How to control the age of plums

1. Reasonable pruning, adjusting the tree potential, the big tree should be cut early (before winter) and re-cut. Cut off withered branches, residual branches, slender twigs, scorched twigs, disease and insect branches and overdense and growing branches. If it is more short, it can promote the growth of shoots, and it should be heavily cut off for prosperous long branches and competitive shoots. Cut off the 2, 3, 3, 3 and 4 shoots of the branches or leave only 3 ~ 5 buds. Early thinning of flower buds, thinning too many flower branches, reducing the amount of hanging fruit. Young trees should be pruned late (before and after the beginning of spring), retain flower branches and remove vegetative branches without flowers. Long or pull branches, ease the tree situation, try to retain flowers and fruits, and increase fruit. two。 In order to adjust the fruit yield, the fruit quantity of the big year tree must be controlled, and the fruit should be thinned at the end of spring and the beginning of summer, that is, about 50 days after flowering, the disease, insect, deformed fruit and tip fruit should be removed first, and then the fruit should be determined according to the leaf-fruit ratio of about 18 ∶ 1. The fruit can also be determined by branch: for large fruit, generally a short fruit branch leaves 1 fruit, that is, the length of the fruiting basal branch is about 10 cm, a fruit is left on the medium fruit branch, 2 fruits are left on the strong branch, the spacing is 6 cm ~ 8 cm; for small fruit, 1 ~ 2 fruit is left on a short fruit branch, the spacing is 4 cm ~ 5 cm. Evenly thinning the fruit in the whole tree to reduce the fruit load, promote the growth of branches and leaves, and ensure high yield in a small year. In order to improve the fruit setting rate of plum, young trees can pick or thinning the strong shoots of strong branches, control the growth of branches, adopt artificial pollination in time, spray 2mai 4Mel D and so on. 3. Scientific fertilization big year trees should re-apply strong fruit fertilizer and postharvest fertilizer. In the period of rapid fruit expansion after anthesis (about late May), plants were applied 50 kg of human and animal manure, 0.3 kg ~ 0.4 kg of urea and 0.3 kg ~ 0.4 kg of potassium sulfate to supplement nutrients and promote fruit development, shoot growth and flower bud differentiation. After fruit harvest, 20 kg of rotten organic fertilizer, 0.2 kg ~ 0.3 kg of urea, 0.4 kg ~ 0.6 kg of calcium superphosphate and 0.3 kg ~ 0.4 kg of potassium sulfate were applied to supplement tree consumption, which was beneficial to the restoration of tree potential and flower bud differentiation, and laid the foundation for high yield in the following year. Young trees should apply pre-flowering fertilizer, about 10 days before flowering, urea 0.1 kg ~ 0.2 kg, potassium sulfate 0.1 kg ~ 0.3 kg. In addition, 0.1%-0.2% borax or 0.2%-4% urea can be sprayed at flowering stage to supplement the deficiency of tree storage nutrients, improve tree nutrition, increase fruit setting rate, and increase yield.