A seedbed or seedling bed is the local soil environment in which seeds are planted. Often it comprises not only the soil but also a specially prepared cold frame, hotbed or raised bed used to grow the seedlings in a controlled environment into larger young plants before transplanting them into a garden or field. A seedling bed is used to increase the number of seeds that germinate. Greenhouse Seedling Bed,Stainless Greenhouse Seedling Bed,Greenhouse Seedling Nursery Bed JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , http://www.spgreenhouse.com
Both litchi and longan belong to Sapindaceae, which are subtropical evergreen trees. Their biological characteristics and nutritional characteristics have many similarities. There is no natural dormancy in the root system throughout the year, and the root absorption ability is very strong. They all replaced the results of the mother line by drawing new shoots. Several new shoots were taken in the year. Among them, summer shoots and autumn shoots were the result of the mother plant.
Litchi and longan are easy to drop. The flowering time of female and male flowers of litchi was inconsistent, and the pollination rate was low. Unpollinated female flowers had fallen off at the beginning of young fruit development. At the same time, the litchi was rich in the amount of honey flowing during flowering. These physiological characteristics caused the litchi flowering period to consume large amounts of nutrients, which was weak for tree vigor. Litchi trees often have a large number of deciduous and dead branches after the flowers are cut. During fruit development, fruit drop may occur at each stage. The fruit drop is most serious when young fruit grows to mung bean size. Fruit drop in this period is also called physiological fruit drop. In the period of seed development, the lack of nutrients will cause the death of the embryo and cause the second stage fruit drop. In the later stages of fruit development, nutrients in the tree are transferred to the fruit and accumulated. If nutrients are insufficient, the fruit will fall for the third time before and after the fruit is harvested. To ensure nutrient supply at these stages is an important measure for obtaining a good harvest.
The contents of nutrients in two litchi cultivars, glutinous rice bran and Huaizhi, were determined in their mature leaves and fruits. The nitrogen, phosphorus and potassium nutrients of glutinous rice bran were 1.547%, 0.142% and 0.431%, respectively (N: P2O5: K2O. For 1:0.09:0.28), the N, P, and K nutrients in fruits were 2.494%, 0.448%, and 2.226%, respectively (N:P2O5:K2O was 1:0.19:0.89). The nitrogen, phosphorus and potassium nutrients in the leaves of Huaizhi were 1.345%, 0.124% and 0.48%, respectively (N: P2O5: K2O was 1:0.09: 0.33). The N, P and K nutrients of fruits were 2.459% and 0.549, respectively. % and 2.083% (N:P2O5:K2O: 1:0.22:0.85). The absorption of N, P and K nutrients in the two litchi species was similar, and they were mostly absorbed by nitrogen, followed by potassium and phosphorus. The results of determining the nutrient content of shoots and leaves in different growth stages of longan were also as follows: nitrogen>potassium>phosphorus.
(two) fertilization technology
After the litchi and longan have entered the fruiting period, they must strive for a fruitful harvest in the year and take into account the high yields of the following year and beyond.
1. Litchi fertilization. Litchi usually sprouts from December to January, flowers from February to April, fruit development from May to June, fruit ripening from June to July, autumn shoots from August to September, and autumn shoots from October to November. According to local experience, the litchi fruit tree fertilization should focus on three times of fertilizer.
(1) promote flower fat: or called before the flower fat. It is mainly to enhance the nutrition of the tree before flowering, promote the differentiation of flower buds, increase the number of female flowers, and reduce the first period of physiological fruit drop when the flowers fall and the young fruit development. The fertilizer should be applied 10 to 20 days before flowering. It is generally believed that the early and mid-maturing varieties should be applied before and after the "Xiao Han" in early January, and the late-maturing varieties should be applied before and after the "Da Han" in late January. Usually each plant uses 50 to 100 kg of decomposed human urine and applies 1 to 1.5 kg of compound fertilizer.
(2) Strong Fruit Fertilizer: Or Strong Fruit Fruit Fertilizer. Mainly to supplement the tree nutrient consumption caused by flowering, promote fruit development, and reduce the second phase of physiological fruit drop. The fertilizer should be applied after flowering and before the second physiological fruit drop, ie early maturing in early April (qingming) and late maturing in late May (small full). This period should be combined with nitrogen, phosphorus, and potassium fertilizers, and can use 2:1:2 high-concentration compound fertilizer, about 2 kg per plant. Spraying 0.4% borax solution or spraying 50 mg/kg gibberellin mixture during this period has a good effect on flower protection and fruit protection.
(3) promote slightly fat: also called fruit fertilizer. It is mainly to promote the restoration of trees and the development of autumn shoots, which will lay the foundation for the next year's high yield, but it will not allow the winter shoots to germinate. Therefore, timely and appropriate amount of fertilization, early maturing species, robust trees should be applied after fruit picking, late-maturing species, the results of many trees and debilitating trees should be applied 10 to 15 days before fruit picking. This period should be combined with organic fertilizer and chemical fertilizer application, each plant composting quality organic fertilizer 50 to 100 kg, 1: 1 to 1 type compound fertilizer 1 to 1.5 kg.
2. Longan fertilization. Compared with litchi, longan has a long production period and the result is late. According to the experience of fertilization in the main longan production area in China, the longan tree is usually fertilized 4 to 5 times during the growth cycle.
(1) Pre-harvest fertilizer: When the buds of new shoots were germinated at the time of germination in February, 0.3-0.6 kg of urea per plant and 1 kg of superphosphate were used to promote flower head differentiation, increase flowering rate, and increase the number of female flowers.
(2) Flowering fertilizer: During the flowering period in April, each high-concentration compound fertilizer was about 1 kilogram, which was mainly to reduce the number of falling flowers, increase the rate of young fruit bearing, and promote summer shoots.
(3) Preserving fruit fertilizer: After being dropped in late June, each plant applied about 1 kilogram of high-concentration compound fertilizer, mainly to promote the development of young fruit and sturdiness in the summer shoots, and the new summer shoots continued to be pumped.
(4) Strong Fruit Fertilizer: It was applied at the end of July and early August. Each plant was applied with a high concentration of 1 to 1.5 kg of compound fertilizer, mainly to promote the expansion, fullness, and fullness of young fruit, and the new summer shoots continued to be strong.
(5) Zhuangshu Fertilizer: Before and after fruit harvesting from September to October, it is mainly to promote nutrient replenishment after tree harvesting and restore tree vigor so that the autumn shoots will develop robustly, laying the foundation for the results of the coming year. This period should be combined with the application of organic fertilizers and chemical fertilizers, each of which applies 50 to 100 kg of organic fertilizer, and 1 to 1.5 kg of high-concentration compound fertilizer.
(I) Fertility and Nutritional Characteristics