1. CCC, also known as ccc, can effectively inhibit the vegetative growth of grapes, improve fruit setting rate, increase yield, improve quality and promote flower bud differentiation. In production, chlormequat is mainly used to inhibit the sprouting of grape auxiliary shoots, instead of manual picking and removing auxiliary shoots. The method of use is to spray 100-200 mg/kg of chlormequat solution on the plant 5-10 days before flowering, which can control the sprouting of secondary shoots, and properly increase the concentration of drug for the plants with vigorous growth and less fruit.

2. PP333 is a new plant growth inhibitor. The application of paclobutrazol in production can better control the growth of grape secondary shoots, shorten the length of internodes, increase the thickness of leaves, improve the fruit setting rate, make the ear grow compact, and increase the yield per unit area, especially in controlling the growth of summer shoots and reducing the workload of summer pruning.

The use method of paclobutrazol is:

① In the cultivation of vitis amurensis, spraying 4000-5000 mg/kg of multi-effect on the leaves at the end of flowering can increase the weight of single ear of fruit and significantly inhibit the growth of new shoots and the emergence of secondary shoots in the current year. The spraying effect on the leaves can maintain for one year, but there is no obvious aftereffect in the next year.

② On Jufeng variety, spraying 300-600 mg/kg paclobutrazol on the leaves after flowering can significantly inhibit the growth of new shoots and summer shoots, improve the fruit setting rate and make the ear grow compactly.

③ Paclobutrazol can be sprayed on both leaves and soil. The dosage for soil application is 0.7-0.9 g of pesticide under 1 square meter of tree canopy. The soil still has certain efficacy in the second year after application. The soil shall be applied to the lateral root and absorption root, and the soil shall be irrigated in time after application.

Several problems that must be paid attention to when applying paclobutrazol:

① Leaf spray should be applied at the early stage of grape new shoot growth (generally at the end of grape flowering), and too late has no obvious inhibitory effect on new shoot growth.

② Paclobutrazol is mainly used for young and middle-aged grape trees with vigorous growth, but not for trees with weak growth potential.

③ Paclobutrazol can significantly inhibit the growth of new shoots, but it also often delays the germination, makes the ear too compact and easy to form small green grains. Especially when the spraying time is too late, it is easy to delay the ripening and reduce the sugar content. Moreover, different varieties and different regions have certain differences in response to paclobutrazol. Therefore, it is necessary to conduct experimental observation before use to determine the appropriate dosage and use method.