2019 ASHS Annual Conference

Commercial field production of table grapes in Nebraska vineyards has been attempted, but although production is feasible, quality issues have prevented wide adoption. Because the grape berries often are damaged by various environmental factors, considerable labor expense to remove damaged berries and thus provide marketable clusters has made field production unprofitable. We therefore established a project to attempt to produce a quality product by growing table grapes under protection in a high tunnel. Five cultivars are being tested to determine suitability for production in a high tunnel constructed on the University of Nebraska Horticulture Garden area in Lincoln, Nebraska. Cultivars included ‘Canadice’, ‘Marquis’, ‘Mars’, ‘Somerset Seedless’ and ‘Thomcord’. Bare root plants were planted in the spring of 2017 in rows oriented north/south employing a bilateral high cordon trellis system, with the planting consisting of three 5-plant replications in a completely randomized block design. Cluster removal was practiced to prevent fruiting with the goal of harvest measurements to be taken in the 2019 growing season; bud burst, fruit set and vine growth data will be presented. Growth measurements were recorded in the first two growing seasons with results indicating significant differences among the cultivars as follows: ‘Thomcord’ > ‘Somerset Seedless’ = ‘Mars’ > ‘Marquis’ > ‘Canadice’. The exceptional vigor of ‘Thomcord’ was surprising, since it had not been tested in our previous research and was considered to be suspect in terms of hardiness, suggesting that further monitoring will be required. Temperatures inside the high tunnel versus the ambient outside environment have been monitored throughout the duration of the project; temperature management and modification is achieved via adjustable side-vents. This project, if successful, will provide Nebraska growers with an alternative to wine grape production, possibly filling an early season high-value niche market.