Identification and Prevalence of Grapevine Virus Diseases (GVD) in North Carolina - Kimberly Heagy Learning Sustainable Edible Gardening through Hands-on Approach with Muscadine Grapes - Claude Judy Jean Creating a Practical Approach for Wine Grape Grower to Predict Grapevine Water Status by Precision Viticulture Technologies - Runze Yu Effect of Planting Distance on PD Resistant Predominantly Vitis Vinifera Grape ‘502-20’ During the Years of Establishment - Elina Coneva Genetics of Adventitious Root Formation in Dormant Bud Cuttings of Grapevines - Sadikshya Sharma Evaluation of Cordon Training System in Blackberry Production - Jayesh Samtani
Grapevine virus diseases (GVD) are a leading cause of economic concern in the US grape and wine industry, including in North Carolina (NC). Visual vineyard observations in summer and fall of 2017 revealed GVD-like symptoms across European-style winegrowing regions in NC. These observations prompted a state-wide vineyard survey with two aims, (1) identify and assess the prevalence of common grapevine viruses in NC and (2) develop a GVD testing service for growers in NC. A vineyard survey was conducted after harvest (October
As the growing number of individuals moving to Florida has increased to over 1000 residents on average per day. Also, with the current focus on Florida’s water conservation
quality, alternative crops are a 15) and the second in March 2024 (n=19). Within both two-hour workshops, participants were able to go home with a muscadine grape cultivar of their choosing. The first workshop covered pest management, cultivar selection, and culture. Participants harvested and sampled fruit from different cultivars and then made cuttings of different varieties to propagate their own. The second workshop focused on the maintenance of grape vines. From the first workshop’s exit survey, participants reported intending on make changes to their landscape practices, including Right Plant Right Place (87%), Fertilize Appropriately (93%), Water Efficiently (67%), and Mulching (73%). 100% of participants also reported willingness to attempt to grow muscadines in the home landscape. From the second workshop, Right Plant Right Place (61%), Fertilize Appropriately (67%), Water Efficiently (44%), and Mulching (55%). 94% of participants self-reported that they felt better in managing muscadine vines, including installation
With the water regulations getting stricter in California and the climatic conditions getting warmer and drier during grape growing seasons, grape growers are forced to improve irrigation efficiency and eventually conserve water usage. This study was designed to incorporate soil moisture sensors and local above-ground weather stations to estimate grapevine water status with the goal to potentially replace pressure chamber measurement, which is the most popular plant-based method of measuring grapevine water status but labor-intensive and time-consuming. The study was conducted in a Barbera vineyard in Fresno, CA and there were four different regimes used in this study, including 50%, 75%, 100% crop evapotranspiration (ETc) replacement, and an over-irrigated condition (>150% ETc). Three Sony’s soil moisture sensors were installed at 20cm, 37.5 cm, and 75 cm in the soil paired with four time-domain reflectometry (TDR) sensors at 20cm, 37.5cm, 75cm, and 150cm in the soil to continuously monitor additional soil conditions besides soil moisture content. The above-ground weather conditions were collected from a nearby California Irrigation Management Information System (CIMIS) station (
Presently, Vitis vinifera grape production in Alabama and the southeastern U.S. is extremely limited due to Pierce’s disease (PD), caused by the bacterium Xylella fastidiosa (Xf) and vectored by insects from the family Cicadellidae. In 2019, UC Davis grape breeding program has released five PD resistant predominantly V. vinifera cultivars which can help sustain the vinifera grape cultivation in the region. Although these new cultivars are currently available, no V. vinifera grape production and management recommendations exist for Alabama conditions. An experimental vineyard was planted at the Chilton Research Extension Center, AL in 2017 to determine the effect of planting distance on vegetative growth and productivity of PD resistant, predominantly V. vinifera advanced selection ‘502-20’. The experiment utilizes a randomized complete block design consisting of three blocks with three vines per block. Vines were planted at an in-row distances of 1.8m, 2.1m and 2.4m and a between row distance of 3.7m and trained to a Watson system. Vine phenology, vegetative growth, yield, and fruit quality characteristics data were recorded during the period of vine establishment (2019-2023). Our results suggest there was a significant treatment by year interaction effect on pruning weight with the lowest pruning weight of 0.8 kg/vine found for vines at an in-row spacing of 2.1m during 2021. Treatment by year interaction also resulted in the highest yield per vine (28.0 kg/vine) measured for vines planted at 2.4m in 2021. Planting distance of 2.4m resulted in a significant increase of the number of clusters per vine during 2021 and 2022 seasons, while no vine spacing effect was found to account for differences in cluster weight, berry mass, or total soluble solids (TSS). Current results indicate planting distance of 2.4m x 3.7m can increase the yield of ‘502-20’ during the years of vine establishment and contribute to sustainable production of PD resistant predominantly V. vinifera grapes in Alabama conditions. Further research will be conducted to expand current knowledge and assist in the development of management recommendations for the successful production of V. vinifera grapes in the region.
Grapevine propagation depends on the formation of adventitious root formation. Vitis riparia and V. rupestris, two native species of North America, serve as the progenitors for the majority of commercially available rootstocks, especially due to their resistance to Phylloxera and ease of propagation. Despite the presence of at least 20 other native Vitis species in North America, many possessing strong resistances to biotic and abiotic stresses, their utilization has been limited by either poor rooting capabilities or insufficient understanding of their rooting potential. This study aims to achieve two main objectives. Firstly, to assess the rooting capabilities of 208 accessions across 20 different species through a dual approach combining traditional evaluation methods with AI-enhanced image analysis. Secondly, to pinpoint the genomic regions linked to rooting ability via a genome-wide association study, which will aid breeding efforts through marker-assisted selection. Preliminary analyses indicate that rooting capability is not solely species-dependent, as there is considerable variation in performance among accessions within the same species. Ultimately, this research will facilitate the development of new, better-adapted rootstocks, which will be crucial in the face of climate change and the increasing prevalence of biotic stresses.
I am a PhD candidate working on grape breeding and genomics at the University of California Davis. I am working on developing high-throughput phenotypic and genomic tools for salt and drought tolerance in grapes.
Tuesday September 24, 2024 1:10pm - 1:20pm HST
South Pacific 4
Commercial blackberry producers use various types of trellising systems to support the canes and prevent damage from wind and added fruit weight. The objective of this study was to determine the fruit yield and quality with a new training and pruning strategy (cordon system) in a T-trellis system. The 2022-23 growing season was the first year of a two-year study to evaluate the conventional winter pruning and training strategy against a modified “cordon” training system, with the Prime-Ark® Traveler cultivar, at the Hampton Roads AREC in Virginia Beach, VA. The study was set up as a completely randomized design with two treatments and six replicates. Each replicate had 3 plants. The conventional pruning and training strategy involved leaving 4 to 6 main canes along with their laterals per plant. The cordon system had 2 to 4 canes pruned to the height of each trellis wire allowing two laterals per cane to extend horizontally along the wire in both directions. The intent was to distribute the fruit weight along the wires, making harvest easier. New primocanes were trained to the wires in the same manner after spent floricanes are removed. All winter pruning was done between 10 and 20 March, 2023. Fertigation was done as per standard extension recommendations. Harvesting was done two to three times per week beginning 30 May and ending 28 August 2023. Fruit yield was collected by replicate and fruits were categorized as marketable Grade 1, Grade 2 or nonmarketable. The nonmarketable fruits were recorded as having white drupelet disorder, diseases, and insect or “other” damage. Fruit size, firmness, total soluble solids (TSS) and pH data were collected on ten Grade 1 berries per harvest week and data were averaged for the season. Statistical analysis was done with two-sample t-test at alpha =0.05. The conventional training and pruning strategy had an overall higher total, marketable and nonmarketable yield. Fruit size was slightly smaller in the cordon system and no differences in firmness, TSS or pH were observed.
