally did not affect tuber nutritional contents but reduced the amounts of tyrosine in Clearwater Russet and Umatilla Russet in 2020. Fertilization of K resulted in an enhanced K content in the tuber, with the highest K application rate exhibiting a 35% increase in K compared to the control. However, it did not have any discernible effects on N, P, and S contents in the tubers. The tuber P and S were lower in Russet Burbank than other varieties. In general, there is no strong relationship between K fertilization and tuber nutritional contents.

Speakers

ruijun qin

OSU-HAREC

Co-authors

Aymeric Goyer

Oregon State University

Shahram Torabian

Virginia State University

Thursday September 26, 2024 3:00pm - 3:15pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

3:15pm HST

VCM 5 - Predicting Potato Tuber Yield Through Hyperspectral Signals and Machine Learning

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

South Pacific 1

Potato production is crucial for global food security, and with an increasing demand for food and a diminishing supply of fertile land, there is a need to boost production. Remote sensing technologies, such as high-resolution hyperspectral sensors, have the potential to provide valuable insights into potato growth, yield, and quality. Narrow spectral bands captured by these sensors are directly linked to biophysical parameters and can accurately estimate crop parameters. Recent studies have utilized hyper-spectral imagery acquired from proximal sensor such as ASD FieldSpec to estimate various crop parameters and yield. The results from these studies are promising, indicating that hyper-spectral sensors have the potential to improve crop management and agricultural practices. Moreover, the integration of remote sensing data with advanced analytical techniques, such as machine learning, helps in accurately estimating yield and yield components. In this study we are testing two machine learning such as PLSR and RF to predict biomass and N uptake in-season. Results from this indicate that PLSR performs better in predicting biomass and N uptake in potatoes. Moreover, yield can be best estimated at tuber bulking stage.

Speakers

Ravinder Singh

Graduate Research Assistant, UF

Co-authors

Gopal Kakani

Lakesh Sharma

University of Florida

Rajkaranbir Singh

University of Florida

Sehijpreet Kaur

Agronomy, UF

Simranpreet Sidhu

University of Florida

Thursday September 26, 2024 3:15pm - 3:30pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

3:30pm HST

VCM 5 - Evaluating King Stropharia Mushroom as an Intercrop in Asparagus and Tomato Production

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

South Pacific 1

Stropharia rugosoannulata (L.), the King Stropharia or Wine Cap mushroom, is a wood-loving fungus that grows well on organic mulches. Some vegetables can be successfully grown using organic mulches like woodchips or straw. As a result, farmers may be able to enhance their income by intercropping Stropharia mushrooms with their vegetable crops. However, no study has been identified that assesses this strategy's potential or effect on vegetable yields. Thus, a Stropharia-asparagus intercrop was evaluated by applying woodchips at three depths (4, 8, and 12 in), and a Stropharia-tomato intercrop was evaluated using woodchips, wheat straw, and soy straw (all at 6 in depth). Both experiments utilized a randomized complete block design (RCBD) with four replications and included bareground controls. The tomato study also included a positive mulch control using black plastic. In the fall of 2021, black plastic, inoculated wheat straw, and uninoculated soy straw and woodchip mulch provided earlier harvest than unmulched plots, while the soy treatments and bareground and black plastic controls increased total fruit numbers. In 2022, overall tomato production decreased, resulting in no marketable fruit. Across both 2022 and 2023 asparagus harvest began earlier with decreasing depths of mulch, and therefore lasted longer. Inoculated plots also produced more marketable spears than uninoculated plots. And, 12 in woodchip mulch significantly inhibited asparagus emergence and is therefore not recommended. These results suggest that a Stropharia-tomato intercrop may not be feasible without additional work, though a Stropharia-asparagus intercrop shows great promise. In fact, in 2023, mushrooms were observed in uninoculated plots demonstrating the gregarious growth of Stropharia in woodchip mulch on asparagus plots. The relative success in asparagus plots supports a need for further research to evaluate other Stropharia-vegetable [or fruit] intercrop candidates and/or strategies to improve compatibility.

Speakers

Olalekan Sipasi

Kansas State University

Sipasi Olalekan Ayodele is a Ph.D. Candidate at the Department of Horticulture and Natural Recourses at Kansas State University, ONE Champion 2017, Fellow Thinking School Africa, 2016 Winner of the African Youth Award in Agriculture, a seasoned NYSC SDGs Facilitator, The Future Award... Read More →

Co-authors

Calvin Liu

Kansas State University

Jeremy Cowan

Kansas State University

Thursday September 26, 2024 3:30pm - 3:45pm HST
South Pacific 1

Oral presentation (Individual talk), Vegetable Crops Management 5

SUBJECT Vegetable Crops

9:00am HST

Keynote Speaker: Kerry Kakazu

Friday September 27, 2024 9:00am - 9:45am HST

Coral 3

"Vertical Farming in Hawaiʻi: Design Considerations for our Unique Environment"

Kerry Kakazu, PhD is the President of MetroGrow Hawaii, the first vertical farm in the state. He has a masters and PhD in Plant Physiology from the University of California at Davis. After a career in academia doing research, teaching and administration he combined his interests in plant science, technology and the local food scene to create MetroGrow Hawaii in 2014. The farm has been providing premium leafy greens to local restaurants and gourmet markets since its founding and is now exploring ways to expand vertical farming to significantly increase food self-sufficiency and security in Hawaiʻi.

Speakers

Kerry Kakazu

Friday September 27, 2024 9:00am - 9:45am HST
Coral 3

Keynotes and Featured Sessions

SUBJECT Consumer Hort and Master Gardeners, Growth Chambers and CE, Vegetable Crops

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

11:15am 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

Oral presentation (Individual talk), Vegetable Crops Management 6

SUBJECT Vegetable Crops