How to fertilize litchi and longan?

How to fertilize litchi and longan? Please give guidance on litchi longan fertilization methods can refer to the following: first, fertility and nutritional characteristics of litchi and longan belong to the disease-free family, are subtropical evergreen fruit trees, their biological and nutritional characteristics have many similarities. The root system has no natural dormancy period all the year round, and the root absorptive capacity is very strong. They all replace the fruiting mother plant by sending out new shoots, and they have to draw new shoots many times in a year, among which summer and autumn shoots are the fruiting mother plants. Litchi and longan are easy to drop flowers and fruits. The flowering time of male and female flowers of litchi is different, the pollination rate is low, the unpollinated female flowers fall off successively at the beginning of young fruit development, at the same time, there is a large amount of honey during litchi flowering, these physiological characteristics make litchi consume a lot of nutrients during flowering period. for litchi trees with weak tree strength, there are often a large number of fallen leaves and withered branches after flowering. In the process of fruit development, the phenomenon of fruit drop may occur in all stages, and the fruit drop is the most serious when the young fruit develops to the size of mung bean. In the seed development stage, the lack of nutrients will cause the death of the embryo and cause the fruit drop in the second stage. In the later stage of fruit development, a large number of tree nutrients transfer and accumulate into the fruit. If there is a lack of nutrients at this time, the fruit will fall for the third time before and after fruit harvest. To ensure the nutrition supply in these stages is an important measure to achieve a bumper harvest. The nutrient contents in leaves and fruits of two litchi varieties Nuomici and Huaichi were determined. The contents of nitrogen, phosphorus and potassium in leaves of Nuomici were 1.547%, 0.442% and 0.431% respectively (N:P2O5:K2O was 1RU 0.09% 0.28), and the nutrients of N, P and K in fruits were 2.494% and 0 respectively. 486% and 2.226% (N:P2O5:K2O is 1 N:P2O5:K2O 0.19% 0.89). The contents of nitrogen, phosphorus and potassium in Huai branch leaves were 1.345%, 0.124% and 0. 5%, respectively. The contents of nitrogen, phosphorus and potassium in the fruit were 2.459%, 0.549% and 2.083%, respectively (N:P2O5:K2O was 1 N:P2O5:K2O 0.09% 0.33), and the nutrients of nitrogen, phosphorus and potassium in the fruit were 2.459%, 0.549% and 2.083%, respectively (N:P2O5:K2O 0.85). The absorption of nitrogen, phosphorus and potassium in the two varieties of litchi was similar, and the absorption of nitrogen was the most, followed by potassium and phosphorus. The determination of nutrient content in shoot branches and leaves of longan at different growth stages was also in the order of nitrogen > potassium > phosphorus. 2. Fertilization technology after litchi and longan enter the fruiting period, in cultivation and management, we should not only strive for a bumper harvest of the current year, but also take into account the high yield of the next year and the following year. 1. Fertilize litchi. Litchi usually sprouts from December to January, blossoms from February to April, fruit develops from May to June, fruit matures from June to July, autumn shoots grow from August to September, and autumn shoots mature from October to November. According to the local experience, the key point of fertilization for litchi fruit trees should be three times. (1) Flower-promoting fertilizer: or pre-flowering fertilizer. It is mainly to enhance the pre-flowering tree nutrition, promote flower bud differentiation, increase the number of female flowers, and reduce the first stage physiological fruit drop during flower drop and young fruit development. The fertilizer should be applied 10-20 days before flowering. It is generally believed that early and middle maturity varieties should be applied before and after "Lesser Cold" in early January, and late maturity varieties should be applied before and after "Greater Cold" in late January. Usually each plant uses 50 kilograms of rotten human feces and 100 kilograms of urine, combined with 1 kilograms of compound fertilizer. (2) strong fruit fertilizer: or strong fruit to protect fruit fertilizer. It is mainly to supplement the nutrient consumption of trees brought by flowering, promote fruit development and reduce the physiological fruit drop in the second stage. This time, fertilizer should be applied from flowering to the second physiological fruit drop, that is, early-maturing species should be applied in early April (Qingming Festival) and late-maturing varieties in late May (Lesser Fullness of Grain). During this period, the 2:1:2 type high concentration compound fertilizer can be selected for the combined application of nitrogen, phosphorus and potassium fertilizer, about 2 kg per plant. Spraying 0.4% borax solution or 50 mg / kg gibberellin mixture in this period has a good effect on flower and fruit protection. (3) shoot-promoting fertilizer: also called fruit-picking fertilizer. It is mainly to promote tree recovery and autumn shoot development, to lay the foundation for high yield in the coming year, but not to make winter shoots germinate. Therefore, fertilization should be timely and appropriate, early-maturing species and strong trees should be applied after fruit harvest, and late-maturing species, trees with more fruit and weak tree strength should be applied 10-15 days before fruit harvest. In this period, organic fertilizer and chemical fertilizer should be applied together, 50 kg of rotten high quality organic fertilizer and 1 kg of 1:1: 1 compound fertilizer should be applied to each plant. two。 Longan fertilization. Compared with litchi, longan has a long production period and late fruit. According to the fertilization experience in the main producing areas of longan in China, longan fruiting trees are generally fertilized 4 times and 5 times in the annual cycle. The main results are as follows: (1) pre-anthesis fertilizer: during flower bud germination of new shoots in February, 0.3-0.6 kg urea and 1 kg calcium superphosphate were applied per plant, mainly to promote flower spike differentiation, increase spike rate and increase the number of female flowers. (2) Flower protection fertilizer: applied at the full flowering stage in April, about 1 kg of high concentration compound fertilizer per plant, mainly to reduce flower drop, increase the fruit setting rate of young fruit and promote summer shoot emergence. (3) Fruit protection fertilizer: after falling flowers in late June, about 1 kg of high concentration compound fertilizer was applied per plant, mainly to promote the development of young fruits and the firmness of summer shoots, and the new summer shoots continued to grow. (4) strong fruit fertilizer: at the end of July and the beginning of August, high concentration compound fertilizer was applied 1kg to 1.5kg per plant, mainly to promote the expansion, fullness and fullness of young fruits, and the new summer shoots continued to be strong. (5) strong tree fertilizer: the application before and after fruit harvest from September to October is mainly to promote the nutrition of the trees after fruit harvest, restore the tree potential, make the autumn shoot develop healthily, and lay the foundation for the fruit in the coming year. In this period, organic fertilizer and chemical fertilizer should be applied together, with 50 kilograms of rotten organic fertilizer and 1.5 kilograms of high concentration compound fertilizer per plant. Click to get more longan planting techniques and more litchi planting techniques.