Impact of Inactivated Yeast Foliar Spray on Chambourcin (Vitis Hybrid) Wine Grapes

Abstract

Chambourcin, a Vitis hybrid red wine grape grown in the eastern and midwestern United States, can have delayed/uneven ripening and low color development. Previous research showed that inactivated yeast applied foliarly to V. vinifera grapevines during ripening increased grape phenolic content and skin thickness. In this current study, Chambourcin grape attributes were evaluated once per week in 2018 and 2019 during ripening and harvest of four grapevine rows sprayed with inactivated yeast and four rows unsprayed (control) in a commercial vineyard. In both years, sprayed vines had berries with higher skin elasticity and lower pH than control vines. Sprayed vines had berries with higher malvidin- and petunidin-3-O-glucoside than control vines in 2018 at each sample date. In 2019, sprayed vines had berries with higher levels of individual and total anthocyanins than control vines at harvest. Inactivated yeast application to grapevines could improve berry attributes, including anthocyanin content, for winemaking.