Effects of Gibberellic acid on Seed and Berry Development in ‘White Malaga’ grape at Doi Inthanon Chiang Mai Province

Abstract

The application of gibberellic acid at a concentration of 50 ppm on inflorescences of ‘White malaga’ grape at full bloom (80% cap fall). 3 days, 5 days and 7 days after full bloom were conducted at Doi Inthanon, Chiang mai province, during January 25-31, 1993. The results showed that the application of gibberellic acid at the concentration of 50 ppm at full bloom stage reduced pollen germination. The germination of the pollen with the treated and untreated were 0-2.21% and 45.24-57.75%, respectively. Gibberellic acid at a concentration of 50 ppm at full bloom, 3 days, 5 days and 7 days after full bloom stage resulted in 98 – 100% seedlessness. The size of berries and clusters were not affected by gibberellic acid. Gibberellic acid application at all stage of inflorescences increased soluble solids and decreased acidity which allowed early harvest.