Recently, Meng Xianhui, a farmer from Jiyang County, Shandong Province, reported that his family's persimmon trees had a particularly serious fruit drop this year. The fruit-drop rate of individual persimmon trees has reached 80%. What is the reason? In view of the universality of this issue, the reasons for fruit drop from persimmon trees are analyzed as follows. There are two causes of fruit drop in persimmon trees: The first is the physiological drop caused by the physiological disorder of the persimmon tree itself; The second is fruit drop caused by pests or diseases such as anthrax or kaki. No matter what type, it may cause serious economic losses. A. Persimmon physiological fruit drop The degree of physiological fruit drop in persimmon trees varies greatly among varieties. The main plant variety, Damopan persimmon, is lighter and generally does not exceed 10%. Da Hong Pao varieties entered the fruit period, the fruit drop serious, the most fruit drop rate of 2/3. The degree of physiological drop is related to the result site. In the same tree, there were fewer fruit drop on the periphery and upper part of the canopy, but there were more fruit drop on the lower part and inner part. This is related to the different degree of light in different parts. Therefore, the result of the branch or the result is that the mother branch is located at the top or grows strong, and the fruit drop is small. On the contrary, if the branch is located at the lower part or the branches are thin, the fruit drop is heavy. On the same result branch, the fruits in the middle were the lightest fruit drop, followed by the top and the heaviest at the base. This is related to the degree of flower bud differentiation in the shoots. The flower buds in the middle were differentiated earlier and the differentiation rate was faster, and the fruit drop was lighter. Physiological fruit drop occurs mostly after flowering until mid-July. The fruit drop before and after wheat harvest is the most serious, accounting for about 80% of the total number of fruit droppings in the whole year. Individual varieties will also have a fruit drop in August-September. In summary, the main reasons for the occurrence of physiological fruit drop: First, incomplete flower bud differentiation, causing early fruit drop; Second, poor pollination, some varieties do not need pollination, such as a large grinding disc, varieties with this characteristic is not easy to physiological fruit drop, and some Varieties, especially most of the sweet persimmon varieties in Japan, must be equipped with pollination trees, otherwise the fruits will not develop and the fruit drop will be severe in the early days. Third, the weather will cause rain and flowering during the flowering period, which will affect the fruit-falling when pollination occurs. Fourth, the tree structure is unreasonable. Poor ventilation and light transmission cause the growth of the trees to be weak and easy to fall off. Fifth, the lack of fertilizer and water, long-term dry soil, poor soil, and difficulty in absorbing fertilizer and water, resulting in more fruit drop; sixth, excessive soil moisture, decreased root absorption capacity, even if applied With more fertilizer, the tree is hard to absorb and use. Sometimes it will fall because of insufficient supply of nutrients. Second, due to pests and diseases caused by fruit drop 1. Severe damage to Shikita. Shizillae is generally damaged before and after the harvest of wheat. The first generation of damaged fruit is not easy to fall off and will be hung on the tree. The larvae will be decomposed and continue the second generation of damage. The fruit of the second generation of victims is changed from yellow-green to orange-red, and it is easy to fall off when hard and soft. 2. Anthrax damage. In the late growth stage, a large number of diseases usually occur in September, causing fruit drop. Third, prevention and control measures Prevent persimmon fruit drop 1 is the configuration of the pollination tree species (for species that must be configured with pollination trees). 2 is the flowering period of the trunk or main branch of the strong tree, the width should not exceed 0.5 cm. For safety reasons, it is best to leave a seat belt or use a spiral ring to facilitate healing. In addition, the fertilizer and water supply should be strengthened after the ring cutting. 3 is appropriate trimming, in particular, to strengthen the summer trim, remove unwanted and redundant shoots, promote air and light. 4 It is to prevent and control pests, strengthen fertilizer and water management, and increase tree vigor. 5 is the natural brassin, which is sprayed 6000 times in the flowering period or young fruit period, --- Shuofeng 481, which is good for preventing fruit drop. 6 is to top-dress fertilizer once a year in autumn and spring. According to the age of trees, 100 kg of no-tillage (sulfur) per mu and 2500 kg of mixed fertilizer are used. Kitchen Products,Customized Bamboo Straw,Bamboo Straw With Logo,Bamboo Straw With Brush Yangzhou Tongfun Red International Trading Co,Ltd. , https://www.i-ecbio.com