ASHS 2024 Conference

Consumer Shopping Destination Preferences For Outdoor Garden Plants In The United States - Vivek Bist
Producer Awareness and Treatment of Ambrosia Beetle: Evidence from a Producer Survey - Ben Campbell
Consumer Awareness, Treatment Perception, and Purchasing Response to Flathead Borer - Ben Campbell
Market Research to Reinvigorate the Processed Vegetable Industry using Consumer Sensory Evaluations - Ann Colonna
Consumer Preferences for Commercially Available Poinsettia Cultivars in South Mississippi - Patricia Knight
Understanding the Characteristics of Ethnic Markets and Help Small Growers to Find Niche - ChyiLyi Liang
Consumers' WTP on Sustainability Turfgrass Attributes with Consideration of Aesthetic Attributes and Water Conservation Policies - Chanjin Chung

Outdoor garden plants are integral products in the nursery and garden stores industry in the United States. Industry reports indicate that home improvement centers and big-box stores pose a significant threat to small garden centers, nursery stores, and ornamental farmers through price competition while small local ornamental businesses tend to focus on personalized products and services to compete with chain retail stores. Identifying the key characteristics of consumer clusters that influence consumer shopping destination preferences can be useful for industry players to devise efficient marketing plans for their niche markets. This study employs cluster analysis techniques and multinomial logistic regression on the cross-sectional data collected from an online survey of 609 consumers to estimate the influence of consumer economic and socio-demographic characteristics on their shopping destination choices. The results from this study indicate that retail consumers of outdoor garden plants can be categorized broadly into four clusters: home improvement center shoppers (47.4%), big-box center shoppers (13.5%), local garden center shoppers (21.2%), and farmers’ market shoppers (17.9%). This study also finds that age, ethnicity, education, household income, number of children in the household, urbanicity, housing arrangements, and political inclination are useful predictors of shopping destination preferences for outdoor garden plants. This study adds valuable information to the market research literature for the retail ornamental horticulture industry.

Ambrosia beetles are creating a larger negative impact on tree crops throughout the U.S. As such, research is on-going to better understand ambrosia beetles and the impact of varying treatment methods. However, little is known about awareness and the treatments currently being utilized by producers throughout the U.S. This research takes an in-depth look at producer awareness, treatments utilized pre- and post-ambrosia beetle infestation, and expenditures associated with treating ambrosia beetles. Utilizing a survey of producers throughout the U.S., most producers were aware of ambrosia beetles; however, treatments to control ambrosia beetles varied considerably. Interestingly, many producers chose not to treat, which implies many producers currently do not see a positive benefit/cost to treat. A reason for lack of treatment could be the lack of consistency of ambrosia beetle infestations as many producers indicated ambrosia beetles were not a problem each year. Further, this research does provide stakeholders with information on what treatment methods are preferred and means to increase information dissemination about new ambrosia beetle treatments.

Flathead borers cause extensive damage for specialty crop producers throughout the U.S. As specialty crop producers attempt to mitigate damage, various treatments are being utilized. Furthermore, flathead borers cause damage in landscapes. To this end, this research examines the impact of consumer awareness and perception of flathead borer, consumer views on potential treatments in their landscape and in specialty crop production systems, and how the purchasing decision for a tree, bush, etc. might change given different probabilities of the tree, bush, etc. being impacted by flathead borer. An online survey on a representative sample of U.S. consumers conducted in 2024 found that there is little consumer awareness of flathead borer, but consumer’s recognized damage when shown pictures of what damage looked like. However, consumers had definitive opinions about flathead borer treatments, notably negative opinions about chemical treatments, though this view was heterogenous in nature. Finally, purchase decisions were impacted by the probability of a tree, bush, etc. being impacted, such that consumers were more accepting of a higher probability for minor damage, but a low probability of major damage would decrease the probability of purchase. From this research, stakeholders and researchers get a better understanding of which treatments may have a negative purchasing impact.

In an effort to understand perceived quality and purchase interest in processed frozen vegetables vs. their fresh counterparts, consumer sensory evaluations were conducted with Oregon consumers (n=108, 68% female, aged 18 and over). Consumers were served blind coded samples to investigate consumer preference for fresh vs. frozen select processed vegetables in appearance, aroma, color, overall liking, flavor, and texture. Utilizing hedonic scales and just-about-right methodology, consumers both rated their liking for each and assessed the ideal sweetness, texture, and moisture content. Additionally, the survey was used to probe the best strategies for increasing consumer awareness and marketability of processed vegetables and to understand consumer purchasing behavior and motivation when it relates to buying processed vegetables. Consumers also responded to questions about quality, purchase intent and ideal packaging size for processed vegetables. Consumer perception of frozen processed broccoli, while not as high as fresh, was positive. When asked about the characteristics of produce that most influence their purchasing decisions, quality and freshness were the two most important considerations to these consumers. Seventy-five percent responded either yes or depends on the price when probed about their interest in a frozen vegetable and fruit consumer supported agriculture (CSA) model. Consumers were also asked which reasons would most convince them to join a frozen vegetable and fruit CSA. The most frequently chosen options were 1) to support the livelihoods of growers and their communities, 2) frozen produce reduces waste and 3) frozen produce tastes fresher than off season produce. These ideas could be leveraged to encourage consumers to support the purchase of processed frozen vegetables as well as support a subscription service to high quality frozen produce.