Prospects for Grapes in High Tunnels - Paul Read Growing Grapes on the Texas High Plains: A Review of Grower Concerns and Recent Research - Thayne Montague Improving the Climate Resilience of Wine Grape Vineyards via Trellis Selection and Applied Water Amounts in Warm/Hot Viticultural Regions - Runze Yu Heat Stress Effects on South Mississippi Grown Bunch Grapes - Haley Williams Rethinking Chill Models: The Role of Cold Hardiness, Freezing Temperatures and Daily Fluctuation on Promoting Dormancy Progression and Release - Amaya Atucha
High tunnels have proven to be a suitable alternative for a number of small fruits and vegetables, but potential applications for grapes need to be further explored. We have conducted seven years of research with table grapes in high tunnels and demonstrated that profitable production can be achieved with the concomitant reduction of environmental challenges, including vertebrate pests, hail and extremes of weather. This approach has also resulted in less pesticides required to maintain a quality robust canopy. Furthermore, our research has shown that cold storage retains marketable quality, thus enabling extending the marketing season for the cultivars tested (Thomcord, Everest, Marquis, Mars, Canadice and Somerset). In addition, we have explored the potential of growing Vitis vinifera grapes in a high tunnel in the Midwest with the goals of enabling our commercial wineries to have a local source of grapes that are not adapted to field production in Nebraska but are desired by consumers. Vinifera grapes can thus be produced as a local wine varietal or can be employed to enrich wines made from locally adapted cultivars. Data on survival and productivity of specific cultivars such as Cabernet Sauvignon, Tannat, Petit Verdot, Riesling and other vinifera cultivars will be presented while discussing the productivity of closely related new cultivars.
Within the State of Texas the grape (Vitis vinifera) and wine industry has an economic impact of over $20 billion. Currently there are more than 3,700 ha of vineyards within the state, and greater than 80% of Texas vineyards are within the Texas High Plains American Viticultural Area (AVA). High Plains AVA grape growers are blessed with beneficial soil conditions, low biotic stress factors, and a generally favorable climate. However, geophysical challenges within the AVA include dangerous winter temperature extremes, late spring frosts, high wind speed events, thunderstorms, damaging hail, drought, and herbicide volatility and drift concerns. Despite these challenges, the Texas High Plains AVA has gained a reputation for producing high yields and fruit with exceptional quality. This presentation will focus on recent (past three years) research efforts performed by Texas A&M AgriLife Research and Extension and Texas Tech University personnel: investigating grape grower concerns associated with vine water requirements, avoiding grapevine hail damage, estimating vine cultivar bud dormancy traits, and quantifying herbicide drift and volatilization into vineyards. Presented research results benefit Texas High Plains grape growers and give growers additional insight into production practices and management methods suited for grape production within the unique Texas High Plains AVA environment.
Professor, Texas Tech University / Texas A&M AgriLife Research
Dr. Thayne Montague received his Ph.D. in Horticulture Plant Physiology from Utah State University, and is employed by Texas Tech University Department of Plant and Soil Science and Texas A&M AgriLife Research. Dr. Montague's teaching responsibilities include Plant Propagation, Woody... Read More →
In grape vineyards, trellis systems are used to provide specific canopy microclimate to optimize grapevine production, physiological performance, and berry composition. However, many major wine producing regions are being challenged by the constantly increasing air temperature and decreasing available water allocated for agricultural use. The objective of this study was to understand the impact of trellis system and applied water amount on grapevine productivity and grape quality. This study was conducted to evaluate six trellis systems, including a vertical shoot positioned (VSP), two modified VSP systems (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a cane-pruned VSP-Guyot (GY) and three applied water amounts based on various crop evapotranspiration (ETc), including 25%, 50%, and 100%, in 2020 and 2021. The results showed that SH and HQ systems, once fully established, could have higher efficiency in accumulating total soluble solids (TSS) and total yield. Also, these two systems showed greater flavonol and anthocyanin accumulation in grape berry skins compared to the VSPs, possibly resulted from reduced chemical degradation from the hotter environment Being strongly correlated with canopy architecture, the flavonols and molar percentage of quercetin in berry skins, indicated that the VSP systems were more likely to be prone to overexposure and potential photooxidative stress. The three applied water amounts showed that with less water, grapevines would have lowered yield but increased berry flavonoid accumulation. Overall, this experiment provides information about selecting trellis systems and applied water amounts to optimize vineyard productivity and berry quality in warm/hot viticultural regions.
In the challenging climate of Mississippi, where high heat, rainfall, and humidity pose significant challenges to bunch grape (Vitis spp.) production, identifying resilient cultivars is essential for determining stress adaptation and sustainable agricultural practices. This study assessed the heat tolerance of nine interspecific hybrid bunch grape cultivars/selections (‘Ambulo Blanc’, ‘Black Spanish’, ‘Blanc du Bois’, ‘Lomanto’, ‘MidSouth’, ‘Miss Blanc’, ‘Muench’, OK392, ‘Victoria Red’) grown at the Mississippi Agricultural and Forestry Experiment Station South Mississippi Branch in Poplarville, Mississippi, in 2023. Stomatal density, stomatal conductance, transpiration, vapor pressure deficit, and chlorophyll fluorescence were evaluated both in the field and through leaf disks subjected to a 4-hour heat simulation. ‘Miss Blanc’ and OK392 exhibited the highest stomatal density, while ‘Black Spanish’ had the lowest. Monthly in-field measurements showed no significant differences in physiological measurements. Regarding specific cultivars undergoing the heat simulation, ‘Lomanto’ displayed elevated stomatal conductance and transpiration, contrasting with OK392 with lower values. ‘MidSouth’ showcased high chlorophyll fluorescence, whereas ‘Ambulo Blanc’ consistently displayed lower levels. ‘Miss Blanc’ and OK392 exhibited high vapor pressure deficit, while ‘MidSouth’ showed low values. Further analysis unveiled several correlations: a strong positive correlation between stomatal conductance and transpiration (r=0.9, P
This study addresses fundamental questions in bud dormancy, specifically the impact of temperature on chill accumulation and cold hardiness on dormancy release. We evaluated bud cold hardiness (CH) and time to budbreak responses of grapevines throughout chill accumulation under three treatments: constant (5°C), fluctuating (-3.5 to 6.5 °C daily), and field conditions (Madison, WI, USA), during three dormant seasons. Findings reveal that lower temperatures in chill treatments result in greater cold hardiness gains (CHfield>CHfluctuating>CHconstant). All treatments reduce time to budbreak with increased chill accumulation. However, when time to budbreak was adjusted to remove cold acclimation effects, treatment effectiveness changed. Notably, existing chill models (North Carolina, Utah, and Dynamic) fail to accurately describe adjusted budbreak responses. Our results demonstrate how chill treatment effectiveness changes when adjustments for uneven acclimation are considered. We propose a new model that includes freezing temperatures and enhances chill accumulation under fluctuating conditions.
Evaluation of Pierce's Disease-resistant Grapevine Cultivars in South Carolina - Annie Bruno Diversity and Abundance of Bees Visiting Grape Flowers in Wisconsin Vineyards - Christelle Guedot The Grape Health Index: Validation of a New Methodology for Quantifying Wine Grape Spoilage by Means of FT-MIR Spectroscopy - Sonet Van Zyl Transcriptome Analysis of Muscadine Pedicels Reveals Candidate Genes Modulating the Fruit Abscission Process - Alana Brinley World Grape Rootstocks Pedigree Review - Alireza Rahemi Genome Database for Vaccinium: Genomics Data and Tools to Facilitate Research - Jodi Humann Use of Glycine Betaine and Kelp Extract Mitigates Heat Stress in Red Raspberry (Rubus idaeus) - Givemore Munashe Makonya
Recently, there has been an increased interest in wine grape (Vitis vinifera) production in South Carolina (SC). The warm and humid climate in SC creates a conducive environment for a high risk of disease incidence. Despite the typical climate, SC has droughts periodically. Pierce’s Disease (PD), caused by the xylem-limited bacterium Xylella fastidiosa (Xf), is a major limiting factor to grapevine cultivation throughout the United States and, specifically, in the southeastern U.S. However, PD-resistant grapevine cultivars have been released by UC Davis. Xf-infected grapes can be heavily influenced by water deficit. Preliminary data from a drought-stress experiment in the Summer of 2023 indicated two PD-resistant cultivars perform well under a water deficit. The objective of this study was to evaluate the water dynamics and gas exchange of PD-resistant cultivars during periods of drought. In March 2023, five PD- resistant cultivars and one French-American hybrid were planted in a variety trial at Musser Fruit Research Center in Seneca, SC. The drought-stressed PD-resistant ‘Paseante Noir’ and ‘Errante Noir’ had similar carbon dioxide assimilation to well-watered PD-resistant cultivars. PD-resistant cultivar ‘Ambulo Blanc’ showed the worst leaf water status and lowest carbon dioxide assimilation when stressed. In 2024, physiological measurements, such as sap flow, trunk diameter, gas exchange, and water potential, were taken throughout the growing season. Our results supported previous research that some PD- resistant grapevine cultivars perform well in the field under drought conditions.
