Influence of gibberellic acid and N6-benzyladenine on the development of seed and shot berries in the seedless grape (Vitis vinifera L.) cv. Perlette

Gibberellins have been used to improve quality of grapes in several cases. However, gibberellic acid (GA) alone is not enough to improve the quality in Perlette. A field experiment was conducted on 3-year-old grape cv. Perlette trained on pergolas, to investigate the effect of bunch dipping with GA(3) and N6-benzyladenine ( BA) on reducing the problem of shot berries and improving the productivity of grapevines. Our observations proved that the stage of application of GA(3) and BA is crucial to avoiding seed formation in seedless varieties such as Perlette for table grapes. The results showed that BA at low ( 10 mu L/L) or high concentration ( 30 mu L/L) at 50% of full bloom caused seed development in the seedless grape cv. Perlette, whereas no seed was formed when BA was used later at the fruit set stage. Based on our studies, we found that bunch dipping with 30 mu L/L GA(3) ( at 50% of full bloom) and 10 mu L/L BA ( at pea size) significantly reduced the problem of shot berries, and improved the yield and quality in grape cv. Perlette.