Mississippi State University’s South Mississippi Branch Experiment Station began hosting a Poinsettia Open House in 2021. The goal of this event was to provide retail consumers and commercial producers with up-to-date information about poinsettias currently available for production. The first two events were single day events in early December (December 2, 2021 and December 1, 2022). Due to the success of the first two events, a decision was made to expand the event to two days in 2023 (December 1-2, 2023) and include educational presentations. Photography backdrops with poinsettia enhancements have been provided each year for anyone wishing to use them for Christmas card photos or to simply commemorate their visit. Attendees were given the opportunity to participate in several surveys at each open house. Participants completing a survey were allowed to choose and take home a poinsettia. Attendees were allowed to walk through the production greenhouse, view the poinsettia cultivars, and record their personal favorites. Participants viewed 35, 52, and 40 poinsettia cultivars in 2021, 2022, and 2023, respectively. In 2021, attendees identified Ice Punch, Orange Glow, Premium Ice Crystal, Superba New Glitter, and Autumn Leaves as their top five favorites. In 2022, attendees identified Superba New Glitter, Ice Punch, Norwin Orange, Prestige Maroon, and Grande Italia as their top five. In 2023, attendees identified J’Adore Soft Pink, Premium Picasso, Christmas Feelings Merlot, Christmas Spirit, and Tapestry as their top five.

Many small and socially disadvantaged producers grow fruit and vegetables. These farmers start small to satisfy family needs and support a preferred lifestyle. However, many small and socially disadvantaged farmers aim to be economically sustainable and want to create a feasible operation rooted in their communities. Since 2016, we have gathered information from over 3,000 small and socially disadvantaged farmers in the Southeastern region of the US who seek opportunities to improve wealth and health for individuals and communities. Information includes types of operations, family compositions, and needs of training and assistance. In particular, many of these farmers went through a series of experiential training programs to grow medicinal crops originated in Asia. These specialty fruit and vegetables are not familiar to most of the local farmers, and these specialty fruit and vegetables have high potential to serve as medicinal crops based on scientific studies. This presentation will introduce the components in this series of training linking production to market, financial assessment, risk evaluation, and niche opportunities to improve long-term health outcomes. The presentation will focus on connections and characteristics of ethnic markets, where most of these specialty fruit and vegetables are sold to diverse populations, from cultural and health perspectives. Market prices, consumer behaviors, and communication strategies will also be shared as examples to support small and socially disadvantaged farmers in breaking the barriers to access the ethnic market. Since 2016, this training program has assisted more than 1,000 producers to grow Asian medicinal crops, and successfully engaged in market activities serving diverse customers across the US.

This study estimates consumers’ willingness to pay (WTP) for sustainability turfgrass attributes such as low-input and stress-tolerance attributes, while considering potential trade-off relationships between aesthetic attributes and sustainability attributes. To address our objectives, our study conducts a choice experiment and estimates two mixed logit models. The first model includes low-input, winter kill, and shade-tolerance attributes as predictor variables, and the second model extends the first model by adding interaction terms between aesthetic and sustainability attributes. Another choice experiment is conducted under water policies with various water rate increase and watering restriction scenarios. Results from the mixed logit models show that overall, higher low-input cost reduction, less winter-damaged, and more shade-tolerance grasses are preferred, the direct effect of aesthetic attributes on consumers’ preference is strong, but the indirect effect represented by the interaction terms are generally statistically insignificant. Our results indicate that consumers like to have a pretty lawn, but no strong consideration is given to the aesthetics of their lawn when selecting low-input and stress-tolerance turfgrasses. Our choice experiment under water policy scenarios suggests that water pricing is more effective than watering restriction in increasing consumer demand for water-conserving turfgrasses. Our findings provide useful implications for future research in turfgrass breeding and evaluation of consumer preference for turfgrass. Many researchers have discussed potential degradation of aesthetic characteristics when developing input-saving turfgrass varieties. However, to the best of our knowledge, no earlier studies have investigated the effect of aesthetic deterioration caused by enhanced low-input and stress-tolerance attributed on consumers’ valuation of turfgrasses. Our findings suggest that aesthetic attributes need to be considered when conducting choice experiments for the valuation of the enhanced grasses, but limiting trade-offs may not be as important as enhancing low-input/stress-tolerance attributes when developing future turfgrasses. Another contribution might be the water policy outcomes from our choice experiment. Our experiment finds that the water pricing is more effective than the watering restriction in increasing consumer demand for water-conserving grasses, which could help develop better water policies in the future.

