First, the cause of lychee physiological fruit During the whole fruit growth and development process, litchi may have fruit shedding at any time, but there is a relatively concentrated shedding period. According to years of research and observation, there are several concentrated physiological fruit drop periods: The first physiological fruit drop period: the fruit drop rate is about 50% 7 to 12 days after the female flower is thanked. Mainly caused by poor pollination and fertilization. The second physiological fruit drop peak period: 25 days after the female flower withering, when the endosperm degenerates and disappears, the disappearance of the endosperm affects the normal development of the embryo, and the endogenous hormone balance imbalance causes the fruit to fall off. The third physiological fruit drop peak period: 50 to 55 days after the female flower withering, the pulp is from the seed base, and about 1/3 of the seed is the rapid growth and development stage of the pulp, which requires a lot of nutrients. In addition, the summer shoots begin to germinate, the roots grow vigorously, causing vegetative growth and reproductive growth disorders leading to fruit drop. The coke nucleus varieties, such as glutinous rice bran, have a peak of fruit drop about 40 days after the female flower has withered, mainly due to embryo abortion. Pre-harvest fruit drop: usually 10 to 15 days before harvest, the fruit is fully developed, sharply increasing, gaining weight, and requiring a large amount of nutrients. Some varieties may cause fruit drop under insufficient nutrient supply or adverse environmental conditions. In addition, the sugar content of the fruit increased during this period. If it rains or rains for a long time, it will cause a lot of cracking fruit: The damage of pests and diseases during flowering and fruit development is also one of the important causes of fruit drop and fruit cracking, especially the pests such as Phytophthora capsici, anthracnose, lychee, and litchi. Second, the main technical measures for strong flowers and fruit preservation According to the conditions required for the normal development of litchi fruits and the period and cause of the peak of fruit drop, in the fruit-preserving technology, effective measures should be taken to solve the adverse conditions and factors that may occur during fruit development, so as to improve the fruit setting rate. Achieve high yields. 1. Cultivate robust flower spikes Strengthen the cultivation and management of litchi, cultivate the maternal branches of timely and robust autumn shoots, lay the foundation for flowering and fruiting, and cultivate a short, strong, well-developed, high proportion of female flowers through a series of techniques for controlling flower growth. This is the premise of litchi fruit. Therefore, on the basis of implementing and strengthening the conventional cultivation management measures, we should do a good job in the cultivation of the mother branches and the control of the flowers. The use of "complex nucleotides", "Litchi fruit-protection" and other strong flowers in the flower growth period creates favorable conditions for fruit preservation. 2. Regulate flowering and flowering The litchi flower has a large amount of flowers, a small proportion of female flowers, and a relatively concentrated flowering period. However, due to different varieties, different growth and development conditions and conditions, the flowering period and flower quantity are very different. Therefore, the growth and development state of the tree is regulated by cultivation techniques. Flowering, controlling the amount of flowers, and increasing the proportion of female flowers can not only reduce nutrient consumption, but also promote the development of female flowers and small fruits, and reduce the impact of bad weather on pollination and fertilization, which is conducive to improving fruit setting rate and regulating flowering and flowering. The main measures are as follows: (1) Regulating the breeding period of the secondary shoots (resulting mother branches). As a result, the mother branches were prematurely excreted. Except for the easy germination of winter shoots, the flowering spikes were large, the amount of flowers was large, the flowering period was early, and the proportion of female flowers was low. If the autumn shoots of the gourd are too late, it will affect the flower bud differentiation and cannot form flowers. Therefore, it is important to cultivate the timely and robust autumn shoots. In general, the results of the tree should be cultivated in the second autumn shoots. The young fruit trees should be cultivated three times in the early autumn. The early shoots of the early maturing varieties should be in the late August and early September, the mid-maturing varieties in the middle and late September, and the late-maturing varieties in the end of September. It is ideal to take out in early October. (2) Artificial spikes or short spikes are one of the main measures to regulate flowering and flowering. For early and middle-maturing long-flowered spikes, the spikes can grow in the spikes; when the centimeters or less, the spikes are removed from the base, and the spikes are re-growed, which can be picked 1 or 2 times. The short-cut varieties are mainly short-cut, and the top 1/2 can be cut off when the spikes grow to 5 to 10 cm. Or cut off the top at 8 to 10 cm when the flower spike grows above 10 cm. (3) Chemical drug control of spikes can cause the leaflets of the leaves to fall off, or killing some of the spikes can reduce the amount of flowers, increase the proportion of female flowers and delay the flowering period appropriately. The treatment method is to spray the flower spikes once with the "Litchi special flower-promoting agent" (40 kg per packet), or spray the flower spikes with "small leaf off" (20 kg per bottle of water) when the flower spikes are 3 to 4 cm. once. For long-flowered varieties (such as scorpion laughter, Shuidong, etc.), when the flower spikes are 5 to 8 cm long, the shoots are dry (20-30 kg per packet), killing the top of the spikes, let It grows again and achieves the effect of artificial picking. 3. Create conditions for normal pollination and fertilization The majority of female flowers must pass the pollination and fertilization process to make their ovary normal development. Although the female and male flowers of litchi are born on the same flower spike, most of the female and male flowers of the variety are not open at the same time, but are commonly known as female and male flowers. Although the mixed orchards of different varieties can be opened at the same time, pollen is pollinated by bees, insects or winds, but often it is affected by rainy weather and pollination and fertilization, resulting in unrealistic flowers. 4. Ring cutting ring ring peeling fruit Ring cutting is a more effective fruit-preserving measure, which is suitable for the growth of the fruit tree, especially the young fruit tree, the effect is more significant. However, loop cutting is not suitable for trees that are old and weak. The circumcision time can be carried out within 10 days after the female flower is thanked. The young glutinous rice bran grows vigorously and can be cut a second time in late May. The ring cut should be carried out on the main branch and the big branch. Choose a large branch with a diameter of about 6 cm. Cut it in a smooth part with an electric knife or a ring cutter ring. The depth of the ring cut can only reach the essence, and the ring cut will be too deep. Causes the branches to die. For the vigorous growth of the young fruit tree, it can also be used on the trunk or the main branch with a stripping width of 0,0,3 cm, and a ring-shaped stripping knife for the spiral ring stripping of the leafy 1 - 1.5 circles, and the ring stripping should be in the flower head 7 It is carried out at 10 cm, such as glutinous rice bran, cassia and other late-maturing varieties. It is carried out 10 days after the stripping or female flowering in the middle of March every year. In addition, in the winter, the main line or main branch is circumscribed by the 16th to 14th iron wire, which has a good effect on the preserved fruit. 5. Apply growth regulator to protect fruit According to the period and cause of physiological fruit drop, the growth regulator is used to preserve the fruit. Generally, the first time is sprayed about 15 days after the female flower is thanked, and the second time is sprayed at intervals of about 8 days, and a total of 2 or 3 times is sprayed, which can effectively Reduce the fruit drop. Litchi can only create a strong flowering and fruit-preserving work to ensure the yield of the results, prevent litchi and cracking fruit, and ensure the quality of litchi, in order to create higher planting benefits. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone Wound Repair,wound healing,scar repair Wound Repair,Adhesions Wound Repair,Wound Care Bandages,Wound Healing Bandages Zhejiang Lanhine Medical Products Ltd. , https://www.lanhinemask.com