The Effects of Some Exogenous Applications on Quality in 'Crimson Seedless' Grape

Crimson Seedless' is a red seedless table grape (Vitis vinifera) and although it is widely cultivated in Aegean Region, it does not develop adequate color in warm climate. the present study was carried out to estimate the effect of abscisic acid (S-ABA), ethephon and girdling on color of bunches and metabolic profile on 'Crimson Seedless' grapevine variety. To achieve this goal, experimental treatments were carried out during two successive seasons (2017-2018). Experimental materials were eight-year-old 'Crimson Seedless' grapevines grafted onto 1103P (V. berlandieri x V. rupestris) of similar vigor and grown in a loamy soil structure under drip irrigation system. in this study a randomized block experimental design with three replications was used, with each plot consisting of six grapevines. Exogenous plant growth regulator (PGR) like S-ABA and Ethephon was applied to the plant materials in five different application method. T4 (S-ABA+ Ethephon) application for 'Crimson Seedless' grape among different applications yielded more effective results on maturity index (SS/TA), total soluble solids (degrees Brix), a*, CIRG (Color Index of Red Grapes) and cluster lenght (mm) properties than other applications. Exogenous S-ABA+ Ethephon promoted color development in 'Crimson Seedless' grape berries. For this reason, it has been determined that T4 (S-ABA+ Ethephon) treatment gives the best results for "Crimson Seeddless" grape variety. These results indicate that 'Crimson Seedless' grapevines grown in a warm climate, where color development is poor, would benefit from a spray of 400 mg/L S-ABA, ten days after the veraison and 500 mg/L Ethephon, ten days after the first S-ABA application.