Identification of Genes Associated with the Chilling Prerequisites for Ripening in European Pear - Adwaita Parida
Effects of Cooling Delay and Harvest Maturity on ‘Gem’ Pear Internal Breakdown Development - Janet Turner
Efficacy of Ultraviolet Radiation for Control of the Mucor Rot Pathogen in Post-harvest Anjou and Bartlett Pears - Shawn McMurtrey
Preliminary Insights Into the Effects of Various Technologies of 1-methylcyclopropene (1-MCP) “AnsiP®” on Apple Fruit Quality During Shelf Life -William TC Chang
Pre-Storage Ambient Temperature Delay Reduces Lenticel Blotch by Mediating Metabolic Alteration in Cold-Stored ‘Summer Prince’ Apples - Hyowon Park
1-Methylcyclopropene from HarvestHold Fresh® impact on ‘Red Delicious’ apple during cold storage - Ozge Horzum

The pear (Pyrus communis L.) has been classified as a climacteric fruit, undergoing a ripening process characterized by a transition from system-I to system-II ethylene production. This transition denotes a change in the regulation of ethylene biosynthesis from being auto-inhibitory to auto-stimulatory process. Increased ethylene production during climacteric ripening is accompanied by a corresponding rise in respiration. Pears require chilling for ripening, and the duration of chilling necessary for ripening varies among cultivars. ‘Bartlett

‘Gem’ pear is a relatively new European pear cultivar with good fire blight resistance. Fruit can be eaten without ripening, either at harvest or upon removing from cold storage, when still crisp and juicy, or can be expected to ripen to a buttery melting texture after 30-60 days of regular-air (RA) storage (~30 °F). Although research initially indicated ‘Gem’ could be stored in RA conditions for 5 months with good quality retention, in practice ‘Gem’ storage has proved more challenging, primarily due to internal breakdown which can appear as early as 2 months after storage, either in RA or controlled atmosphere (CA) conditions. Additionally, with increasing commercial production of ‘Gem’, there is industry interest in extending storage beyond 5 months. This on-going study evaluates factors potentially influencing internal breakdown development, such as cooling delay (representing a delay of room temperature establishment at storage facility) and fruit maturity in year 1 and cooling delay and rate of controlled atmosphere (CA) establishment in year 2. In year 1, internal breakdown incidence was essentially absent for fruit harvested at 56 N flesh firmness but higher for fruit harvested at 44 N, especially where cooling was delayed. Fruit harvested at 56 N did not soften to below 18 N at 60 d storage, indicating a longer period of postharvest chilling is required for less mature fruit.

Mucor rot is caused by the pathogen Mucor piriformis, which can be responsible for severe post-harvest decay in a wide variety of commercially important fruit. There are a minimal number of fungicides that have been shown to be effective against Mucor rot. As a result, alternative methods for control of Mucor rot are currently being investigated. Ultraviolet light in the C spectrum (UV-C) is a germicidal form of radiation that has been demonstrated to kill common post-harvest pathogens. Little information is available for the effectiveness of UV-C light against M. piriformis. For this study, a Far-UV light (222-nm) and a UV-C light (265-nm) were tested for their ability to inactivate M. piriformis. The effects of three UV-C light treatments (0kJ, 10kJ, and 20kJ) were tested on Anjou and Bartlett pears that had been wound inoculated with M. piriformis. Lesion sizes were measured after five weeks in cold storage. The optimal dose required to inactivate M. piriformis in vitro in polystyrene wells with the Far-UV light was found to be 9 kJ, which, with available bulbs set at 8 cm distance, required 17 minutes of treatment. Results showed no significant effect of treatment on final lesion size for both the Far-UV light and the UV-C light. For both lights, final mean lesion sizes were larger for fruit that had been treated with the 20kJ and 10 kJ treatments when compared to the control fruit that received no UV-C treatment. Results from this study suggest that UV-C radiation in the 222-nm and 265-nm light spectrum have minimal impacts on reducing rot caused by M. piriformis in Anjou and Bartlett pears, and, given the duration of treatment required for spore deactivation, this technology may prove impractical for managing M. piriformis on other components of pear packing systems.