Bees play an essential role in plant pollination and the ecosystem services they provide to increase the quantity and quality of many agricultural crops. Many food crops are either dependent on, or benefit from, bee pollination, yet bees have experienced population declines due to a combination of factors including pesticide exposure, susceptibility to pathogens and parasites, habitat loss through land use intensification, and lack of suitable resources. Most studies on pollinator conservation and pollination services focus on pollinator-dependent crops and fail to address the role self- and wind-pollinated plants, such as grapes, play in maintaining or threatening pollinators. In vineyards, bees are often overlooked, as they are not required for the pollination of grape. This study aimed to survey the bees visiting grape flowers of cold climate grapes by recording the abundance and diversity of bees. Observations were conducted at six commercial vineyards in South Central Wisconsin during grape bloom, late May to mid-June in 2022. At each vineyard, vines of mixed cold-climate grape varieties were observed between 10:00 and 17:00 hrs on six separate days. Timed observations (5 min per vine) of bees visiting grape inflorescences were conducted at ten randomly selected grape plants per plot per day. In addition, each day, one 10 min wandering transect was walked along two adjacent rows of grape vines and all bees observed visiting grape inflorescences were recorded. To prevent destructive sampling, bees were identified in the field to species when known or assigned to one of 14 pre-determined morphospecies representing 24 likely genera. Timed plant observations showed a total of 1,059 floral visitations, with an average of 0.31 /- 0.16 bees per minute of sampling. During the wandering transects, a total of 417 floral visitations were observed, with 1.44 /- 0.43 bee visits per minute of sampling. This research underscores the need for reduced pesticide inputs, particularly around bloom time, to protect the diversity and abundance of bees visiting grape inflorescences.
For wineries processing hand harvested grapes, a visual inspection of microbial spoilage is expedient and cost effective. However, due to the increasing adoption of machine harvesters, which frequently rupture berry skins making visual inspection less precise, and the high degree of error of visual inspections between individuals, a quantitative approach to assess spoilage is needed. Fourier Transform Mid-Infrared Spectroscopy (FT-MIR), combined with multivariate analysis, is being investigated as an approach to predict grape health as a sample that can be analyzed in less than one minute. Calibration data was obtained from grape samples of Chardonnay, Riesling, Petite Sirah, and Zinfandel, which were sorted into fractions of 0, 5, 10, 15, and 20% microbially impacted clusters in healthy grape material, and analyzed using the spectrophotometer. The spectral data was analyzed using the Partial Least Squares (PLS) regression. Predicting factors included volatile acidity (VA), gluconic acid, ethanol, lactic acid, glucose-fructose content, Brix, titratable acidity, tartaric acid, malic acid, pH, alpha amino nitrogen, ammonia, and yeast assimilable nitrogen (YAN). A model was selected which optimized for a high coefficient of determination (R2) and a low root mean squared error (RMSE). Additional selection criteria included the extent to which predicting factors have been observed to correlate with microbial spoilage in other studies. The model selected had a R2 of 0.620 and a RMSE of 4.596, making it suitable for identifying grapes marked by spoilage. The output of the model was converted to Grape Health Index (GHI) Scores for better usability by operators at the test stand. The GHI was implemented at the test stands of two large-scale wineries during the 2022 and 2023 seasons. Additional wineries will be added in 2024. The testing of the impact of microbial spoilage on wine aging is currently underway. Wines made in 2018, 2019 and 2020 are evaluated for color degradation and browning, anthocyanins, tannins, pigments, and acetaldehyde. The results will be compared with the original harvest results for comparative analysis concluding the project.
Muscadines (Muscadinia rotundifolia Michx) are native to the southeastern United States and have been cultivated for fresh consumption, juice, wine, and other processed products for over 100 years. Manual harvesting is one of the main challenges for fresh market production due to high labor costs. This study aimed to determine muscadine fruit and pedicel characteristics influencing fruit detachment force and to unravel the genes, hormones, and regulatory networks governing muscadine abscission. We characterized the fruit detachment force of muscadine berries across eighteen genotypes and at four developmental stages. Following this, we performed a transcriptome analysis using the mature pedicel tissue of two genotypes, a genotype with high fruit detachment force at maturity and a genotype with low fruit detachment force at maturity, to identify differentially expressed and uniquely expressed genes contributing to fruit detachment. Our results suggest that the abscission process and abscission zone development likely occur at different rates in a genotype and developmental stage dependent manner. Our findings provide valuable knowledge on the progression of fruit abscission and insights for controlling fruit detachment force. This will aid in the development of machine-harvestable cultivars which will increase the sustainability and efficiency of muscadine production.
Grapes belong to the Vitis genus, which includes about 80 species and is considered as two sub-genera, including Euvitis and Muscadinia. Muscadine grapes are sometimes considered as a separate genus in different classification systems and include three species: Muscadinia rotundifolia, Muscadinia munsoniana, and Muscadinia popenoei. The Euvitis sub-genus includes the most commercially important grape varieties. Euvitis is divided into three groups. 1) The American group consists of about 30 species that are important for rootstock breeding; 2) The Asian group consists of about 50 species, which, up to this point, have been underutilized for grape cultivation; and 3) The Eurasian group consists of a single species, Vitis vinifera L., which includes two sub-species of V. vinifera: V. vinifera subsp. sylvestris, considered to be the wild form of grape; and V. vinifera subsp. vinifera, refers to cultivated forms. Of all species in the genus Vitis, the V. vinifera, is undoubtedly the most important worldwide for commercializing grapes and represents the most cultivated varieties worldwide. Other grape species contributed to breeding programs beyond the traditional efforts of rootstock hybridization from wild species. An aphid-like pest, phylloxera (Daktulosphaira vitifoliae), causes damage by feeding on the structural roots of V. vinifera, eventually leading to vine death. In an effort, American Vitis species that coevolved with phylloxera were eventually used as rootstocks for the widely planted V. vinifera scion cultivars. Later, crosses between these wild species became common, and historical breeding efforts led to the modern grape rootstock breeding programs currently active worldwide. Two-thirds of American species have already been used for rootstock breeding. However, it has been reported that the most commonly available rootstocks are derived from just three American species (Vitis berlandieri, Vitis rupestris, and Vitis riparia). Therefore, the most common grape rootstocks have a narrow genetic base, and efforts to extend the gene pools for breeding programs by using other species are of ongoing importance to the industry and scientific community. There are around 1500 grape rootstocks developed in the world, of which around 50 are commonly used as commercial rootstock and play a fundamental role in resistance to biotic and abiotic stresses and adaptation of grapevine to different environmental conditions, a factor that has opened commercial grape growing to regions that might otherwise be overlooked.
The Genome Database for Vaccinium (GDV, www.vaccinium.org) is a community database resource for Vaccinium researchers and breeders. The database contains genomics data for blueberry, cranberry, bilberry, and lingonberry that are integrated with other types of data such as genetic maps, markers, and QTL/GWAS. The genomics data is accessible via a plethora of search interfaces and tools. GDV has over 40 genomes and allows users to view the genomes in JBrowse, query sequences against the genomes in BLAST and view genome synteny via the Synteny Viewer tool. Highly utilized genomes in JBrowse contain tracks of aligned markers, GWAS, and QTL. Standard GDV analyses on the genomes include synteny analysis and functional annotation of predicted genes with InterPro protein domains and GO terms as well as homology to known proteins. The genes and mRNAs of each genome, along with the functional annotations and orthologs/paralogs, are searchable on GDV. Representative genomes are available in the PathwayCyc tool which displays metabolic pathways and allows for transcriptomics or metabolomics data overlays. GDV also has the genomes and structural pangenomes from the Vaccinium Pangenome Project, a product of VacCAP. Expression datasets that are mapped to genomes are also available to explore using the Expression Heatmap tool. Also available in GDV is the Breeding Information Management System (BIMS) that allows breeders to manage and analyze the phenotypic and genotypic data and provides public access to GRIN phenotype data. This presentation will showcase how to access these genomics data through various tools.
