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.