Various postharvest formulations of 1-MCP have been innovated to optimize its efficacy for repeated use across storage, transportation, and retail stages. For small farms or fruits destined for farmers' markets, utilizing postharvest technologies with minimal 1-MCP concentrations is pivotal. In this trial, fruit from ‘Empire’, ‘Red Delicious’, and ‘RubyFrost’ apples was obtained from Cornell orchards in Lansing NY and Cornell AgriTech orchards in Geneva NY, on October 1, 4, and 13, respectively. Fruit were transported to the postharvest laboratory at Cornell University in Ithaca NY and fruit maturity indices were assessed. After cooling the fruit overnight, three different formulations of 1-MCP (tablet - AnsiP®-G, sticker - AnsiP®-Sticker, and sheet - AnsiP®-S, LYTONE Enterprise, Inc., Taiwan) were tested. The treatments were applied to fruit packed in cardboard boxes (30×30×48 cm), each containing 4 trays, at 3 °C for 24 hours. Fruit were then transferred to 20 ⁰C for 4 weeks, and fruit quality including internal ethylene concentration (IEC), flesh firmness, soluble solid content, titratable acidity, fruit color, IAD value index for peel chlorophyll content, and fruit weight were assessed weekly. Additionally, the release dynamics of 1-MCP from tablets, stickers, and sheets were evaluated in different trial. The 1-MCP tablets outperformed other treatments in reducing IEC and maintaining fruit firmness. The effects of different 1-MCP technologies on apple fruit quality and longevity during shelf life will be discussed.

Lenticel blotch as peel physiological disorder occurs in cold-stored apple fruit, characterized by irregular shape breakdown tissue without extending to the flesh. This study aimed to evaluate the postharvest treatment effects on fruit quality attributes, mineral nutrients, targeted metabolites, and incidence of lenticel blotch, and their relationship in cold stored ‘Summer Prince’ apple fruit. Fruits were harvested from 2 orchards, treated with postharvest 1-MCP, pre-storage ambient temperature delay for 7 days (ATC), and 1-MCP ATC at harvest and then stored at 0.5 °C for 5 months. There were significant differences in the organic matter content, nitrate nitrogen (NO3-N), and phosphoric acid contents in the soil. Calcium, manganese, copper, and zinc in leaf tissues were significantly different between 2 orchards. Lenticel blotch was effectively controlled by ATC treatment, while exacerbated by 1-MCP. Based on the results of VIP scores, histidine, valine, sucrose, K/Ca ratio, (K Mg P)/Ca ratio, total phenolic compounds, total flavonoids, ABTS, and DPPH were influenced by the postharvest treatments. In the results of volcano plot analysis, ATC treatment effectively controlled the symptoms and up-regulated in amino acids, such as valine, histidine, proline, and isoleucine. However, 1-MCP treatment caused to induce lenticel blotch by upregulating aspartic acid and glutamic acid. Therefore, the results indicated that pre-storage ambient temperature delay should control the lenticel blotch by mediating targeted metabolic alteration during cold storage.

Ethylene affects the postharvest quality and storage life by affecting the physiological changes related to ripening in apple fruits. 1-Methylcyclopropene (1-MCP), a cyclopropane-derived compound, is an effective ethylene inhibitor that blocks ethylene receptors at the cellular level, preventing ethylene effects and delaying its production. Several commercial products are available that provide controlled release of 1-MCP. In this study, a new 1-MCP technology was used, which uses a polymer sheeting material coated with cyclodextrin-encapsulated 1-MCP that is released when exposed to high humidity. Red Delicious apples were commercially harvested in Elbridge, Michigan, and 1-MCP sheets were applied targeting different 1-MCP concentrations (50, 100, 1000, 4000 ppb) and were placed on top of the fruit held in vented cardboard apple boxes in an open room. Another commercial 1-MCP product, Easyfresh®, powder (EF), (Fine Americas, Walnut Creek, CA) was applied at multiple dosages (0, 5, 50, 100, 1000 ppb) to fruit in cardboard apple boxes within sealed chambers as controls. Treated and untreated apples were stored in a cold room at 0 °C temperature and >90% relative humidity. We examined changes in ethylene production, respiration rate, firmness, soluble solids, titratable acidity, weight loss, and superficial scald during 7 months cold storage. The EF treatment was more effective than the 1-MCP sheet treatment for a given target concentration. The effect of 4000 ppb 1-MCP sheet was similar to the 50 ppb EF for the first 3 months of cold storage. The lack of effectiveness of the 1-MCP from sheet was likely due to escape of the 1-MCP from the apple box and off-target sorption by the cardboard.  EF 100 and 1000 ppb concentrations resulted in the lowest ethylene production, respiration rate, weight loss, and superficial scald values in the overall study for 6 months. These concentrations were also influential in preserving firmness, brix, and titratable acidity values. 1-MCP sheet efficacy could be improved by raising the dosage target or changing the architecture and the materials of the boxes in which treatment occurred.

