THE EFFECTS OF BERRY THINNING AND GIBBERELLIN ON RECEL UZUMU TABLE GRAPES

This study was carried out to determine the effects of berry thinning and gibberellin (GA3) on yield and fruit quality of ‘Recel Uzumu’ table grapes. A combined six treatments of gibberellin (control and 40 ppm) and cluster tipping (control, 1/3 and 1/2) were applied at the 3-5 mm berry size stage. Gibberellin was the main factor for the increase in berry size, berry and cluster weight, and yield. Crushing resistance of berries was higher for gibberellin sprayed clusters. Fruit maturity was delayed with gibberellin and it significantly decreased fruit color. Maturity levels of Recel Uzumu berries increased with the amount of berry thinning. Lengths of tipped clusters were shorter than control while there were no differences between 1/3 and ½ berry thinning. Removing parts of clusters did not influence berry and cluster sizes. The total sensory evaluation scores were the highest for thinned grapes that had not been treated with gibberellin.