Generally, the time for spraying pesticides on citrus seedlings in summer should be 7: 00 am 7:00- 10/0, and the best time is about 5: 00 pm. At about 9: 00 a.m., the dew has disappeared, and the sunshine will not be too high, which is the best time for pests to travel for food. Generally, it takes about 15 to 30 days to kill individual pests once.

Citrus is prone to collapse at seedling stage, especially the newly unearthed small citrus seedlings. Let a large number of rootstock seedlings die, resulting in a large number of seedling shortage. The disease is serious, which mainly harms the young neck and rhizome of citrus. At first, there will be some dark brown water stains, which will gradually circle around the stem and the epidermis will rot.

You can sprinkle some black and white ash after the seedlings come out, that is, plant ash and lime are mixed at the ratio of 2: 1. Pay attention to the drainage measures in the community and spray some disinfectants to avoid the spread of this disease. River sand used for covering soil should be cleaned, or it can be covered with burnt soil to reduce the probability of bacteria-like diseases. In the process of planting, we should often inspect the plots. Once the signs of illness are found, the corresponding chemical spray should be used in time to prevent it.

Planting and nursing of young citrus trees

Citrus is usually planted in late February to mid-March before new buds sprout in spring. In areas without frost damage in winter, it can be planted in 10 ~ 1 1 mid-autumn; In April-May of spring and summer, after the growth of spring shoots stops, the survival rate of summer bamboo shoots is also very high. Container seedlings can be planted all year round.

Water shortage affects the growth and development of young citrus trees, and too much soil moisture will cause root rot and even death. Therefore, timely irrigation and drainage is the main measure to solve the problem of seedling water supply.

Because of the strong growth potential of young citrus trees, the main purpose is to shoot and expand the crown, cultivate the backbone branches and increase the crown leaves, so young citrus trees should be lightly cut.

The shaping of young citrus trees is mainly based on the natural growth habits of citrus, and proper methods such as pulling branches and hanging branches are adopted to cultivate the skeleton branches of the crown. The commonly used tree shape is a natural round head shape, and the newly planted tree without bifurcation should be topped and cored. The trunk is 40 ~ 50 cm high, and three main branches should be cultivated. Each main branch should reserve 2 ~ 3 auxiliary main branches, and then configure side branches to form a compact and firm crown skeleton.

Baidu Encyclopedia-Citrus (Rutaceae citrus)