In citrus cultivation and management, citrus flower quantity and fruit setting rate are easily affected by climate environment and management measures. In the case of abnormal climate, low endogenous hormone levels and insufficient nutrient supply during the flower and fruit period, it is easy to cause some citrus varieties to have fewer flowers, a high proportion of deformed flowers, slow turning of spring shoots and low fruit setting. In view of this phenomenon, it is recommended to apply"plant growth regulatorThe combination of "+ nutrition" promotes the turning of new shoots to green, inhibits the formation of separation layers, and improves and transfers the supply of nutrients, so as to achieve the purpose of improving citrus flower quality, flower quantity and fruit setting rate.
　　Citrus trees have three peaks of flower and fruit drop. The specific conditions and reasons are as follows:
(1) The peak of falling flowers in the first full flowering period is mainly due to the lack of nutrient supply of the tree and the abnormal climate during the flowering period, which caused a large number of incomplete flowers, abnormal flowers and poor pollination of citrus flowers.
(2) The first physiological fruit drop (with fruit stalk falling off) usually occurs 10-15 days after flowering, which is the one with a large amount of fruit drop. The main reason for the first physiological fruit drop is that the nutrient supply of the vegetative growth and reproductive growth of the tree is not coordinated, and the poor fertilization at the flowering stage leads to the poor development of the young fruit causing the physiological fruit drop.
(3) The second physiological fruit drop (without fruit stalk shedding): 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 imbalance of endogenous hormones in the tree, young fruitgibberellic acidAnd the lack of auxin content leads to fruit drop, which is more obvious in the seedless varieties.

The First Physiological Fall

Second Physiological Fall

　　citrus flower fruit control measures:
The flower and fruit drop of citrus are affected by many factors, and the treatment of flower and fruit preservation must be considered in many aspects, the dynamic balance of endogenous hormones of the plant should be reasonably regulated, and the chemical control technology should be used to protect the flower and then the fruit, so as to improve the fruit setting rate of citrus.
(1) Before citrus blooms, supplement boron, zinc and other trace elements and organic nutrition supply, and cooperate with "Meng Di + Zi Qi + Bao Hua Bao Guo-Alginic Acid" to spray the whole plant, so as to promote the robust flower buds, improve the flower quality and reduce the proportion of deformed flowers.

(2) When the citrus flowers are 2/3, according to the citrus varieties, the "fruit set meal" or "adorable + gibberellic acid" shall be reasonably selected and sprayed with foliar fertilizer such as amino acid or alginic acid and phosphorus and potassium fertilizer, and the whole plant shall be sprayed again at intervals of 15-20 days to improve the fruit setting rate of citrus.

Jiangxi Xinruifeng "Guo Qi" Fruit Preservation Effect Display

Precautions
At each growth stage of citrus, attention should be paid to nutritional supplementation, pest control and disaster climate prevention, reasonable wiping and flower control during citrus flowering, promoting the supply and distribution of flower and fruit nutrition, reducing the consumption of tree nutrients, which is conducive to citrus fruit swell.
Due to the differences in citrus varieties and climates in different regions, please consult agricultural technicians for specific drug use plans. Please verify the small area test before specific application, and then gradually expand the use area after success.