Impact of Methyl Jasmonate, Abscissic Acid and Ethephon on the Consistency of Flame Seedless Grapes Pre-harvest and Post-harvest

Berry color development of Flame Seedless grapes is considered one of the main maturity indices.  Achieved the requested color at harvest is one of the main problems of Flame Seedless because berries fail to reach the requested level of red color. So, an experiment was carried out on Flame Seedless vines in a private vineyard in the governorate of Sharkia, Egypt. Bunches were sprayed with one of the following five treatments, 0 mg/l (as a control treatment),  Methyle Jasmonate at 0.046 %, Ethephon at 0.24 g/l and at 0.14 g/l,  Ethephon at 0.24 g/l + ABA at 0.015% and  Ethephon at 0.24 g/l + Methyle Jasmonate at 0.046 %.
The single treatments were sprayed at veraison stage while the combined treatments were sprayed at veraison stage and then 5 days later. The combined treatment of (Ethephon + Methyle Jasmonate) was the best treatment, compared control treatment in both seasons, it improves berry color and increases the packable yield at the first harvest. The same treatment significantly increased anthocyanin content and total soluble solids percentage as well as TSS/acid ratio compared with control treatment in both seasons, respectively. Therefore, the combination between Ethephon and Methyle Jasmonate surpassed the other tested treatments in improving berry color and improving berry quality at harvest time. Moreover, the combined treatments with either Ethephon + Methyle Jasmonate was more effective in improving berry coloration and quality than Methyle Jasmonate individually.