[management of ash] maintenance and management technology of ash

Ash tree is a tree species with both landscape value and economic value, but only high quality ash trees can produce their corresponding value, so the management of ash trees is also very important.

Management of Fraxinus chinensis seedlings

1. Irrigation and drainage. During the germination of ash seeds, the bed surface should be kept moist and irrigated a few times. After the seedlings are fully developed, the cotyledons are fully developed and enter the vigorous growth period. The irrigation amount should be more and the frequency should be less. The irrigation should be done once every 2~3 days, and the irrigation should be fully irrigated every time. Irrigation time should be carried out in the morning and evening. It needs to be drained in time when it rains in autumn.

2. Cut. Fraxinus chinensis is a pseudodichotomous tree species. To cultivate tall stems, the basic principle is to transform the top shoots into sympodial branches, so that the trunk grows upward and forms tall stems. The shaping method adopts natural open heart shape, trunk sparse layer shape and multi-leading trunk shape. Because it is dry weaker, layer sex also is not apparent, but budding force, sprout tiller sex is strong. Resistant to pruning. Its opposite buds often extend upward at the same time. If the force is uniform, it is easy to form a binary tree shape, which affects the growth of high growth. In order to form a single shoot tree, one strong shoot must be selected as the trunk culture when the shoot grows to 10 cm after germination, and the other weak branch must be removed to inhibit its growth and be used as an auxiliary branch. For the new branches appearing in the lower part, some should be reserved as auxiliary branches, and the new branches near the base or below 1m should be thinned out at the base. The second year winter shear, seedlings up to 2m or so, and relatively strong, then can stay last year's auxiliary branch Qi base thinning, and then cut off the center of the main branch apex about 1/3, cut the opposite bud under the mouth, to strip 1, leave bud direction pay attention to the opposite of the previous year, so that a left and a right to continue to grow, easy to form straight stem.

3. Topdressing. Fraxinus fraxinus fertilizer should be based on the base fertilizer, in order to make seedlings fast-growing strong, growth season should be supplemented with chemical fertilizer. N fertilizer should be applied at seedling stage of ash tree, N fertilizer, K fertilizer or several kinds of fertilizers should be applied at fast growing stage, N fertilizer should be stopped at late growth stage, K fertilizer should be applied more, top fertilizer should be mainly quick-acting fertilizer, small amount should be applied many times.

4. Thinning seedlings. To adjust the density of ash trees, thinning and replanting should be carried out. The nursery of ash seed seedling is generally thinned twice, the first time when the seedlings grow two pairs of true leaves, and the second time when the leaves overlap each other. Thinning seedlings should be kept good and bad, and it is best to thin seedlings when the soil is wet after rain.

Control of Common Diseases and Pests of Fraxinus chinensis

Brown spot disease: The disease affects the leaves of ash trees, causing early defoliation and affecting the growth of ash trees in the current year. The pathogen is attached to the front of leaves, scattered polygonal or nearly circular brown spots, grayish brown in the center of the spots, 1-2mm in diameter, and 5-8mm in large spots. The positive side of the spot is covered with brown mold spots, i.e. the fruiting bodies of the fungus.

Control methods:

1. Sowing seedlings should be thinned in time, and fertilizer and water management should be strengthened in the early stage to enhance the disease resistance of ash trees.

2. In autumn, clean the diseased leaves on the ground of the remaining bed seedlings to reduce the overwintering bacteria source.

3. Spraying 1:2:200 times Bordeaux mixture or 65% Zineb WP 600 times 2-3 times in June and July has good disease prevention effect.

Prevention and control of tip beetle:

1. During the adult occurrence period, mobilize the masses to kill them sooner or later.

2. Cut off the spawning branches and harmful larvae.

3. Before the larvae mature into the soil, feed chickens and ducks in the woodland.

4. When adults occur, spray 90% trichlorfon or 80% dimethoate 1000 times each.

5. During larval damage stage, spray 25% chlorfenuron No.3 1000 times solution or spray 25% Mozhijing WP 1500-2000 times solution.

In order to prevent diseases and insect pests of white ash seedlings, winter tillage, soil disinfection, seed selection, seed disinfection, rational fertilization, timely early sowing and management should be carried out. If pests and diseases are found, they must be eliminated as soon as possible to ensure the healthy growth of ash trees.