Yield and Quality Aspects of ‘Sra Roucha’ Seedless Grapes as Affected by Gibberellic Acid
‘Sra Roucha’ is an early ripening seedless variety grown successfully under Steppe climate of Afghanistan. Its main problems are lower yield and quality, in terms of, cluster compactness, berry size and firmness. This experiment was undertaken for three growing seasons (2015-2017) at Ordokhan research station in Herat province of Afghanistan to investigate the effect of GA3 on yield, cluster and berry characters as well as sensory features. Treatments were: control, 10mg/L GA3 pre-bloom; 20mg/L GA3 pre-bloom; 10mg/L GA3 at 40% bloom; 20mg/L GA3 at 40% bloom; 10mg/L GA3 at 40% bloom + 10mg/L GA3 at 80% bloom; 20mg/L GA3 at 40% bloom + 20mg/L GA3 at 80% bloom; 10mg/L GA3 pre-bloom + 60 mg/L GA3 at 4 mm berry-size stage; 10mg/L GA3 pre-bloom + 60mg/L GA3 at 4 mm berry-size stage). Each treatment was replicated thrice with one vine per replicate. The experiment was run as split-plot in the frame of randomized complete block design. Data pertinent with sensory attributes were analyzed by Friedman’s non-parametric two-way ANOVA. Results showed that GA3 treatments significantly affected yield, cluster length, weight and compactness, berry diameter, berry length and berry TSS, color, taste and firmness. Application of 20 mg/L GA3 before flowering plus 60 mg/L GA3 at 4 mm berry-size stage, resulted in higher yield, cluster and berry characteristics as well as berry sensory features. Therefore, GA3 (20 mg/L pre-bloom + 60 mg/L at 4mm berry-size stage) is the reasonable technique for enhancing yield and quality aspects of ‘Sra Roucha’ seedless grapes.