Cultivation techniques of longan in autumn

First, restore the tree potential and enhance the ability to resist adversity. After several months of hanging fruit, longan trees consume a lot of nutrients. The four-month management from August to November in autumn is the key period for the high yield of longan in the following year. It is necessary to increase the pre-harvest fertilizer and post-harvest fertilizer of longan in time, so as to promote the expansion of longan fruit, improve the yield and quality of longan, restore the tree potential of longan as soon as possible, enhance the stress resistance of longan, and lay the foundation for the high and stable yield of longan next year. Taking the yield of 100 jin longan fruit per plant as an example, the pre-harvest fertilizer was mainly quick-acting fertilizer 15 days before harvest, 2 kg of imported compound fertilizer was applied after rain or irrigation, and 2 kg of ternary compound fertilizer and 100 kg of human feces and urine were applied per plant after harvest. The method of fertilization is to dig trenches under the vertical line at the edge of the crown, with a depth of 20cm to 30cm, and cover the soil after applying soil. Where possible, it can be combined with orchard irrigation to increase soil moisture, improve the fertilizer absorption effect of longan trees, and accelerate the recovery of longan trees.

Second, the fruiting mother branches were cultivated to lay the foundation for high yield and high yield in the following year. The ideal fruit mother branch of longan is the last mature autumn branch, so after fruit picking, it is necessary to strengthen the water and fertilizer management of the mother tree in time, promote the germination of autumn, and cultivate the autumn shoot into a strong fruit mother branch. The uniformity of autumn shoot germination is controlled by water and fertilizer, which is convenient for orchard management and pest control.

Pruning and pruning. In order to make the longan tree have a good crown and increase the yield per unit area of longan, the shaping and pruning of longan should be carried out twice a year, spring pruning should be combined with flower and fruit thinning, autumn pruning should be combined with tree crown pruning after fruit harvesting, the branches that are too dominant in growth should be retracted (refers to the first-yielding trees), and the weak branches in the crown, stubble, disease and insect branches and cross branches should be trimmed off. Improve the ventilation in the crown, restore the longan tree potential, naturally regulate the balance of endogenous hormones in the tree, and ensure the flowering rate of longan in the following year.

Fourth, pest control. The temperature is suitable in autumn, so we should pay attention to longan wood lice, fruit borer, moth and other pests. In the method of pest control, during the peak hatching period of larvae, or in the early stage of shoot germination, the fruit growers were organized to spray and kill all kinds of pesticides. Combined with the control of other pests, ① 20% scavenging rate 2000 times or 10% 100% can be sprayed with 2000 times liquid; ② 2.5% enemy kills 2000 times liquid spray, sprayed every 15 days until the new shoots are ripe. Ghost sweeping disease should take deep pruning of diseased branches, at the same time, strengthen the management of water and fertilizer and cultivate stout shoots.

Fifth, transform low-yield orchards. When the temperature drops in autumn and the root activity of longan increases, it is necessary to protect the low-yield orchard and out-of-tube orchard, increase the application of organic fertilizer, improve the soil structure, increase soil ventilation, water conservation, fertilizer conservation capacity and enhance soil fertility. In addition to sufficient nitrogen, phosphorus and potassium fertilizer, but also other trace element fertilizers needed for longan growth, trace elements are mainly sprayed outside the root to ensure the growth and development of longan in each period. At the same time, it is necessary to loosen the soil, renew longan hairy roots, improve root activity, rejuvenate longan trees, and cultivate strong fruiting mother branches, so as to lay a good foundation for the fruit of the following year.