Microgreens are an emerging functional food that is sought after due to dense nutrient compositions as well as vibrant colors and textures. Seed contamination is one of the major food safety concerns as microgreens are consumed raw. Plant pathogenic diseases are also a concern as these can cause a reduction in the growth and quality of the crop. Seed sanitation methods should effectively reduce microbial load with minimal adverse effects on seed germination. The objective of this study was to investigate the effect of four seed sanitizing treatments on germination, shoot production and mineral nutrient concentrations of four microgreen species including chive (Allium schoenoprasum), shiso (Perilla frutescens var. crispa), scallion (Allium fistulosum) and dill (Anethum graveolens). Microgreen seeds were subject to four sanitizing treatments including: Tsunami 100 (400 ppm, 5 min), hydrogen peroxide (3%, 5 min), vinegar (1%, 15 min), and hot water (85°C, 10 sec). Seeds which were treated with deionized water for 10 min were considered to be the control. The microgreens were grown in a greenhouse and were planted into a peat-based substrate and a jute fiber mat in January 2024. Prior to greenhouse production, a germination test was conducted to investigate germination percentage of seeds for each species in response to the four sanitizing treatments or control. Microgreens were assessed for germination, shoot coverage, shoot height, fresh and dry shoot weight, and mineral nutrient concentrations. There was a significant interaction between microgreen species and the sanitizing treatment on fresh and dry shoot weight. The lowest fresh shoot weight for the three species chive, scallion and shiso was 938.2 g·m-2, 976 g·m-2, 907.8 g·m-2, respectively when treated with hot water, with the other three sanitizing treatments and control resulting in statistically similar fresh shoot weights. Dill microgreens showed little difference in fresh shoot weight among the five sanitizing treatments with values ranging from 506.4 g·m-2 in hot water to 868.2 g·m-2 in control. Sanitizing treatment and substrate type both had a significant effect on the shoot height of tested microgreens. Hot water treated microgreens produced the shortest shoots with a mean shoot height of 7.7 cm regardless of species or substrate type. The other four sanitizing treatments produced statistically similar shoot heights ranging from 8.01 cm with vinegar to 8.1 cm with Tsunami 100. The peat substrate increased overall shoot length in tested microgreens compared with jute fiber mats regardless of sanitizing treatment or species.

There are over 7,500 apple varieties grown worldwide, each with its own set of organoleptic characteristics such as flavor, texture, and appearance. However, no more than 150 varieties have been introduced broadly in the global market. Consumer preference for apples is influenced by a complex interplay of factors beyond taste. The sheer variety of apples available in the market creates a valuable opportunity for a digital app that can help consumers navigate and select the best options based on their quality trait preferences. This project, in cooperation with U.S. Apple Association, aims to ultimately develop a digital app that will recommend apple varieties based on consumer’s preferences regarding sweetness, sourness, juiciness, crispiness, flavor, color, texture, and nutrition content. Thus, we examined the relationship between various sensory and physico-chemical data to understand their significance in apple selection. Five cultivars of apples grown organically (‘Ambrosia’, ‘Cosmic Crisp’, ‘Gala’, “Sugar Bee®’, and ‘Sweet Tango’) were purchased from a retail store in Mid Atlantic area during the winter season. Thirty apples of each cultivar (n=30) were measured for volume, weight, height, width, specific density, surface area, circumference, fizziness and for skin color (L*, a*, b*, hue angle, chroma). Firmness parameters and acoustic texture parameters were also measured. Additionally, total juice content, soluble solid content (SSC), titratable acidity and pH were assessed. Consumer panels (n=45: female=22, male=23) were conducted to evaluate traits including sweetness, sourness, flavor, texture/mouth feel, and overall eating quality (OEQ) using a five-point scale. Consumers displayed a stronger preference for ‘Cosmic Crisp’ and ‘Sugar Bee®’ varieties compared to ‘Gala’ and ‘Ambrosia’. This preference is driven by significantly higher consumer ratings for firmness, sweetness, and sourness of ‘Cosmic Crisp’ and ‘Sugar Bee®’. As highlighted in previous studies, correlations between consumer-rated sensory scores and their corresponding instrumental measurements were low. Furthermore, OEQ showed a stronger correlation with sensory ratings (r=0.54-0.84 ) than instrumental measurements (r=0.02 to 0.49). This suggests that consumer evaluation is critical, and may be a more reliable indicator, for the development of a digital app, compared to instrumental measurements. An accompanying consumer survey (n=30) indicated that crispness is a key factor considered by consumers when choosing apples. This project provided valuable insights and potential issues when developing a user-friendly app for consumers. It identified the dominant factors influencing apple selection and showed methods to cross-validate sensory ratings with corresponding instrumental measurements.