Heat stress poses a significant threat to global food production and security by disrupting plant physiological and biochemical processes. Global simulation models predict a 4 to 5°C increase in atmospheric temperatures by the year 2100, as well as increases in the frequency of extreme heat events. This has necessitated preemptive measures to enhance the resiliency of horticultural crop production. Biostimulants, a class of agricultural products, show great promise in mitigating heat stress effects by enhancing physiological and biochemical stress tolerance. However, limited research exists on the efficacy of commercial biostimulant products in improving heat stress tolerance in horticultural crops. This study evaluated the impacts of three exogenously applied commercial biostimulants representing a range of active ingredients and included FRUIT ARMORTM, Optysil®, and KelpXpressTM [active ingredients glycine betaine, silicone, and kelp (Ascophyllum nodosum)extract, respectively], plus a water control, on physiological, biochemical, and growth parameters in different raspberry genotypes exposed to continuous heat stress (Tmax ≥ 35°C/day) in a glasshouse. Over a 28-day period, the biostimulants and the water control were applied weekly to three raspberry genotypes (‘Meeker’, WSU 2188, and ORUS 4715-2). The results indicated that ‘Meeker’ consistently maintained high chlorophyll fluorescence (Fv/Fm) and photosynthesis under control and biostimulant treatments. In contrast, WSU 2188 and ORUS 4715-2 exhibited increased Fv/Fm and photosynthesis when treated with FRUIT ARMORTM. Additionally, KelpXpressTM application improved Fv/Fm in WSU 2188. ‘Meeker’ and WSU 2188 treated with FRUIT ARMORTM and KelpXpressTM accumulated more anthocyanins and had greater shoot and total biomass compared to ORUS 4715-2. These findings underscore genotype-specific and biostimulant-dependent responses to heat stress mitigation. The superior physiological performance by ‘Meeker’ under both control conditions and biostimulant treatments indicates heat tolerance in the genotype. Furthermore, higher anthocyanins accumulation, improved Fv/Fm, enhanced gas exchange, and greater total biomass of WSU 2188, as well as improved Fv/Fm of ORUS 4715-2, suggests that application of the biostimulants contributed to enhanced repair and maintenance of photosystem II (PSII) structural integrity, improved photosynthetic performance, and increased antioxidative capabilities, which may have contributed to higher total biomass of raspberry treated with FRUIT ARMORTM relative to the untreated control. In summary, the positive impacts on physiological, biochemical, and growth parameters support the potential role of biostimulants in enhancing thermotolerance in raspberries and other horticultural crops exposed to heat stress.
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
Using Biochar As a Soil Amendment in Blueberry Production - Zilfina Rubio Effects of Aged Pine Bark Amendments on Container-Grown Southern Highbush Blueberry Growth and Substrate Properties - Brandan Shur Ground Covers Shape Canopy Microclimate And Fruit Quality Components In A Blueberry Orchard - Josh VanderWeide Enhancing Blueberry Production with Photo-Selective Devices - Amit Godara Modeling Production Curves of Southern Highbush Blueberry for Improved Productivity and Efficient Harvestability - J. Martin Zapien-Macias
Biochar was tested as a possible soil amendment for blueberry production and compared with pine bark, which is commonly used as a soil amendment in blueberry production in the southeastern United States. Three treatments were established in sandy soil: biochar, pine bark (commercial standard), and control (non-amended soil) in which the variety ‘Farthing’ was planted. Soil characteristics were measured two months and 11 months after the incorporation of the amendments. Plant growth, and physiological traits were measured a year after planting. Biochar increased soil pH compared to pine bark and non-amended soil (control). Organic matter (OM) was higher in pine bark amended soil than in biochar. Biochar increased the Ca/Mg ratio 2 months after its incorporation and maintained P availability compared to the control and pine bark treatments. Eleven months after the incorporation of the amendments, the aluminum content was higher in the soil amended with biochar than in the control, whereas the Fe content was higher in the soil amended with pine bark than in the control. Manganese levels were lower in the pine bark-amended soil than in any other treatment. Plant growth and physiological responses were not affected by the incorporation of biochar as a soil amendment. However, plants established on the pine-bark amended soil had lower Soil Plant Analysis Development (SPAD), stomatal conductance, and maximum fluorescence than blueberry plants established on biochar or non-amended soil.
Blueberry cultivation is rapidly expanding due to a dramatic increase in the consumption of the fruit. Soilless substrates have been viewed as a method to increase the production and geographic availability of this fruit. The identification of optimal and alternative substrates for the growth and development of the plants is needed to further guide a new and growing industry. The purpose of this study was to investigate the suitability of aped pine bark substrates amended with coconut coir or wood fiber substrates produced from Pinus taeda for container production of southern highbush blueberry (Vaccinium sp.). Plant linears of ‘Star’ blueberry were grown in 7.3-L pots filled with substrates consisting of coconut coir, aged pine bark, and hammermilled wood fiber. These were each amended at three rates (0%, 20%, 40%, 60%, 80%, and 100%). The plants were harvested at 0 days, 70 days, 140 days, and 365 days to assess their growth and development, measuring plant dry weight at each interval. Additionally, the substrate's physical properties, including particle size and air space, were measured during these four periods to determine the degradation and its influence on substrate quality over time. The findings of this study suggest that coconut coir usage can be reduced by using wood fiber or aged pine bark due to the positive effect on early vegetative blueberry growth.
Fruit quality parameters are typically reported by growers and researchers as an average. However, for small fruits such as blueberries, berry-to-berry variability in texture and flavor also impacts the consumer eating experience. The objective of this project was to capture how the uniformity of fruit quality parameters varies by 1) cultivar, 2) berry maturity, and 3) exogenous phytohormone applications. From 2022-2023, analyses were conducted on individual blueberries from multiple studies carried out in commercial fields in Michigan. First, we compared the uniformity of berry mass, diameter, firmness, and total soluble solids (TSS) in six northern highbush blueberry cultivars: “Duke,’ ‘Bluecrop,’ ‘Draper,’ ‘Calypso,’ ‘Elliott,’ and ‘Aurora.’ The uniformity was highest/lowest for berry mass in 'Bluecrop'/'Calypso', firmness in 'Bluecrop’ /‘Aurora,’ and TSS in 'Bluecrop'/'Elliott'. Second, we evaluated how changes in berry maturity due to delayed harvest affected the uniformity of berry mass, diameter, firmness, TSS, pH, total acidity (TA), TSS/TA, and aroma volatile concentrations in: ‘Duke,’ ‘Draper,’ and ‘Calypso’. Delayed harvest did not alter the uniformity of berry mass or TSS, but increased the uniformity of TA and TSS/TA in all three cultivars. The implications of delayed harvest on the uniformity of consumer liking scores will also be discussed. Finally, we tested whether exogenous application of multiple phytohormones impacted the uniformity of berry mass, diameter, firmness, and TSS in ‘Bluecrop’ and ‘Elliott’. Abscisic acid improved the uniformity of berry mass in 'Elliott,' but not firmness or TSS. Meanwhile, jasmonates had a limited effect on the uniformity of fruit quality parameters in 'Bluecrop'. The relative importance of the "average" and "uniformity" of fruit quality parameters will be discussed. We conclude that “uniformity” is an important component of fruit quality in blueberry.
Blueberries rank among the top ten agricultural commodities in Georgia, contributing 2.45% to the state's GDP, with 27,000 acres across the state and a farm gate value of $449.4 million. Blueberry plants are exposed to elevated temperatures and intense solar radiation during the growing season. This research aimed to reduce adverse environmental effects by modifying the spectral distribution of sunlight. Our team examined the application of photoselective devices Opti-Gro and ChromaGro in blueberry production in Georgia. The research experiment was conducted at two locations (Alma and Rebecca, GA) using a randomized complete block design with four treatments: T1 (Opti-Gro), T2 (ChromaGro), T3 (a commercial grow tube), and T4 (control-unprotected plant), each replicated five times. Photoselective devices positively impacted plant height, yield, total soluble solids, anthocyanins, and titratable acidity. Plants under T1 and T2 also resulted in higher net photosynthesis and stomatal conductance. In summary, the use of photoselective devices presents a promising approach to improve blueberry production in Georgia.
