1, once before flowering and once after fruit setting.

2. Flowering period and fruit setting after each treatment.

As a commercial seedless fruit, the seedless rate should be above 95%, and the seedless rate of high-grade seedless grapes should reach 100%.

The method is as follows:

(1) 7- 10 days before the grape blooms, gibberellin with a concentration of 25ppm and B9 with a concentration of 3000ppm are mixed, and the prepared mixed solution is used to soak the grape young ears for 4-6 seconds respectively;

(2) mixing gibberellin with a concentration of 25ppm and cytokinin with a concentration of 500ppm 5-7 days after the grape blooms, and soaking the grape young ears with the prepared mixed solution for 4-6 seconds respectively;

(3) Seven days after the treatment in (2) is finished, the young grape ears are respectively soaked with cytokinin with the concentration of 500ppm for 4-6 seconds; Finally, it can be processed according to the conventional method.