In the cultivation and management of citrus, the flower volume and fruit setting rate of citrus are easily affected by the climatic environment and management measures. Under the conditions of abnormal climate, low endogenous hormone levels, and insufficient nutrient supply during the flowering and fruiting period, some citrus varieties are likely to have low flower volume, high proportion of deformed flowers, delayed spring shoots turning green, and low fruit set rates. . In view of this phenomenon, it is suggested to promote the greening of new shoots, inhibit the formation of abscission, and improve the Adjust the supply of nutrients, so as to achieve the purpose of improving citrus flower quality, flower quantity and fruit setting rate.
The citrus tree has three peaks of flower and fruit drop. The specific circumstances and reasons are as follows:
(1) The falling flower peak in the first full bloom period is mainly due to the lack of tree nutrient supply and abnormal climate during the flowering period, resulting in a large number of incomplete flowers, deformed flowers and poorly pollinated citrus flowers.
(2) The first physiological fruit drop (with the stalk falling off) usually occurs 10-15 days after the flowers are withered, and it is the largest fruit drop. The main reason for the first physiological fruit drop is the uncoordinated supply of nutrients for tree vegetative growth and reproductive growth, and poor fertilization at flowering stage leads to poor development of young fruit, resulting in physiological fruit drop.
(3) The second physiological fruit drop (without the stalk falling off): the second physiological fruit drop is carried out about 30-40 days after flowering (20-30 days for early-maturing varieties). The main reasons for the second physiological fruit drop are poor environmental and climatic conditions, excessive growth of summer shoots, insufficient nutrient supply and endogenous hormone imbalance in the tree, young fruitgibberellic acid and insufficient auxin content lead to fruit drop, which is more obvious in seedless varieties.

　　first physical fall

　second physiological fall

　　Control measures for citrus flower preservation and fruit preservation:

The flower and fruit drop of citrus is affected by many factors. The treatment of flower preservation and fruit preservation must comprehensively consider various aspects, reasonably control the dynamic balance of endogenous hormones in the plant, and use chemical regulation technology to protect the flower and then the fruit, so as to improve the fruit setting rate of citrus.
(1) Before the citrus blooms, supplement the supply of boron, zinc and other trace elements and organic nutrients, and cooperate with "Mengdi + Ziqi + Baohua Baoguo - alginic acid" to spray the whole plant to promote the robustness of flower buds and improve flower quality. Reduce the proportion of deformed flowers.

　　(2) When 2/3 of the citrus flowers are withered, according to the citrus variety, choose "Guo Kai Package" or "Meng Di + Gibberellic Acid" and spray the whole plant with foliar fertilizers such as amino acids or alginic acid, and phosphorus and potassium fertilizers. , and spray again at intervals of 15-20 days to improve the fruit set rate of citrus.

　　Jiangxi Xinruifeng "Guoqi" fruit preservation effect display

　　Precautions
At each growth stage of citrus, attention should be paid to nutritional supplementation, the prevention of pests and diseases, and the prevention of climate disasters. During the flowering period of citrus, reasonable wiping and control of flowers should promote the supply and distribution of nutrients in flowers and fruits, reduce the consumption of tree nutrients, and help citrus fruit set. inflated.
Due to the differences in citrus varieties and climates in different regions, please consult agricultural technicians for specific drug use plans. Please test and verify a small area before specific application, and then gradually expand the use area after success.