ASHS 2025 Conference

Open to all attendees.

American elderberry (Sambucus nigra subspecies canadensis) is native to much of North America. The fruit are soft, small, intensely purple drupes, containing three to five seeds. Berries exhibit some anti-viral properties and were found to slow the progression of dementia in animal studies. European elderberries (Sambucus nigra subspecies nigra) have long been used to make phytochemical-rich value-added products, in contrast to the underutilized American subspecies. American elderberry offers potential for products with more color stability as the berries have more cyanidin-3-sambuboside-5-glucoside and acylated anthocyanins than European elderberry. Developing innovative, cost effective, concentrated and portable products such as powders are desired for creating value added products. Successful microencapsulation of elderberry into powders was achieved by spray drying elderberry juice or pomace extract with soy protein isolate or tapioca starch as drying carriers. Anthocyanin profiles in the encapsulated powders were similar to those in juice but concentration was increased by 3-fold. Acylated anthocyanins made up 77% and cyanidin-3-sambuboside-5-glucoside, 17% of the total anthocyanins. Flavonoids delivered in powders encapsulated with soy protein concentrate were doubled in bioaccessibility compared to juice. Fermentation of juice with Saccharomyces cerevisiae yeast decreased soluble sugars and increased spray drying efficiency 20-25%. Fermented elderberry juice spray dried with pea protein or yeast as drying carriers showed increased phenolic content and bioaccessibility. This production strategy offers an efficient way to deliver stable, phytochemically enriched, value-added products from American elderberry for multiple food applications.

Texas has a strong history in fruit crop production, supported by its range of climates, soil types, and a long record of innovation. Grape growing began in the 1600s with Spanish missionaries and became globally important thanks to T.V. Munson, a horticulturist from Denison, Texas. His work in rootstock breeding helped save European vineyards during the phylloxera crisis. Today, Texas is a major producer of grapes, as well as pecans, peaches, citrus, and many small fruits. These crops all face challenges related to extreme weather events, soil conditions, and long-term sustainability. To help address these issues, the Horticultural Crop Physiology program at Texas A

The table grape cultivar ‘Concord Seedless’ is adapted to the northeastern U.S., but small berry size, poorly filled clusters, shot berries, and low marketable yields has hindered its’ commercial potential. Gibberellic acid (GA3) is a plant growth regulator widely used in viticulture to reduce fruit set and to increase cluster length, cluster weight, and berry weight, but effects vary depending on cultivar, application timing and rate. We evaluated the effects of GA3 on cluster quality in ‘Concord Seedless’, a cold-hardy table grape cultivar, grown using two training systems: Munson and Vertical Shoot Positioning (VSP). Field experiments were conducted in 2023 and 2024 at the UNH Horticultural Research Farm in Durham, NH. Treatments included four concentrations of GA3 applied pre-bloom (0, 21, 42, and 63 mg/L) and one concentration post-bloom (0 and 50 mg/L), in a 4 × 2 factorial arrangement. A split-plot design with four blocks was used, with training system as the main plot and GA3 treatments as subplots. The experimental unit for sub plot was two adjacent shoots; all treatments were applied on a single vine. We measured cluster weight, frequency of shot berries and thinned berries, and percentage of clusters exhibiting curling. We hypothesized that pre-bloom GA3 application would result in cluster elongation and that post-bloom GA3 application would increase cluster and berry weight. We also hypothesized that GA3 application at either time would reduce the incidence of shot berries. Results showed significant year × GA3 interactions. In both years, cluster weight was higher in Munson than in VSP-trained vines, but there was a significant interaction between training systems and GA3 treatments in 2023. VSP-trained vines had a higher frequency of shot berries and thinned berries in both years, but the effect was not significantly different. In both years, pre-bloom GA3 applications reduced cluster weight and induced cluster curling and excessive berry thinning, which made clusters unmarketable. In 2023, post-bloom application (50 mg/L) increased cluster weight, and did not cause berry thinning or cluster curling in either training system. Our findings suggest that a single application of post-bloom GA3 when berries are 6 to 9 mm in diameter can improve cluster quality in ‘Concord Seedless’ under cold-climate conditions.

