HU Jinge, BAI Shijian
The goals of this study was to optimize gibberellin acid (GA3) treatment measure on Thompson Seedless, and to improve the quality of grapes and raisins.This study taken Thompson Seedless grape as material, the experiment consisted of five treatments no treatment during bloom +150 mg/L GA3, 10 days post-bloom, 75 mg/L GA3, 75% bloom +150 mg/L GA3, 10 days post-bloom, 75 mg/L GA3, 100% bloom +150 mg/L GA3, 10 days post-bloom, 75 mg/L GA3, 2 days post-bloom +150 mg/L GA3, 10 days post-bloom, 75 mg/L GA3, 4 days post-bloom +150 mg/L GA3, 10 days post-bloom, no spraying (bloom and post-bloom) was the control, berries quality, raisin quality, and yield were assessed.The results showed that cluster weight, berry weight, shape index, berry hardness and vitamin C content increased with GA3 treatment, promotes the color to green.The L* and a* value of raisin were decreased with GA3 treatment, raisins lost brightness and turned green.The yields of grape and raisin were the highest in (75 mg/L GA3, 2 days post-bloom +150 mg/L GA3, 10 days post-bloom) treatment, with 74.10 t/hm2and 17.33 t/hm2, respectively, single raisin weight and raisin shape index were also the highest in (75 mg/L GA3, 2 days post-bloom +150 mg/L GA3, 10 days post-bloom) treatment, 1.20 g and 2.96, respectively, phenolic substances and antioxidant activity were relatively high.The results of principal component analysis directly reflected the quality distribution of berries and raisins in each treatment, (75 mg/L GA3, 2 days post-bloom +150 mg/L GA3, 10 days post-bloom) had the highest comprehensive score by comprehensive evaluation model, and the effect on Thompson Seedless with (75 mg/L GA3, 2 days post-bloom + 150 mg/L GA3, 10 days post-bloom) was the best.