Agronomic crops have their yield potential assessed once per growing season at harvest time. In contrast, horticultural crops such as blueberries (Vaccinium spp.) require prolonged harvest periods, spanning 6 to 8 weeks of recurrent mechanical- or hand-picking. Collected data throughout the harvest period offer a comprehensive source of information to estimate production curves (cumulative harvest). These capture the yield dynamics of each cultivar under specific environmental conditions and treatments. For blueberry growers in Florida, desirable production curves should exhibit: 1) accumulation at the beginning of the harvest season (earliness), and 2) reduced harvest periods (concentration). This pattern is advantageous as it could significantly enhance productivity and profitability while simultaneously cutting down labor costs linked to harvest operations. Thus, pinpointing cultivars displaying these beneficial traits is paramount. In this study, we considered the Weibull distribution to model the production curves for each genotype-in-environment combination. Phenotypic and genomic information were combined for model calibration to predict the corresponding parameters of the distribution besides yield performance in a multi-trait framework. To our knowledge, there are no methods in the current literature that address the identification of cultivars that both ripen early and/or are suited for concentrated harvesting. In this study, we employ a novel analytical approach designed to fill this gap, aiming to systematically identify cultivars aligning with these ideal production characteristics.
First They’re Sweet, Then They’re Sour: The Impact of Cultivar, Berry Maturity, and Phytohormones on Blueberry Quality Uniformity - Michael Gasdick Phytohormone and Plant Growth Regulator Use in Blueberry Production – A Review - Daniel Dick Postharvest Quality of ‘Calypso’ Blueberry After Hand and Machine Harvest - Wei Yang Preliminary Findings from the Evaluation of New Cranberry Cultivars in Massachusetts - Giverson Mupambi
Fruit quality parameters are typically reported by growers and researchers as an average. However, for small fruits such as blueberries, berry-to-berry variability in texture and flavor also impacts the consumer eating experience. The objective of this project was to capture how fruit quality uniformity varies by 1) cultivar, 2) berry maturity, and 3) exogenous phytohormone applications. From 2022-2023, analyses were conducted on individual blueberries from multiple studies carried out in commercial fields in Michigan. First, we compared the uniformity of berry weight, diameter, firmness, and total soluble solids in six northern highbush blueberry cultivars: “Duke,’ ‘Bluecrop,’ ‘Draper,’ ‘Calypso,’ ‘Elliott,’ and ‘Aurora.’ Second, we evaluated how changes in berry maturity due to delayed harvest and sequential harvest dates affected the uniformity of berry weight, diameter, firmness, total soluble solids, pH, total acidity, and aroma volatile concentrations in: ‘Duke,’ ‘Draper,’ ‘Calypso,’ and the uniformity of berry weight, diameter, firmness, and total soluble solids in ‘Bluecrop,’ ‘Elliott,’ and ‘Aurora,’ respectively. The implications of delayed harvest on the uniformity of consumer liking scores will also be discussed. Finally, we tested whether exogenous application of multiple phytohormones impacted the uniformity of berry weight, diameter, firmness, and total soluble solids in ‘Bluecrop,’ ‘Elliott,’ and ‘Aurora’. We conclude that “uniformity” is an important component of fruit quality in blueberry.
Plant growth regulators (PGRs) are natural or synthetically derived plant hormones that play a significant role in shaping plant growth and development. In tree fruit and table grape production, PGRs are commonly employed to address production challenges, including modulating crop load and improving fruit size, coloration, and quality. Meanwhile, their use in berry crops such as blueberry remains limited despite the prevalence of production challenges and the availability of registered PGRs for other fruit crops. This review summarizes the existing literature regarding PGR use in blueberry, as well as the current needs for research on PGRs going forward. First, considering the large increase in U.S. blueberry production over the past decade, we highlight the lack of PGRs registered and utilized in blueberry compared to other fruit crops. Second, we summarize the current literature on the utility of PGRs to mitigate challenges in blueberry production, including cold hardiness and frost protection, dormancy release, fruit size and crop load management, fruit quality improvement, post-harvest shelf-life extension. Finally, this work presents future opportunities for research involving PGRs in blueberry production. As blueberry production continues to increase in the U.S. and globally, the need to mitigate production challenges using PGRs will likely also increase.
The 'Calypso' blueberry has emerged as a popular variety widely planted in the Pacific Northwest. Its reputed storage quality and reasonable firmness suggest its suitability for mechanical harvesting in the fresh market using over-the-row machine harvesters. To explore its postharvest quality after both hand and machine harvest, we conducted a comprehensive study in a commercial, 7-year old 'Calypso' field in Oregon. Additionally, a drop test was employed to simulate machine harvesting for fresh market blueberries. Throughout a 4-week period of cold storage, fruit firmness generally remained stable, with occasional increases noted, while berry size remained consistent, indicating 'Calypso' maintains good storage quality. Examination of fruit internal bruise damage (IBD) by cutting berries along the equator revealed consistent levels of IBD throughout cold storage, elucidating why 'Calypso' enjoys a good shelf life. The drop test demonstrated 'Calypso's' resilience to damage from drops, with a similar pattern of fruit IBD development observed between drop-tested and machine-harvested fruits. This study highlights the slow rate of IBD development in 'Calypso' fruit as a crucial factor contributing to its success in machine harvesting for fresh market operations.
Cranberry growers in Massachusetts still rely primarily on heritage cultivars, such as Howes (1843) and ‘Early Black’ (1852). The research aims to increase the profitability and sustainability of the Massachusetts cranberry industry by evaluating twelve new hybrid cultivars for improved yield, fruit quality, disease resistance, and size. The research project was initiated in March 2021 with the prorogation of the new cultivars in a greenhouse. At the same time, the renovation of a 0.75-acre cranberry bog was initiated. The renovation included stripping off the top 0.25 m of the bog and replacing it with new sand. A new irrigation and drainage system was also installed. The new cultivars were planted in June 2021 at the Cranberry Station in East Wareham, Massachusetts. The new cultivars were planted in a randomized, complete block design with four replications per cultivar and buffer zones between the plots. Standard commercial cultural practices for new plantings regarding irrigation, fertilization, pest control, and canopy management were followed. Fruit was removed from the vines to allow maximum resource allocation for canopy growth in 2022, and the first fruit harvest was in 2023. Yield was measured by picking all fruit within a 0.09 m 2 quadrat. The fruit samples were then sieved through an 8-mm opening to remove undersized berries; the remaining berries represented the yield of marketable berries. Additional samples (≈500 g) were collected from each treatment replication for fruit quality analysis. Fruit color was measured using total anthocyanin content (TAcy). Regarding yield, Haines® (353 barrels/acre), Welker™ (287 barrels/acre), and Crimson King (243 barrels/acre) were the most productive, while Vassana® (112 barrels/acre) and HyRed® (117 barrels/acre) performed poorly, with the other cultivars in the mid-range. Scarlet Knight® (81 TAcy), HyRed® (65 TAcy), and Midnight 8 (58 TAcy) had the best fruit color, while Badger (16 TAcy), Granite Red (22 TAcy), Sundance (24 TAcy), and Pilgrim King (26 TAcy) had poor fruit color. The highest fruit rot incidence was observed in HyRed® (37%), Welker™ (52%), and Vassana® (63%), while Granite Red (11%), Mullica Queen® (13%), Badger (18%), and Sundance® (19%) had the lowest incidence. The fruit size measured as fruit diameter was largest in Badger (20.3 mm), Granite Red (20.3 mm), Crimson King (19.8 mm), and Haines® (19.5 mm). In conclusion, first-year harvest data showed differences in the performance of the cultivars under MA growing conditions. Additional data from multiple years are still needed to provide growers with recommendations.
