Effect of GA3 and lemongrass oil spraying on fruiting of ruby seedless grapevines

الملخص EN

This investigation was conducted during the two successive seasons of 2015 and 2016 at the experimental orchard faculty of agriculture, Assiut University, Egypt, to compare the effects of ga3 and lemongrass oil spraying on fruiting of ruby seedless grapevines.

ga3 spraying was applied twice, once at 5 or 7.5 ppm at full bloom and the second, 30 ppm when the berry size about 5-6 mm, whereas, lemongrass oil spraying was applied at 0.5, 1 or 1.5% at the same previous dates.

the results obtained could be summarized under the following main points: lemongrass oil twice spraying significantly decreased the berry set percentage, cluster weight and yield/vine and consequently significantly decreased the cluster compactness coefficient compared to the unsprayed ones.

on other hand, ga3 twice spraying significantly decreased the berry set percentage and insignificantly decreased the cluster weight and yield/vine, as well as significantly decreased the cluster compactness compared to unsprayed ones.

no significant differences in these traits due to lemongrass oil spray at 1 or 1.5% as well as ga3 at 5 or 7.5 ppm.

lemongrass oil significantly improved the berry quality in terms of berry weight, total soluble solids and anthocyanin contents, whereas ga3 significantly increased the berry weight and significantly decreased anthocyanin content.

from this study, it is clear that lemongrass oil twice spray at 1% improve the grapevines production and overcome the adverse effects of ga3 used at high concentration.