Effect of Dormex, Fructose and Methionine Spraying on Bud Dor-mancy Release of "Superior" Grapevines

Abstract

This study was carried out during the two successive seasons 2015 and 2016 on 13 years old "Superior" grapevines to study the effect of spraying fructose (3, 5%), methionine (3, 5%) and hydrogen cyanamide 5% (Dormex) on bud dormancy release of "Superior" grapevines. Cyanamide is frequently used for grape bud dormancy release. However, those chemicals are potentially harmful to humans. In this study, we used substances that are less toxic to the environment and grape growers, such as fructose and methionine to determine their effects on "Superior" grape bud break. All treatments significantly improved the percentage of bud break, fruiting buds and yield, as well as the advancement of the harvest date and improving the berry quality compared to untreat ones (control). Also, all treatments induce gradually increased bud contents of IAA and GA 3 and a gradual decrease of ABA from treated date towards buds burst compared to untreated ones. Dormex spraying gave the highest values of studied traits compared to other treatments. No significant differences were found among 5% dormex and 3% fructose spraying. Hence, 3% fructose shows potential for use as a commercial bud break and improves superior grapes fruiting.