The Effects of Gibberellic Acid and Cane Girdling of Applications on Crimson Seedless Grape Variety of Cluster and Berry Characteristics

Crimson Seedless grape variety is a late maturity and small berry size. Berry size is one of the most important quality parameters of table grapes. This trial was carried out in the Crimson Seedless (Vitis vinifera L.) grower vineyard in Sarıgöl (dadağlı) locality of Manisa province in the 2022 vegetation period. A randomized complete block design was used with vines as blocks and clusters as the experimental unit's four treatments and four replications. Vine bunches of Crimson Seedless grape variety, ten years old, were sprayed extensively with a GA3 (Gibberellic Acid) solution (20 mg L-1) on the 25th of April 10th of May, and 10th of June/2022, while girdling (G) was applied from removing 3 mm diameter bark all around from 10 cm below the top of the vine trunk at fruit set stage. Control (C) only water was sprayed. This study aimed to reveal gibberellic acid and cane girdling applications on Crimson Seedless cluster and berry characteristics. Harvest (oBrix 19) was done on the 10th of October/2022 and after that, the cluster weight (g), cluster length (cm), cluster width (cm), berry weight (g), berry length (mm), berry diameter (mm), berry length/berry diameter, total soluble solid, total acidity and maturity index were determined in fresh fruit samples randomly taken from each vine. It was found that all applications generally had statistically (P<0.05) significant effects on grape cluster weight, cluster length, cluster width, berry weight, berry length (BL), berry diameter BD), BL/BD, total soluble solid, total acidity, and maturity index in Crimson Seedless variety. As a result of this study, general recommendations are made of GA3+G, and G as the most suitable applications for growing the Crimson Seedless table grape variety. (Added by: Dr. Baboo Ali)