Fruit drop, fruit cracking and prevention of longan

The reason for fruit drop: lack of nutrition. The tree is too weak, or consumes too much nutrients, and the fruit falls off because of hunger; rainy weather is easy to cause root hypoxia, diseases and insect pests occur, and so on. Reasons for fruit cracking: there are more fruit cracking in the shaded orchard; the moisture changes too much; the tree age is old and the shoot is weak; the trace elements calcium, magnesium, boron and zinc are deficient and easy to crack fruit; too much nitrogen and potassium fertilizer is also used to crack the fruit. Prevention: before the rapid expansion period of the pulp, during the fruit coloring period and before fruit picking, Yuhualing No. 2 and Yuhualing No. 1 were sprayed with 30 ml of water and 15 kg of water respectively for 3 consecutive times. Spraying Yuhualing can timely supplement various nutritional elements necessary for fruit growth and development, enhance disease resistance, reduce fruit drop, and promote fruit expansion and early ripening. At the same time, it can promote pericarp development, make pericarp tough and permeable, so as to reduce fruit cracking in the later stage of fruit development.