Seed breeding of Robinia pseudoacacia

Robinia pseudoacacia is a pioneer tree species in barren mountain afforestation, which has the characteristics of barren tolerance, drought tolerance, fast growth rate, wide use and so on.

1. Nursery land selection and seedling preparation should choose flat topography, good drainage, deep soil layer, fertile neutral sandy loam, and land with irrigation conditions. Vegetable plots should not be selected, and continuous cropping should not be selected. After the nursery land is selected, ploughing will be carried out in autumn with a depth of about 30 cm. Rake fine rakes in early spring and apply 5000 kilograms of rotten barnyard manure per mu. The poisonous soil made from phoxim EC should be applied during soil preparation to control underground pests.

two。 The seed coat of Robinia pseudoacacia is thick and hard, and the outer skin contains pectin, which is not easy to absorb water. Ten days before sowing, put the seeds in a jar, pour in 90 ℃ of hot water, and stir until they are not hot. After soaking for 24 hours, remove the floating matter and bad seeds, and then use a fine-eyed sieve to separate the swollen seeds from the unswollen seeds. The unswollen seeds can be retreated with 90 ℃ hot water for 1 or 2 times. Pour the swollen seeds into the basket, cover them with wet sacks, and place them in a warm place to germinate. In order to prevent the seeds from sticking and deteriorating, the seeds should be washed with clean water once or twice a day. After about 1 week, the seeds can be sown when the tip of the seeds is exposed.

3. Sowing and sowing around the middle of April, when the temperature reaches 16 ℃. The yield of seedlings per mu is about 10,000 plants and the amount of seeds used is 5 kg. Generally use ridge sowing, ridge spacing of 70 cm, double-row sowing. If the soil is dry, it is necessary to sow seeds by sitting on water. When sowing, spread the seeds evenly into the ditch, cover the soil with a thickness of 1 to 1.5 cm, and then gently press the seeds once so that the seeds are in close contact with the soil.

4. Seedling tending management when the seedlings grow to 3-4 cm, occasionally remove the sick and weak seedlings, open the overdense seedlings, and fix the seedlings when the seedlings grow to 10-15 cm. About 10 seedlings are retained for each extended rice, and must be staggered when double-row seedlings are fixed. There are about 12000 seedlings per mu.

After the seedlings come out, they should be irrigated timely and appropriately according to the soil moisture, irrigating for 2 or 3 times a year. If you can't get up seedlings in autumn, you should irrigate one time of antifreeze water before overwintering. Urea can be applied once in the first ten days of June, 10 kg per mu. Water should be irrigated once after fertilization.

Spray 0.5%-1% Bordeaux solution or 1%-2% ferrous sulfate once every 10 days for prevention and control of standing blight at seedling stage. 40% dimethoate 800 times solution is used for aphid control. In order to make the seedlings grow evenly, the seedlings were cut once at the end of July. The big seedling cuts more, the small seedling cuts less, and the height after cutting the seedling should not be less than 80cm.

5. Before coming out of the nursery, the seedlings are cut dry at 15-20 cm from the surface, and then ploughed with "U"-shaped seedlings, and the seedling depth is not less than 18-20 cm from the main root of the seedlings. Seedlings should be selected at random, and seedlings that cannot be planted on the same day should be planted in time.