Effect of GA3 and some plant extracts spraying on fruiting of Early Sweet Seedless grapevines

Abstract

This investigation was conducted during the two successive seasons i.e. 2018 and 2019 on Early Sweet Seedless grapevines grown in Eiat vineyard, El-Odesate district, Luxor Governorate, Egypt. Five treatments of GA3 urea plus active dry yeast, roselle, lemongrass spraying and unsprayed one (control) at various stage of cluster and berry development were evaluated. The experimental vines were arranged in a complete randomized design with three replications. GA3, roselle and lemongrass were applied thrice, where urea twice followed active dry yeast once. From the results, it could be concluded that spraying either GA3, roselle or lemongrass at pre-bloom, full bloom and pea stage. In addition, spraying 1.5% urea at pre-bloom and full-bloom followed 0.4% yeast at pea stage gave heavy and less compact clusters and hastens the ripening with fairly good Early Sweet Seedless berries quality. In addition, it could be used urea plus yeast as well as roselle or lemongrass instead of GA3 in grape production to overcome the adverse GA3 effects.