Two Years, Three Genotypes, and Two Locations: Fruit Quality of Native and Cultivated Aroniaberry Grown in Georgia - Leynar Leyton Prohexadione Calcium is an Effective, Dose Dependent Growth Retardant of ‘Osage’ Blackberry - Hannah Lepsch Impacts of the ‘Fan’ Training Method on Blackberry Yield and Fruit Quality on the Rotating Cross-Arm Trellis - Lizzy Herrera Evaluation of a Strawberry (Fragaria × ananassa) Cultivar Trial for Yield and Fruit Quality in Lubbock, Texas - Srijana Panta Active vs. Passive Row Cover Management: Impacts on Abiotic Growing Conditions, Yield, and Pests on Overwintering Strawberry - Wenjing Guan Performance of Containerized Strawberries (Fragaria x ananassa Duch.) in a Greenhouse Environment - Caroline Blanchard Influence of Soil Disinfestation and Beneficial Bacterial Treatments on Anthracnose Fruit Rot Disease and Strawberry Yield - Jayesh Samtani Effect of Temperature and Light during Cold Storage of Strawberry Liners - Lian Duron
Aroniaberry or chokeberry (Aronia sp., Rosaceae) is an attractive new native fruit crop. Native to eastern and central United States, this deciduous tree-like shrub produces berries with one of the highest concentrations of anthocyanins compared to other fruits. Bred for northern climates, A. ‘Viking’ is the most popular fruit cultivar. Fruit production and quality of A. ‘Viking’, Red Chokeberry (A. arbutifolia), and black chokeberry (A. melanocarpa) was evaluated during the 2022 and 2023 growing seasons, in two locations in the state of Georgia: Blairsville (Zone 7a, Blue Ridge region) and Griffin (Zone 8a, Piedmont region). At both locations, 15 two-year old plants of each genotype were planted in 2021. All genotypes increased their yields between growing seasons (2022 to 2023) but the increment was much higher, and plants had higher yields in Blairsville. A. ‘Viking’ performed poorly in Griffin in 2022 (38.33 g and 119.4 average berries /plant) compared to plants in Blairsville (184.83 g and 237 average berries /plant); in 2023, Blairsville yields were 705.58 g and 1308 average berries /plant, but yields were almost zero in Griffin. A similar trend was observed in A. melanocarpa, with higher yields in Blairsville in the first year and no berry production in Griffin during the second year. A. melanocarpa was the genotype with the biggest increment in yield from 30.62 g and 21 average berries/plant in 2022 to 1111.41 g and 1594.95 average berries /plant in 2023 (Blairsville). A. arbutifolia had better yields in Blairsville compared to Griffin, but plants produced berries at both locations during both years. In terms of fruit quality, A. ‘Viking’ berries were tougher and with a stronger skin in Griffin, and there were no significant differences in texture from 2022 to 2023 in Blairsville. A. melanocarpa berries had similar texture and skin strength in both years. A. arbutifolia texture was similar in both locations in 2023, but in 2022 Griffin plants produced tougher fruit with stronger skin. Plants in Blairsville produced sweeter fruit compared to Griffin, across all genotypes.
Blackberry primocane growth management in the Southeastern US relies on tipping to manage vegetative growth. Tipping can increase lateral branching, bearing surface, and subsequent yield. However, the practice is labor intensive and expensive (~$600/acre). Furthermore, tipping wounds are sites for cane blight infection (Leptosphaeria coniothyrium) resulting in cane dieback, decline and death. Alternative strategies to tipping could reduce labor and fungicide inputs in a given season. Prohexadione calcium (P-Ca) is commonly used to control terminal shoot growth in other Rosaceous crops. We evaluated the relationship between P-Ca rate on blackberry vegetative and reproductive development. The experiment was conducted on a mature planting of ‘Osage’ floricane-fruiting blackberry at Clemson University’s Musser Fruit Research Center in Seneca, SC. The experiment had a completely randomized design with four replications. Treatments consisted of an untreated control and P-Ca applied at 62.5, 125, 250, and 500 ppm with a 0.125% (v:v) non-ionic surfactant and 0.39% (v:v) water conditioner. P-Ca treatments were applied 6 times at ~21 day intervals to the same plots across two consecutive years, 2019 and 2020. Regression analysis was conducted to determine the relationships between P-Ca and measured parameters. There was a consistent, negative relationship between P-Ca rate and primocane height across two years, which was linear in 2019 and curvilinear in 2020. A negative curvilinear relationship between P-Ca rate and yield was observed in 2020 beginning 8 weeks after P-Ca treatments were initiated until the final harvest. There were no consistent effects of P-Ca on fruit weight. P-Ca reduced total lateral length, number of lateral branches, and final cane length by 60 - 65% at the 250 ppm and 500 ppm rates. P-Ca is an effective growth retardant of blackberry, but the negative relationship between P-Ca rate and yield merits additional research. Future research should focus on post-harvest applications of P-Ca to minimize dormant pruning costs and applications in controlled environments.
Based on six years of research at the University of Arkansas, the rotating cross-arm (RCA) trellis has been shown to improve several aspects of blackberry production such as yield and fruit quality. Through this research, a new training method coined the ‘fan’ method was developed with the potential to maximize canopy fill and decrease labor. A trial was conducted from 2022 to 2024 at the University of Arkansas Fruit Research Station (UAFRS) in Clarksville, AR to verify the ‘fan’ method and test new cultivars not used in previous trials. The blackberry cultivars ‘Ponca’, ‘Von’ and ‘Caddo’ were planted in 2021 on a 33m row of t-trellis and a 33m row of RCA trellis in a randomized complete block arrangement. The plants were spaced 0.76 m apart in four plant plots replicated three times per trellis treatment. The ‘fan’ training method (primocanes tipped at 30 cm and laterals trained upward and fanned out on the long arm) was implemented on the RCA trellis treatment for all plants. The t-trellis was tipped at the top wire following practices standard for the region. Blackberry yield, fruit quality, and physiological data were collected during 2023 and 2024. Preliminary results from 2023 showed the ‘fan’ method on the RCA can achieve similar yields to the T-trellis but offer the opportunity to protect the crop from severe cold events and reduce the incidence of fruit quality disorders for some cultivars. All the varieties evaluated were found to be suitable for use on the RCA with the fan method however differences in cane vigor were noted and cultivar can be the biggest determinant of yield and fruit quality regardless of trellis type.
Due to its sweet and aromatic flavor, nutritional value, and health-associated beneficial compounds, strawberry (Fragaria x ananassa) is worldwide cultivated fruit crop. Texas strawberry cultivation is gaining popularity because strawberry production may give considerable economic returns in a relative short period of time. However, profitable strawberry cultivation is intricately tied to selection of suitable cultivars for prevailing environmental conditions. To identify the most appropriate cultivars for a specific region, it is critical to thoroughly evaluate strawberry cultivar growth, yield potential, and various quality characteristics within each diverse agro-climatic location. Hence, to evaluate strawberry cultivars for superior yield and fruit quality characteristics and determine suitable cultivars for cultivation in the region, this study was conducted at the TAMU AgriLife Research and Extension Center in Lubbock, TX. Twenty cultivars (8 day neutral and 12 June bearing) were established Fall of 2022 as bare root plants and data collection began Spring of 2023. Each cultivar was assessed for morphological, physiological, and agronomic traits. Trial results reveal significant variation in performance of evaluated cultivars. Yield and berry number were greatest for ‘Rikas’, ‘Cabrillo’, ‘Brilliance’, ‘Fronteras’, and ‘Beauty’, whereas ‘Keepsake’ was the lowest yielding cultivar and produced the fewest number of fruits. Berry size was greatest for ‘Monterey’, ‘Sweet Ann’, ‘Royal Royce’, ‘Cabrillo’, ‘Valiant’ and ‘San Andreas’, whereas ‘Keepsake’ had the smallest berries. Leaf gas exchange measurements revealed photosynthetic rate and conductance was least for ‘Sierra’. Fruit quality (total soluble solids, °Brix) was greatest for ‘Keepsake’ (11.9°) and lowest for ‘Radiance’ (7.6°). ‘Keepsake’ and ‘Victor’ fruit appeared to be resistant to Botrytis, whereas ‘Festival’ and ‘San Andreas’ were more susceptible. ‘Victor’ plants had the greatest percentage canopy green cover, whereas ‘Medallion’ had the least green canopy cover. Yield and fruit quality data indicate top day-neutral cultivar were ‘Cabrillo’, ‘Rikas’, and ‘Beauty’, while top June-bearing cultivars were ‘Brilliance’ and ‘Fronteras’. Preliminary research suggests cultivars ‘Rikas’, ‘Cabrillo’, ‘Brilliance’, ‘Fronteras’, and ‘Beauty’ may be adapted to the Lubbock area and do well for commercial strawberry cultivation. However, results are based upon data from a single growing season, and further research and analysis of data will confirm results.
