EFFECT OF GIBBERELLIC ACID AND ETHEPHON APPLICATIONS ON BERRY COLOR AND QUALITY OF “FLAME SEEDLESS” GRAPES

Abstract

This investigation aimed to evaluate the effect of spraying “Flame Seedless” grapes with gibberellic acid (GA3) and ethephon at 250 ppm when berry size was about 10, 12 and 14 mm on berry color and quality. The present results revealed that spraying “Flame Seedless” grapes with GA3 alone significantly increased cluster weight, berry weight and yield/vine, whereas decreased anthocyanin content and SSC/A ratio in comparison with the control. Moreover, adding ethephon at 250 ppm to the vine which sprayed with GA3 when berry size was about 14 mm significantly increased cluster weight, berry weight and yield/ vine than those treated with ethephon when berry size was about 10 or 12 mm or with GA3 alone. Also, this treatment accelerated harvest date through their its effect on increasing SSC/A ratio in berry juice. Furthermore, vines sprayed with ethephon at 250 ppm when berry size was about 14 mm produced superior color and increased anthocyanin content in berry skin than those sprayed with GA3 alone or the control. It could be concluded that spraying “Flame Seedless” grapes with ethephon at 250 ppm when berry size reached about 14 mm was the suitable date for ethephon application as compared to those sprayed when berry size was about 10 or 12 mm or with GA3 alone.