Aronia berry, also known as chokeberry, are rich in antioxidants that promote cardiovascular health, immune function and overall well-being. Beyond their nutritional benefits, they also serve as attractive ornamental landscape plants, providing wildlife provisioning and contributing to ecosystem services. However, not much is currently known about the plant growth and fruit quality of aronia berry in the southeastern US, and how different regions may affect plant growth characteristics. The main objective of this study was to establish plantings in two locations in Georgia and assess native aronia species for plant growth and fruit quality characteristics. The growth and yield of two native species, black chokeberry (Aronia melanocarpa) and red chokeberry (Aronia arbutifolia), were assessed during the 2024 growing season at two agroecological regions in Georgia: Blairsville (Zone 7a, Blue Ridge region) and Griffin (Zone 8a, Piedmont region). Field plots, consisting of three-year-old plants, were established at both locations in 2021. Plant measurements included: growth index, stem diameter at 100 cm height, yield (kg), berry size of the equator (mm), berry weight (g), dry berry weight (g), total soluble solids (°Brix), pH, and total titratable acidity (%TTA). Black chokeberry exhibited significantly higher values (p ≤0.05) for growth and yield in Blairsville than in Griffin. Total soluble solids were not different across locations. Similarly, red chokeberry had higher growth index, stem diameter, and yield in Blairsville, yet location had no effect on berry weight. Individual berry size was not affected by location for both black and red chokeberry. These findings suggest that even within adjacent eco-regions, aronia species show different growth and berry production, and that plants grown in northern regions exhibit larger size and bear more berries. This has implications for ornamental landscapes and restoration habitat practices. This work will be used as part of a larger work to examine the potential of aronia as an alternative fruit crop in the southeast.

The integration of solar energy production with agriculture, known as agrivoltaics, presents a promising solution to address land-use competition while boosting perennial crop productivity. This study evaluated the feasibility and impact of agrivoltaic systems on strawberry (Fragaria × ananassa) production in Iowa. The objectives included assessing plant growth, fruit yield and quality, microclimatic modifications, and economic viability under photovoltaic (PV) panel shading. We hypothesized that partial shading from PV panels would mitigate heat stress, reduce water demand, and enhance fruit quality without significantly compromising yield. A replicated field trial of two June-bearing strawberry cultivars in 2024 and 2025 compared plants under a standard rotating 5-ft PV configuration with traditional open-field production. Environmental parameters such as light intensity and temperature were monitored to quantify microclimatic changes. Additionally, plant physiological responses and post-harvest disease incidence were analyzed. Future economic assessments will determine profitability and trade-offs associated with energy co-production. Findings from this research informed best management practices for integrating agrivoltaics in specialty crop production, particularly in temperate regions. In 2024, berries were larger in weight and size under the panels compared to the open-field plots. Post-harvest assessment indicated that the increase in size did not correlate with a reduced shelf life. Overall, this study found a favorable effect of intermittent shading on strawberry production in the Midwest.

This study presents the outcomes of the NE-SARE Professional Development Program, which was designed to enhance the capacity of farmers and agricultural service providers in the area of nutrition management for June Bearer (JB) and Day Neutral Strawberry (DNS) cultivars. Through seven targeted workshops including the UMES Small Farm Conference and the NE-SARE workshop on fertilizer strategies participants gained practical skills in fertilizer injector use, dose calculations, and the benefits of liquid vs. granular fertilizers. A total of 87 participants attended, with 82 identifying as Black and 46 as women. Key innovations included the distribution of over $7,000 worth of strawberry plants, overcoming access barriers for small-scale and BIPOC growers. Educational sessions transformed participant confidence, with post-survey data showing a shift from 40% reporting "no knowledge" to 70% achieving "advanced" proficiency in nutrition management. Participants reported the ability to perform fertilization calculations, use injectors, and understand fertilizer types. These workshops promoted sustainable practices by encouraging injector-based applications to reduce nutrient loss and pollution. This initiative not only advanced technical knowledge but also equipped growers to make environmentally sound, cost-effective decisions tailored to their operations. The outcomes reveal increased regional engagement and strengthened capacity among underserved farmers, empowering them to adopt sustainable techniques in strawberry cultivation on the Delmarva Peninsula.