Locally produced strawberries have outstanding market potential. Yet their production in the north-central US has declined, partly due to risks associated with the traditional matted-row system. While the plasticulture system offers promise, challenges like plug plant availability in late summer persist. Farmers may choose to use bare-root plants and plant in the summer. However, the high labor demand for planting bare-root plants on plastic and the intensive plant care in the summer have limited the use of plasticulture systems to small-scale operations. High tunnels are widely adapted for strawberry production worldwide. This structure protects plants from strong winds and rainfall, providing additional heat units and moderate frost protection. Successful implementation in Indiana, particularly with fall-planted strawberries, has demonstrated significant yield potential. In our initial exploration, an active row cover management strategy, i.e., covering and uncovering the plants daily in the winter months according to temperatures, was employed during winter months. Although the management approach optimized the winter environment for plant growth, it added labor in crop management, and it may not be feasible for farmers who are not on-site during winter months. This study compares four winter cover management strategies in the 2021-2022 and 2022-2023 seasons: No cover (row covers were not used in the entire winter), Active with hoops (row covers were actively managed daily and placed on hoops), Passive with hoops (the beds were covered during the coldest period, row covers were not removed during the day and were placed on hoops), and Passive without hoops (the beds were covered during the coldest period, row covers were not removed during the day and were placed directly on plants). The study found that No cover resulted in lower minimum temperatures and higher average daily PAR. The active management treatment exhibited the highest relative humidity. Marketable strawberry yields were not significantly different among the covering treatments. However, aphid density was notably higher under covers compared to the no-cover treatment. Our findings indicate that active row cover management during winter was not necessary in the strawberry production system, as it did not significantly increase yield compared to passive management strategy or absence of row covers. Furthermore, the passive management strategy, while potentially advantageous in terms of temperature regulation, was not recommended due to the associated risk of elevated aphid populations.
The horticulture industry has seen an increase in the use of greenhouses as an alternative protected systems to grow strawberries (Fragaria ×ananassa Duch.). Growing strawberries in a greenhouse provides the opportunity for earlier and out-of-season harvesting. However, there is limited research on the phenological and physiological performance of strawberries grown in containers under greenhouse conditions. Therefore, this experiment aims to evaluate the phenological and physiological performance of containerized strawberries grown in a greenhouse. In this study, two day-neutral strawberry cultivars, ‘Albion’ and ‘San Andreas’, were planted in 1-gallon nursery pots using 100% pine bark substrate and evaluated for a 5-month growing season. The phenological stages of all flower buds were recorded daily on five selected plants per cultivar. Monthly data was collected on biomass and diurnal photosynthesis. The yield of all plants was recorded, and fruits were separated into marketable and culled categories. During mid-season plants became infected with black root rot (Pythium spp.), and the results reflect the effects of the disease progression. Although the flower phenology was similar between cultivars throughout the production cycle, differences were observed in biomass accumulation and yield. ‘San Andreas’ showed higher growth over time and a decreased proportion of cull fruits during the Pythium infection. The cultivars evaluated showed similar trends in physiological processes, such as assimilation rate, evapotranspiration, intercellular carbon, stomatal conductance, leaf vapor pressure deficit, and quantum efficiency of photosystem II. Although not consistent, ‘San Andreas’ showed significantly higher values for some physiological parameters. These results indicate that strawberry growth and yield differ between cultivars in the greenhouse environment, which could be related to physiological factors that can ultimately translate to differences in disease susceptibility and performance The initial preliminary results of the first experiment indicates that strawberries can be cultivated with satisfactory results in a greenhouse. This alternative method can offer extended growing seasons, allowing for controlling environments, better disease control management, and easier pest control. Moreover, the portability of containers provides flexibility for the producer to arrange plants for space utilization.
Anthracnose fruit rot (AFR) caused by Colletotrichum acutatum is a major strawberry pathogen in the U.S. affecting both perennial and annual systems. This pathogen can survive in the soil rhizosphere from the previous seasons. Anaerobic soil disinfestation (ASD), an alternative to chemical fumigation methods, has been shown to effectively suppress a wide range of soilborne pests. Beneficial bacteria, such as Bacillus spp., are important biocontrol agents due to their capacity to reduce the growth of pathogens while also promoting plant growth. We proposed that ASD, beneficial bacteria, and their combinations could reduce fruit rot diseases of strawberries and improve crop yield and fruit quality parameters. A trial was conducted using a split-plot design with four replicates at the Hampton Roads AREC, Virginia Beach, VA. ‘Chandler’ strawberry plug plants were planted in various treatments as stated below: non-disinfested field plots (Control); field plots treated with Pic-Clor60 at 196 kg/ha (preplant soil fumigant) (Pic); field plots treated with ASD alone. Additionally, strawberry plants in each of these main treatments were treated with one of the following sub-treatments: no beneficial bacteria (untreated control), Bacillus velezensis only; TerraGrow (a mixture of five Bacillus spp.) at 1.7 kg/ha only; and TerraGrow 1.7 kg/ha applied 4 hours post Oxidate 5.0 (27% hydrogen peroxide, 5% acetic acid and 5% peroxyacetic acid) at 23,385 L/ha. Fruits were harvested twice per week starting 5 April through 20 June, 2023. Harvested fruits in each replicate or sub-plot were sorted into marketable and non-marketable categories. Non-marketable fruits included diseased fruits, small fruits or deformed fruits. Fruit weights were summed for the season by replicate and expressed as g/plant. Fruit firmness and total soluble solids (TSS) were measured on five representative marketable fruits per replicate once per harvest week and data were averaged for the season. For AFR, the weight of diseased fruits decreased significantly in sub-plots treated with B. velezensis, TerraGrow, and TerraGrow post Oxidate compared with the untreated control. In general, the ASD treatment significantly decreased the weight of AFR diseased fruits compared to the control and Pic-Clor 60 fumigation treatments. Fruit from ASD treated plots showed increased firmness and higher Total Soluble Solids values compared to Pic-Clor 60 plots. However, the marketable and total yield was lower in the ASD plots compared with other treatments. Our findings indicate that the utilization of beneficial microorganisms with ASD has the potential to reduce fungal diseases in annual hill strawberry production system.
Identifying storage conditions for strawberry liners propagated in controlled environments is needed to enable mass production of plant material for field growers. The objective was to compare the effect of crown diameter (CD), light, and temperature during cold storage (CS) on growth and subsequent yield of ‘Albion’ strawberry liners propagated indoors for 4 weeks under 24 or 16 h·d–1 (experiments 1 and 2, respectively) using white light-emitting diode fixtures. After propagation, plants of two CD (small 10mm) were stored during 4 weeks under 24 temperatures (ranging from -2 to 7 C) and 47% relative humidity, with or without 5 μmol·m–2·s–1 of white light provided for 24 h·d–1. Plants were moved to a common greenhouse compartment after each CS experiment and grown for 8 weeks to evaluate carryover effects on fruit yield. Overall, shoot and root dry mass were lower in plants exposed to CS compared to the initial baseline material, indicating a general loss of biomass during CS, regardless of treatment. The use of light did not affect any of the parameters evaluated, indicating that liners can be stored under darkness. In experiment 1, plants with large CD had higher chlorophyll concentration than those with small CD, but the opposite trend was measured in experiment 2. As expected, plants with large CD had longer petioles and produced more shoots during CS than those with small CD, regardless of experiment. Plants stored under ≤ -1.4 or -1.9 °C for experiments 1 and 2, respectively, died during the carryover phase, suggesting that liners should not be stored at or below these low temperatures. However, no treatment differences were measured after the carryover phase for plants stored in all other treatments. Further results highlighting the effect of temperature during CS will be presented.
Assessing the Viability of Olive Trees as an Alternative Fruit Crop for Cultivation in Florida - Lorenzo Rossi A Comparative Study of Ripening Timelines in Haskap (Lonicera caerulea L.) Cultivars. - Venkateswara Rao Kadium Biostimulants Did Not Influence Strawberry Yield but Increased Fruit Sugar Content - Jayesh Samtani Assessment of Botrytis Fruit Rot Susceptibility in Selected Strawberry Cultivars under Field Conditions - Jayesh Samtani Evaluation of Cordon Training System in Blackberry Production - Jayesh Samtani Effects of Chitosan and Ultraviolet A (UVA) Light on Postharvest of Blackcurrant Fruit - Venkateswara Rao Kadium Updates on the Genome Database for Vaccinium (GDV): How GDV supports Vaccinium Research and Breeding - Roohollah Abdolshahi
Over the past decade, the cultivation of olive trees (Olea europaea) in Florida has experienced remarkable growth, expanding tenfold. Currently, there are more than 60 growers tending to approximately 800 acres spread across 26 counties in Florida. Despite this significant expansion in Florida’s olive tree cultivation, accompanied by a surge in global olive oil demand, research in this area has been lacking. To address this gap, comprehensive data collection commenced in the summer of 2023 through three distinct trials located in Jay, Wauchula, and Fort Pierce, Florida. These trials aim to determine the most productive olive tree varieties and optimal cultivation techniques tailored to Florida’s diverse climate and soil compositions. Given variations in grove management approaches and tree maturity levels, a range of cultivars representing different genotypes were being tested across various locations. The cultivar ‘Arbequina’ was consistent across all trials. In addition to ‘Arbequina’, other cultivars such as ‘Koroneiki’ and ‘Sikitita’ were assessed in Wauchula, while ‘Lecciana’ and ‘Sikitita’ were examined in Fort Pierce. Throughout the trials, parameters including soil fertility, temperature, soil moisture levels, as well as leaf nutrient status and phenological observations were quantified twice a year. No nutrient deficiencies were detected in either soil or leaf samples, but also no consistent patterns regarding flowering or production were observed. The ongoing data collection is expected to shed light on critical aspects regarding the feasibility of olive tree cultivation within the Florida environment and provide valuable insights for growers and stakeholders.