Visual quality is an important factor for consumer purchasing decisions of fresh-cut lettuce. Consumer behavior towards produce quality has been studied via traditional human evaluations. For sensory studies, quality evaluations are commonly done by trained human panels and consumer panels. This study was to investigate the possibility of replacing human evaluation with a machine based approach, using image capturing and analysis, and determine whether efficiency of produce quality analysis can be enhanced. Three types of data were collected: (a) consumers’(n=200) evaluation of lettuce on the picture, (b) instrumental analysis of samples (package head-space gas composition (O2, CO2) and electrolyte leakage), (c) image analysis of lettuce on the pictures. For image analysis, ImagePro’s smart segment tool was used to classify the lettuce samples into five regions: adult leaf, baby leaf, rib, rib degradation, and leaf degradation. This was used to find and calculate L*a*b, hue angle, chroma values, area, and relative area of these regions. Lettuce samples consisted of four cultivars (Green Forest, King Henry, Parris Island Cos, PI 491224). Samples were measured on day 7, 10, and 13 of storage. To predict browning score, data sets (b) and (c) were fed into a regression algorithm. The scores assigned by trained panels served as the target variables. The results showed a strong correlation between consumer’s browning score on the pictures and predicted scores generated by the regression model (r=0.74). Interestingly, removing the instrumental data set (b) did not worsen the model’s performance. The model achieved an R2 of 0.92 and RASE of 8.90 when using trained data sets (a) and (c), and an R2 of 0.91 and RASE of 8.53 when using trained data set (c) only. While a correlation coefficient of 0.74 indicates a promising relationship between image analysis and human evaluation of browning score, it’s not sufficient to definitively replace human evaluation. Further studies with larger datasets and exploration of more advanced machine learning models could lead to a more robust statistical model.

Quantitative and Qualitative Characteristics of High Quality Cannabis Sativa - Matthew Taylor
A Three-state Summary on the Critical Weed Free Period for Transplanted Floral Hemp. - Harlene HattermanValenti
Impact of Cover Crops on Weed Pressure and Soil Health in No-till Fiber Hemp Production - Ashlee George
Photoperiod Sensitive CBD Hemp Response to Fertigation Nitrogen Inputs in a Raised-bed Plasticulture Growing System - Francesco Di Gioia
Heavy Metal Application Timing Impacts Plant Growth in Cannabis sativa - Harrison Meekins
Field Evaluation of Controlled Release Fertilizer in Support of Best Management Practices for Industrial Hemp in Florida - Shea Keene

Scientific research activities focused on production of high-quality Cannabis sativa continue to grow in both the industry and academic sectors. At the university level in the United States, the majority of the research uses hemp-type or low tetrahydrocannabinolic acid (THCa) cannabis cultivars due to federal restrictions. Only at the industry level and in states with some level of medical or recreational legalization can production research be carried out on high THCa or drug-type Cannabis. Dried female flower inflorescences are the harvested and saleable portion of the Cannabis plant. The quantitative traits of flowers are relatively clear and easily enumerated. To be considered superior quality, THCa concentration should be 25% or greater and the total terpene concentration should be 2% or greater on a dry weight basis (moisture content of 10-12%). While the average cannabis consumer values these characteristics, they also greatly appreciate many of the qualitative characteristics of cannabis flower, which include visual appearance or sometimes referred to as bag appeal, olfactory characteristics when opening the container of cannabis and while breaking apart the flowers, texture, and taste when smoking. These characteristics are more difficult to define and quantify. When conducting research, both quantitative and qualitative characteristics need to be of great consideration when the goal is to produce high quality Cannabis flower.

There is a growing demand for hemp-derived products but because of the crop's criminalization history, there is limited University-produced information describing best production practices. The research objective was to define the critical weed-free period (CWFP) for transplanted floral hemp. Field trials were conducted in 2022 and 2023 at an outlying NDSU Agriculture Experiment Station near Prosper, ND (46.57° N, 97.01° W), the Cornell AgriTech campus in Geneva (42.88°N, 77.01°W), and the Clemson University Coastal Research and Education Center (33.46°N, 79.55°W). Four cultivars were transplanted at NY with three cultivars (Bubbatonic, Sour Space Candy, and Quick Spectrum) in common with ND. Three cultivars were transplanted in SC with two cultivars (Cherry Wine and Bubbatonic) in common with NY. The CWFP treatments were weeded for 0, 1, 2, 4 and 6 weeks, and weed-free. Weeding was accomplished by manually hoeing and hand-weeding. Weed species varied at each location but were mainly annual weed species (both broadleaf and grasses). Plants were harvested after at least a 16-week period in the field and air-dried before removing leaf and floral biomass from stems. At SC, when averaged across cultivars and trial years, a significant increase in mean floral yield with 2, 4, 6, and season long weed-free intervals when compared to 0 weeks weed-free. In addition, a significant decrease in dry weed biomass existed when comparing the same weed-free intervals to the 0 weeks weed-free treatment. At NY, hemp biomass averaged across all cultivars was significantly affected by the duration of weed competition. Per plant yields were reduced >80% when weeds were allowed to compete almost season-long. Biomass production was maximized when weeds were suppressed for at least 6 weeks after transplanting. At ND, results were quite different due to timely rainfall and lack of rain. Under adequate to excellent moisture conditions, the stem diameter, stem number, plant weight:height ratio, and dry biomass yield responses were significantly different only when weed control was provided for one week. However, under extreme season long drought conditions, stem diameter increased 53%, weight:stem ratio increased 172% and dry biomass increased 201% when weeds were controlled the entire season. Results indicate that transplanted hemp is sensitive to competition and preventing weed establishment for several weeks was necessary to reduce competitive interactions. Results also suggested that the need for a weed-free period was exacerbated and most important when rainfall during the growing season was limited.

