Viticulture Studies 2021, Vol 1, Num, 1     (Pages: 001-010)

Effects of Gibberellic Acid (GA3) and Berry Thinning on Güz Gülü, Özer Beyazı, Süleymanpaşa Beyazı and Tekirdağ Misketi Seedless Table Grape Cultivars

Cengiz Özer 1 ,Onur Ergönül 1

1 Viticulture Research Institute, Tekirdağ, Turkey DOI : 10.52001/vis.2021.1 Viewed : 6343 - Downloaded : 1663 This study was carried out to determine the effects of berry thinning and gibberellin (GA3) on cluster and fruit quality components of Güz Gülü, Özer Beyazı, Süleymanpaşa Beyazı, and Tekirdağ Misketi seedless table grape cultivars. Gibberellic acid (GA3), a total of 40 ppm, was sprayed to thinned and unthinned clusters at the stages of full bloom and 3-5 mm berry size. Berries were thinned with the removal of one-third of the basal part of clusters. GA3 increased the size of Güz Gülü berries when it was either treated solely or together with berry thinning. Maturity indices increased at GA3 sprayed and thinned Güz Gülü clusters compared to the control. Color L and Color b values of Güz Gülü grapes were highest with gibberellin application. While GA3 increases the berry weight in Süleymanpaşa Beyazı grapes, additional berry thinning is necessary to obtain larger berries. However, the attachment between berry and pedicel of gibberellin sprayed to Süleymanpaşa grapes weakened significantly. The berries of gibberellin-treated Tekirdağ Misketi grapes were heaviest. While the width of the berries did not change with the applications, the length of the berries was highest when only GA3 was applied to Tekirdağ Misketi grapes. Keywords : Grape, gibberellin, berry thinning, quality