Dr. Rossi’s research program focuses on improving root health and growth on cultivated crops, leading to the development of environmentally sound and effective management methods. He is a horticulturist with specific expertise related to plant stress physiology, root dynamics and... Read More →
Haskap (Lonicera caerulea L.), also known as edible blue honeysuckle or honeyberry, is a new and emerging berry crop in North America. Its resilience to cold temperatures, adaptability to various soil pH levels, distinctive flavor, and health benefits make it suitable for cultivation in colder climates. The period from flowering to fruit ripeness is remarkably brief in haskap, typically ranging from six to eight weeks, offering an advantageous alternative in shorter-growing regions. Yet, detailed guidance on its cultivation and fruit quality is scarce. To aid growers, a two-year study at the Western Agricultural Research Center assessed the ripening timelines of 15 haskap varieties, providing critical data to optimize harvest timing and management practices. Throughout the growing seasons of 2022 and 2023, from May through August, fruit quality and ripening stages were closely monitored two to three times a week by collecting berry samples. From these samples, traits such as total soluble solids content (Brix), pH, total acidity (TA), single berry mass, and berry color changes were measured. Assessment of this phenotypic data revealed distinct patterns for each trait across the different varieties studied. Cultivars such as 'Blue Goose', 'Boreal Beauty', and 'Sugar Mountain Blue' reached their harvest readiness sooner, around approximately 650 growing degree days (GDD) for the year, followed by a reduction in berry size due to water loss and a rise in sugar concentration. In contrast, Aurora, Tana, and Kawai matured more slowly, achieving peak ripeness near ~1000 GDD. Yet, they preserved their mature fruit characteristics (consistent berry weight and sugar levels) through the sampling period’s end. These insights into the ripening patterns of haskap varieties from prominent breeding programs in North America can inform growers as they choose specific cultivars and decide on optimal harvest times.
Botrytis fruit rot (BFR) or grey mold disease, caused by Botrytis cinerea Pers., poses a significant threat to strawberry crop production in the mid-Atlantic region of the U.S. The extensive use of fungicides to combat this fungal disease has resulted in listing the strawberries in the Dirty Dozen fruits and the evolution of fungal strain resistance to fungicides. Hence, exploring potential alternative strategies is crucial to reducing pesticide use and minimizing BFR; as such, utilizing resistant plant cultivars is a potential strategy. With this, the current study aimed to assess the susceptibility of two cultivars to Botrytis, Flavorfest, and Honeoye, which showed resistance to gray mold under in vitro conditions, and compare them with grower standard cultivars, Chandler and Sweet Charlie, under field conditions. The field evaluations were conducted at two locations during the 2022-2023 growing season: Hampton Roads Agriculture Research and Extension Center in Virginia Beach, VA, and a grower farm in Fredericksburg, VA. Transplanting of plants was done on October 12, 2022, in Fredericksburg and October 17, 2022, in Virginia Beach. A randomized complete block design was used in the experiments with four replicates per cultivar in Virginia Beach and three replicates in Fredericksburg, and each replicate had 12 plants. Fruits were harvested twice a week throughout the season to assess BFR occurrence and marketable crop yield. The main effect of the cultivar was significant for Botrytis fruit rot and marketable yield for the season. 'Honeoye' showed the lowest BFR-infested fruits (~6.5 g of fruits/plant), compared to 'Chandler' (22.5 g). However, 'Chandler' showed the highest marketable yield (713 g/plant), followed by 'Sweet Charlie' (473 g), while 'Flavorfest' (261 g) and 'Honeoye' (216 g) produced the lowest yields. Additionally, marketable yield differed by location, with higher yields recorded in Virginia Beach. Post harvest parameters including fruit firmness, total soluble solids (TSS), and pH that were measured on a subsample of fruits in Virginia Beach showed significant cultivar effect . ‘Honeoye’ had the least firm fruit but had the highest TSS for the season, not different than ‘Sweet Charlie’. The fruit pH of ‘Sweet Charlie’ was the highest. Information on resistant cultivars could assist growers in choosing appropriate cultivars to meet their farm production practices.
Blackcurrant (Ribes nigrum L.) is a small fruit known for its health benefits, but treatment effects on postharvest storage for fresh markets remains understudied compared to other berries, such as blueberry (Vaccinium spp.). This work aims to identify the effect of chitosan coating, ultraviolet a (UVA) light, and combined UVA-Chitosan treatments on blackcurrant postharvest storage. Physical (weight loss and firmness) and physiochemical analyses (soluble solid content, pH, citric acid content, and ascorbic acid content) were combined with microbial population quantification, phenolic compound characterization, and antioxidant capacity assessment. Samples were evaluated every three days of storage throughout this experiment. The results indicated that chitosan treatments have positive effects on reducing berry weight loss, maintaining berry firmness, and reducing mold populations. UVA influenced certain bioactive compounds, such as cyanidin-3-galactoside and rutin. The interaction effects from these two treatments were minimal. This study provides important information for blackcurrant postharvest storage and further small fruit storage work, considering both UVA and chitosan had differential beneficial effects on blackcurrant berries’ physical and chemical attributes.
In the past few years, there has been an increased interest in the use of biostimulants for improved crop production. Biostimulants are products that can promote plant growth when applied in amounts so small that they do not provide much nutrition. These are composed of different organisms, compounds or plant extracts; they include beneficial fungi and bacteria, humic and fulvic acid, seaweed extracts, and protein hydrolysates. During the 2022-23 growing season we evaluated three different biostimulant products in annual hill strawberry plasticulture production. ‘Ruby June’ plants were transplanted on 24 Oct, 2022 on non-fumigated beds and were maintained as per grower standard practices. Treatments were as follows (i) no biostimulant (ii) preplant AminoSalmon (247 kg/ha) applied during bed making (3) plugs dipped for 20 seconds in TerraGrow Liquid (TGL, 3ml/38 L) prior to transplanting followed by a foliar spray and a drip application (1.5L/ha) at one, fourteen, and thirty days after transplanting, resuming monthly during spring; and (iv) EZ-GRO 16-0-0 (3.9 kg/ha) drip application 14 days after transplanting and every 14 days during fall, resuming during spring. All non-treatment irrigation valves were closed during treatment injection through the drip lines. Ripe fruit was harvested beginning 31 March and continued twice a week until 16 June. Harvested fruit was categorized into marketable and non-marketable yield by replicate and fruits were weighed for each category. Yields were cumulated for the season and expressed as g/plant for data analysis. For total yield and marketable yield, no treatment differences were found. Fruit size was estimated as g/fruit by weighing 10 marketable fruits weekly. Five marketable fruits were measured weekly for firmness using a texture analyzer then stored at -20 °C for later analysis of pH and total soluble solids (°Brix) using a digital refractometer. While fruit firmness and pH were not influenced by treatments, the application of both the amino salmon and EZ-GRO biostimulants significantly improved total soluble solids values compared to the untreated control.
The Genome Database for Vaccinium (www.vaccinium.org) is a valuable resource for genomics, genetics, and breeding research related to blueberries, cranberries, bilberries, and lingonberries. It provides a wide range of genetic data, including genetic markers, linkage maps, and GWAS/QTL alongside genome data. GDV has the MapViewer tool to dynamically view genetic maps as well as genetic data associated with genomes and powerful search interfaces to query and download genetics data in table formats. For Vaccinium breeders, The Breeding Information Management System (BIMS) is a useful tool for storing, managing, archiving, and analyzing breeding data. Additionally, BIMS can be synchronized with the Field Book App to allow efficient phenotypic data collection and management. This poster will provide an update on new data and tools such as BIMS and MapViewer incorporated in GDV. We will demonstrate how these data and tools can be used for research and breeding activities.