Current fiber hemp (Cannabis sativa <0.30% total THC) production systems rely on pre-emergent herbicides to manage weeds prior to canopy closure. Due to the rapid growth of fiber hemp, paired with the plastic nature of the crop, the need for weed suppression is most critical in the first month after planting. No-till systems with a rolled cover crop residue may be able to provide weed suppression without the use of herbicides, which can lower the cost of inputs, reduce the risk of negative environmental impacts associated with herbicide use, and improve soil health. Four cover crops - crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa), cereal rye (Secale cereale), and triticale (xTriticale)- were roller-crimped into a mulch, and fiber hemp was no-till drilled into the residue. Each cover crop plot was paired with two bare ground plots, one of which was weeded weekly, while the other remained weedy. This design was repeated in three locations in the coastal-plain region of North Carolina (Kinston, Clinton, and Goldsboro). Crop emergence, weed counts and biomass, and fiber hemp biomass and yield were measured in each plot. Cover crop biomass was measured before planting and after retting to determine whether this residue may be a potential contaminant during baling. Soil health parameters were compared among cover and bare plots. Hairy vetch resulted in greater hemp emergence in Kinston, but emergence was not affected by the mulches otherwise. Hairy vetch plots had less weeds than others in Clinton and Goldsboro. Soil respiration and potentially oxidizable carbon did not differ by treatment, with the exception of higher soil respiration in grass covers in Goldsboro. Cover crop biomass remaining after retting was higher in grass plots than legume plots, indicating a potential for bail contamination. These preliminary results indicate that fiber hemp can be grown in a no-till system.

Cannabis sativa is a known hyperaccumulator of heavy metals (HM), and testing of hemp medicinal products is required for HM contaminants including arsenic (As), cadmium (Cd), and lead (Pb). The objective was to evaluate how the timing of HM applications impacts hemp growth. A plant experiment was conducted where 40 Cannabis sativa ‘Wife’ hemp plants were grown in deep water culture systems in a growth chamber. Aqueous nutrient solutions including combined As, Cd, and Pb were applied directly into the hydroponic solution on a weekly basis, with HM concentrations of 0.0, 0.5, and 1.0 mg HM/L. During the first six weeks, plants were grown under long days to promote vegetative growth, and 15 plants were harvested at the end of this vegetative growth phase. The remaining 25 plants were grown under short days to initiate flowering, with harvest 6 weeks later. Total dry mass (P < 0.05), shoot dry mass (P < 0.05), and root dry mass (P < 0.01) were significantly affected by HM application timing. The total and shoot dry mass was the highest for the control group, followed by the plants that received HM at 0.5 or 1.0 mg/L during the reproductive phase, and the least growth occurred in plants that received HM at 0.5 or 1.0 mg/L during the vegetative phase. Root dry mass decreased as HM concentration increased (P < 0.05). Flower dry mass was not significantly affected by HM application timing or concentration. Results highlight how exposure to HM at 0.5 to 1.0 mg/L markedly reduce biomass accumulation, especially when exposure occurs early in the production cycle.

