Seed treatment of Robinia pseudoacacia
Seed soaking: Robinia pseudoacacia seed coat is thick and hard with poor water permeability. In order to improve the germination rate, shorten the germination period and orderly emergence, seed treatment must be carried out before sowing. Pour hot water of about 55℃ into a container filled with seeds, stir while pouring until it is not hot, soak it overnight, and take out the swollen seeds with a sieve. The remaining unexpanded hard seeds were treated with water at about 85℃ for 65438 0 ~ 2 times until most seeds expanded. If there are hard seeds that are difficult to swell, you can wrap them in gauze, put them in boiling water 10 s, quickly lift them up, and then soak them in cold water for one night.
Accelerating germination: In order to make the seeds germinate evenly and emerge quickly, it should be accelerated before sowing. Put the swollen seeds in a bamboo basket, cover them with a wet towel or a wet cloth, put them in a sunny or warm place, wash the seeds with clear water twice a day for about 5 days, and sow them when 1/3 seeds crack white.
Sowing: Sowing is usually carried out in March, when the temperature is low, which is conducive to seed germination. Before sowing, the container filled with nutrient soil is soaked with water to make the soil sink. Some containers are filled with nutrient soil. Tamp a hole with a stick and sow the germinated seeds in containers, and sow 3 seeds in each container. Then spread fine cotton sand evenly on the container and cover it with soil, so that you can't see the seeds.
Tending management of Robinia pseudoacacia seedlings
1. Nursery management When the seedlings grow to 3 ~ 4 cm, occasionally remove the sick seedlings, and the over-dense seedlings are sparse. When the seedling grows to 10 ~ 15 cm, the seedling is fixed. Each linear meter is about 10 seedlings, and the seedlings must be staggered when they are fixed in two rows. About1.20 thousand seedlings per mu.
2. After the seedlings are in full bloom, they should be irrigated according to the soil moisture, 2 ~ 3 times a year. If the seedlings don't grow in autumn, they should be watered with 1 times antifreeze before overwintering. Topdressing 1 time, per mu 10 kg in early June. Irrigation 1 time after fertilization.
3. Spraying 0.5% ~ 1% Bordeaux mixture or 1% ~ 2% ferrous sulfate at seedling stage to control rice sheath blight, and spraying 1 time every 10 day. Control of aphids with 40% dimethoate 800 times solution. In order to make the seedlings grow in a balanced way, 1 twig was cut off at the end of July. Cut more big seedlings and less small seedlings, and the height after cutting seedlings should not be less than 80 cm.
4. Before the seedlings leave the nursery, cut them dry at a distance of 15 ~ 20cm from the ground surface, and then use a U-shaped seedling plow to lift the seedlings, and the depth of lifting the seedlings should not be less than 18 ~ 20cm. You should pick seedlings while walking, and keep up with the seedlings that can't be planted that day.
Robinia pseudoacacia plastic pruning
Shaping: Under natural growth, Robinia pseudoacacia has strong branching and vigorous growth, often forming a broad oval crown, but most of the trunks are low and have too many branches, forming a "small old tree". Shaping is to straighten the trunk. The lateral branches competing with the trunk should be pruned from the winter of 1 or the spring of the second year after planting, and the height of the trunk should be more than 6m after 5-8 years, reaching the standard of civil timber.
Pruning: The time and quantity of pruning depends on the purpose of afforestation. General afforestation should be pruned after the young forest is closed; In order to cultivate tall trunks and prevent excessive shading, the surrounding green spaces and shelterbelts should be trimmed properly in the first three years. Robinia pseudoacacia under 2 years old has a lower trunk. Generally, strong and upright branches are selected as the trunk, and the rest branches are drained according to different conditions. After the trunk is pruned to a certain height according to the ratio of crown to stem, the thick competitive branches, overgrown branches, upright branches and some over-dense side branches, drooping branches and dead branches in the upper part of the crown are drained.
Pruning sprouting strips: after pruning, the long branches on the trunk or main side branches should be cored or cut off; For sparse branches at the base of trunk and the top of trunk heading in winter, sprouted new buds and buds should be cut off as soon as possible. Pruning should be carried out in summer, preferably from early June to early July, which has the advantages of less trauma and quick healing, and generally does not sprout a large number of branches, which is beneficial to the growth of young trees.