Growing southern highbush blueberries (SHB, Vaccinium corymbosum interspecific hybrids) in Florida’s sandy soils presents significant challenges due to their low water retention and limited fertility. Milled pine bark is a widely used soil amendment for SHB cultivation, as it enhances moisture retention, nutrient-holding capacity, soil structure, and maintains an optimal pH (approximately 4.0–5.0) for the crop. However, the physical and chemical characteristics of pine bark, particularly its decomposition dynamics within the SHB rhizosphere, remain poorly understood. This study investigates how pine bark decomposition affects SHB plant growth and productivity. SHB cultivars ‘Optimus’ and ‘Farthing’ were grown in raised beds amended with either aged or fresh pine bark. Plants were irrigated and fertigated via a drip system following commercial production practices. Beginning in June 2024, we measured plant volume, vertically projected leaf area, leaf nutrient concentrations, and yield. In addition, soil and pine bark samples were collected and analyzed. Our findings indicate that plants grown in aged pine bark produced greater above-ground biomass and exhibited higher macronutrient concentrations than those grown in fresh pine bark. The carbon-to-nitrogen (C:N) ratio differed between treatments at the start of the experiment, but fresh pine bark has changed more than aged pine bark since the start of the experiment. These results suggest that fresh pine bark may immobilize nutrients in the SHB rhizosphere, limiting plant growth. A deeper understanding of pine bark decomposition in SHB farms will support the development of sustainable fertilization strategies and improve long-term plant health and productivity.

Blueberries (Vaccinium species) belong to the Ericaceae family and are recognized for their antioxidant content and associated health-promoting properties. A key challenge in blueberry production is their asynchronous ripening with fruits on the same plant often maturing at different times. This leads to multiple harvests, increased production costs, and reduced overall fruit quality. Fruit ripening is a coordinated process wherein there is an increase in sugar concentration, decrease in acidity and accumulation of pigments such as anthocyanins. Blueberry fruit are classified as exhibiting atypical ripening behavior with an increase in respiration and ethylene during ripening. However, ethylene production is not autocatalytic and is under developmental regulation. Previous work from blueberry and other fruits have suggested a role of other hormones such as abscisic acid (ABA), auxin and jasmonates in fruit ripening. In this study, the cultivar Powderblue (Vaccinium ashei) was used to characterize the progression of ripening across multiple tissue types and developmental stages by examining the expression of key ripening-related genes. Fruits were harvested at five developmental stages including ripening. Ethylene was measured from these fruits to identify the stages that coincided with ripening initiation. For each stage, 9 tissue types were collected via dissection to obtain spatial resolution. RNA will be extracted from these tissues for qRT-PCR analyses to determine the expression of a focused-set of ripening related genes. For this study, a total of 37 genes were selected based on a previous RNA-Sequencing study that displayed a differential pattern in their transcript abundance during ripening. A subset of these genes is related to sugar, acid, anthocyanin, phenylpropanoid, photosynthesis, and cell wall metabolism. Further genes related to phytohormone metabolism related to ethylene, ABA, auxin, and jasmonates were included. Also, genes belonging to the NAC and MADS-box family of transcription factors were included. Based on the gene expression analysis, hormones including ABA, auxin and jasmonates will be quantified from a subset of these samples. This study will provide insights into the spatial context of molecular and hormone regulation. The knowledge from this study may help breeding programs aimed at developing cultivars exhibiting synchronous ripening, and the potential development of growth regulators to control ripening in the field.