How to ensure high yield of longan adult trees

Environmental factors such as warm winter have seriously affected the fruit yield of longan, so that the yield of longan in Putian has been unsatisfactory in recent years.

The first is variety. The practice of agricultural technology department for many years shows that "Songfengben" longan variety is the first choice variety for good harvest, stable yield and big fruit. It is suggested that fruit growers can graft this improved variety boldly.

Next is the trim off. Pruning focuses on "four cuts": first, frequently cut off thin branches, dense branches, random branches, shade branches, pest branches, etc., cultivate umbrella-shaped crown and thick branches. The second is to cut off redundant flower ears. When thinning and folding flower ears before and after Qingming, cut them off at 1 - 2 sections below the "Gourd Festival"; when thinning and folding before and after grain rain, cut them off at the "Gourd Festival"; when thinning and folding in summer, cut them off at 1 - 2 sections above the "Gourd Festival". Third, boldly cut off spring shoots, cut similar to flower ears, so that more use of summer, autumn shoots germination. 4. Cut off the extra young branches. Summer shoots and autumn shoots of the two "whole bud" is very important, each branch only 1 - 2 young shoots. The purpose of this "four cuts" is to organize the tree shape, cultivate strong fruit mother branches, and also prevent the occurrence of diseases and insect pests.

The third is fertilization. To prevent winter shoots, efforts should be made to fertilize. Adult trees are only fertilized three times a year, using the method of "one layer, two levels and three speeds". "One heavy" is especially important for fertilization in early spring, and the amount of fertilizer should be sufficient and heavy. Not only nitrogen fertilizer, but also phosphorus, potassium fertilizer and a small amount of boron fertilizer, but also a large amount of farm manure, straw and cake fertilizer, this time the amount of fertilizer application accounts for 60% of the total annual fertilizer application. "Erping" is the fertilizer for promoting shoots and strengthening fruits in May. This time, the main fertilizer is human manure or urea, and a small amount of imported compound fertilizer and potassium chloride can be added. This way, it appears balanced and uniform. The fertilizer application amount accounts for 30% of the total annual fertilizer application amount. "Three-speed" is pre-harvest fertilizer, which is applied about 15 days before harvest, and the amount of fertilizer applied accounts for 10% of the total annual fertilizer application. In addition, do not fertilize in winter, but also dig large holes at the appropriate time (experience observation will sprout winter shoots), so that not only for the next spring fertilizer preparation conditions; but also can damage the root system, indirectly achieve the purpose of winter shoot prevention and control.

The fourth is the disease. To pest control, can "indirect cure", cultivate healthy tree body is the most important. Once pests and diseases are found, first of all, artificial culling or removal of diseased branches and leaves to isolate the source of infection; secondly, drug control, must eliminate pests and diseases in the bud. In recent years, fruit growers should pay special attention to the three major moths that harm new shoots: the line moth, the litchi tip moth and the sea wheat moth. The key point of prevention is in August to September (among them, the control of the fine moth is also carried out about 12 days after the longan flower withers), and the summer extension autumn shoot and autumn shoot are sprayed once, and the second time is sprayed every 7 to 10 days.