Management of walnut seedlings after planting

   must be irrigated once after planting and again in two weeks, which can improve the survival rate of planting. After that, it should be irrigated in time in case of high temperature or drought. In areas with insufficient water sources, immediately after planting and irrigation, cover the tree plate with straw or plastic film to reduce soil water evaporation. In spring and summer, combined with irrigation, appropriate amount of chemical fertilizer can be applied, mainly nitrogen fertilizer in the early stage, phosphorus and potash fertilizer in the later stage, and foliar fertilizer spraying.

   1. Check survival and replanting under normal circumstances, the young trees can sprout 1 month after planting in spring, the aboveground begins to sprout, and the underground roots begin to grow. However, due to various reasons, a small number of plants did not sprout, the stem lost water seriously, and finally died. Some trees planted in autumn do not sprout temporarily when the growing season comes, but their stems are still fresh and hydrated, so they cannot be judged as dead. These trees may sprout after a period of time. Trees that have been judged to be dead should be replanted in time.

   2. For young trees that have been planted and survived, if the height of the tree is more than 1 meter, it should be dried in time according to the requirements of shaping. When determining the fixed dry height, the characteristics of varieties, cultivation methods, soil and environment should be taken into account at the same time. The crown of early fruiting walnut is smaller, and the fixed stem height is 1. 5%. The height of fixed stem is 1. 5%. When there are intercropping crops, the height of fixed stem is 1. 5%. 5 to 2.0 meters. For walnuts planted in mountainous or sloping land, due to the thinner soil layer and poor fertility, the fixed dry height can be 1. 0%. It's 1. 2 meters.

   northern spring slopes, in the sprouting period of plants and plants, there are often a large number of black velvet beetles gnawing on walnut tree buds, affecting the growth of walnut. You can use plastic film self-made or buy 50cm long 60cm long, 4cm 5cm wide long bag on the seedling stem to protect it. After the seedlings germinate and grow, cut the air at the top and bottom of the plastic bag in time, and take off the long bag after spreading the leaves.

   3. Strengthen tree protection

   (1) after sprouting and spreading leaves, young trees are often vulnerable to aphids, red spiders, beetles and leaf moths, so corresponding measures should be taken in time.

   (2) the temperature of young trees in North and Northwest China is relatively low in winter. The phenomenon of "striping" often occurs in young walnut trees 2 or 3 years after cutting, and the more northward the geographical latitude is, the more serious the "striping" is. The main reasons for "striping" are lack of preparation for overwintering, low temperature in winter, freezing of soil moisture, difficulty in absorbing water by walnut roots, but rapid rise in temperature in early spring, dry and windy air, and large water transpiration of branches. it leads to the imbalance of water budget in the aboveground part of the tree, the occurrence of physiological drying early and "striping", and the phenomenon of "striping" mostly occurs from February to March. For the newly-built walnut orchard, in the spring planting area, in order to prevent serious water loss of the stem after planting, various protective measures can be taken. The spray paraffin emulsion on the trunk is the best, and the effect of 107 glue (polyvinyl alcohol) is also good. Or water glue clay antifreeze, stem covered with slender plastic bags, all have a certain effect. If it is planted in autumn, the seedlings should be managed to survive the winter before freezing, and the thickness of the covered soil should be about 20 cm. When the temperature rises to about 15 ℃ in spring, it should be unearthed in time, and attention should be paid to watering and water conservation of seedlings to improve the survival rate of planting.

The fundamental measures of    to prevent "striping" for young walnut trees are as follows: one is to improve the frost resistance and anti-striping ability of the tree itself. In accordance with the principle of promoting front and back control, attention should be paid to strengthening fertilizer and water management, mainly applying nitrogen fertilizer before July and phosphate fertilizer after July, and properly controlling irrigation. Measures such as coring and controlling the opening angle of growing shoots were taken in the middle of August, and sprayed 0. 5% twice in the first and middle of September. 5% potassium dihydrogen phosphate can effectively control the growth of branches, increase the plumpness of branches, and increase the storage nutrition and resistance of trees. At this stage, it is necessary to timely prevent the leafhopper from laying eggs on the branches. Irrigation for one time in November can effectively increase the soil water content and reduce the occurrence of "striping".