Nitrogen (N) fertilization plays a key role in determining the productivity and quality of horticultural crops and limited information is available on the N requirements of photoperiod-sensitive CBD hemp (Cannabis sativa L.). With the objective of providing recommendations on N fertilization to CBD hemp growers a field study was conducted in Pennsylvania to evaluate the response to N inputs of two photoperiod sensitive CBD hemp genetic resources: a clone named ‘FunDip’ (The Hemp Mine) propagated using rooted cuttings and ‘Sour Kush’ (Kayagene) propagated using feminized seeds. Both selections were planted mid-June on raised beds mulched with black polyethylene film and served by drip irrigation. Plants were established at 1.5-m in-row and 2.4-m between rows. After planting both CBD hemp selections were fertigated weekly with urea (46-0-0) using seasonal application rates equivalent of 84, 168, 252, and 336 kg/ha of N. An unfertilized control was used to account for the N available through the soil and to estimate the crop N use efficiency. Treatments were arranged according to a split plot experimental design with four replications. Nitrogen treatments were randomized within the main plots while hemp selections were randomized within subplots. Each experimental unit had a minimum of 12 plants, unfertilized border rows and in-row areas were used as buffer zones to avoid fertilizer cross-contamination between different N applications rates. Plant response to N inputs was evaluated conducting biometric assessments during the growing season and at final harvest. Representative plants were sampled to measure leaf and inflorescence, stem, and total plant fresh and dry biomass. Oven-dried plant tissue samples were analyzed for their total N content to estimate the plant N accumulation during the growing season. At every biometric assessment, soil samples were collected and analyzed for pH, EC, and nitrate (NO3-) content. A quadratic response to N inputs was observed in both selections. At final harvest, the total fresh plant biomass of both genotypes was maximized with the application of 252 kg/ha of N and declined at higher N rate. However, no increase in plant dry biomass were observed in plants fertigated with over 168 kg/ha of N in both genotypes. An accumulation of NO3-N and associated increase in EC was observed with the progression of the growing seasons especially in plots fertigated with over 84-168 kg/ha of N, in Sour Kush and FunDip, respectively, which suggest an excess of N was applied with N rates exceeding 84-168 kg/ha.

Successful field cultivation of hemp (Cannabis sativa L.) in Florida is restricted to summer months when rainfall is highest, as hemp is exceptionally sensitive to daylength. Given the prevalence of soils in Florida with poor nutrient and water holding capacities, controlled release fertilizer (CRF) could be ideally suited for outdoor cultivation due to its slow-release profile. To assess the effectiveness of CRF to support plant growth while minimizing water quality risks, the plant growth and biomass production of four hemp cultivars (‘Wife’, ‘Sunset Improved’, ‘FunDip’, and ‘Belle’) were evaluated in response to nitrogen and phosphorous availability from ten CRF formulations in Apopka, Florida during the summer of 2023. Plant growth was assessed post-transplant and monthly thereafter until harvest by measuring the height, widest width, and width perpendicular to the widest width of each hemp plant. At harvest, plants were severed at the soil surface and dried at 70 degrees Celsius for three days. For each plant, the total plant biomass and total flower biomass was measured. Significant differences in plant growth and biomass production were found among varieties; however, minimal differences were found in plant growth and biomass production within variety in response to varying CRF formulations. These results suggest that CRF can provide adequate levels of fertility for the growth and development of hemp cultivated outdoors in Florida, and that selection of hemp cultivar affects plant growth and yield.

ASHS Intellectual Property Interest Group Session
Proposal Proposed by: Fruit Breeding Interest Group and Intellectual Property Interest Group

Plant intellectual property is an important topic for plant breeders, universities and private companies who handle the release and exchange of plant materials. On the one hand, properly protecting new cultivars is critical to protect the genetic integrity of the genotype and credit the developer. On the other hand, understanding the types of intellectual property laws relevant to plants is important for breeders/researchers to exchange materials for collaborative evaluation and development. Therefore, this interest group session will focus on plant intellectual protection and material transfer. We will invite speakers from public and private plant breeding programs as well as experts on intellectual property laws to share their knowledge and advice on following areas: Domestic plant protection, International plant protection, Domestic plant material transfer, and International plant material transfer. The topic of intellectual property was voted by members of both interest groups (Fruit Breeding Interest Group and Intellectual Property Interest Group) as a high priority area. This session will greatly benefit plant breeders, researchers, and intellectual property officers.

Coordinator(s)

• Sushan Ru, Auburn University, Auburn, United States
  
  Moderator(s)
• Julia Harshman, Duda Farm Fresh Foods, United States
  
  

Speakers/Participant(s) (15 minutes talk, 5 minutes Q & A)
4:00 – 4:10 pm Introduction and Welcome & Presenting the Outstanding Fruit Cultivar Award

4:10 – 4:30 pm Matthew Clark, Associate Professor & Apple and grape Breeder, University of Minnesota

4:30 – 4:50 pm Neil Anderson, Professor & Ornamental Crop Breeder, University of Minnesota

4:50 – 5:10 pm Fred Gmitter Professor & Citrus Breeder, University of Florida
Title: University of Florida Citrus Breeding Team Experiences and Lessons in IP Management.

5:10 – 5:30 pm Megan Bowman, Corporate Patent and Trademark Lead at Ball Horticultural Company
Title: Intellectual Property in Horticulture: Industry Insights

5:30 – 5: 40 pm David Karp, University of California, Riverside.
David will likely give a summary of his talk on Pomological Nomenclature: Recent Developments and Problems.

5:40 - 6:00 pm Group discussion