This study was carried out during two successive seasons 2001 and 2002 on
Flame Seedless grapevines grown at a private orchard in Wadi El Faregh Giza
governorate, to evaluate yield and fruit quality after the application of five cluster
thinning methods (GA; at 30 PPM + hand thinning a GA; at 30 PPM + thinning by
cutting back about 25% from the apical portions of cluster — GA; at 30 PPM + thinning
by cutting back 33% from the apical portions of cluster — GA; at 30 PPM + thinning by
removing about 20% from clusters number + shaving GA; at 30 PPM + thinning by
removing about 30% from clusters number + shaving, after fruit set. Thinning methods
improved yield. physical properties of clusters and berries (weight. size. compactness
factor firmness and beny adherence force)‘ chemical properties (TSS-acidity —
TSS/acid ratio - total anthocyanin - total sugar and total amino acids). The data
revealed that thinning by combined treatment 0A3 at 30 PPM + cutting back about
25% from the apical portions of cluster recorded the best beneficial effect on cluster
characteristics of Flame Seedless cv.