Molly Felts, Renee Threlfall,* and M. Elena Garcia
*Institute of Food Science and Engineering, 2650 N. Young Ave, Fayetteville, AR 72704 (rthrelf@uark.edu)

Table grape (Vitis sp.) production in the southeastern United States is limited by pests, disease, and environmental challenges, but could be improved by production in high tunnels. The postharvest marketability of three University of Arkansas table grape cultivars (Faith, Gratitude, and Jupiter) were evaluated. The grapes were established in 2014 on a Geneva Double Curtain trellis in a high tunnel vineyard in Fayetteville, AR. The fruit was handharvested in July and August 2017, then randomized. Two clusters per genotype were placed into a 0.9 kg clamshell in triplicate for analysis. Yield parameters at harvest showed Faith, Gratitude, and Jupiter had cluster weights of 234.84, 407.28, and 110.52 g, respectively, and yield/vine of 35.54, 35.18, and 21.93 kg/vine, respectively. Composition (soluble solids, pH, and titratable acidity) and berry firmness were evaluated at harvest, and marketability attributes (berry firmness, weight loss, decay, and berry drop) were evaluated during storage for 0, seven, 14, and 21 days at 2°C. At harvest, the grapes had soluble solids of 10.70 to 17.40%, pH of 2.91 to 3.85, titratable acidity of 0.38 to 0.76%, and firmness of 2.28 to 3.94 N. There were no significant cultivar × storage interactions for composition, firmness, decay, or berry drop, and storage did not affect these attributes. Firmness and berry drop were not affected by cultivar, but composition and decay were cultivar-dependent. Faith had the most decay (3.36%), followed by Gratitude (2.72%), and Jupiter (0.10%). There was a significant cultivar × storage interaction for weight loss, where weight loss increased during storage for each cultivar. After 21 days storage, Faith had the most weight loss (3.78%), followed by Gratitude (3.05%) and Jupiter (2.36%), but was relatively low for all cultivars. Table grape production in Arkansas has risks, but this study showed that high tunnel table grapes had marketable fruit at harvest and during postharvest storage.

Funding Support: The Southern Sustainable Agriculture Research and Education Grant, United States Department of Agriculture