Walnut planting:

1. Seed selection: Select mature trees (30-50 years old) with strong growth, no pests and diseases, and full kernels as mother trees for seed collection. The nuts can be harvested when their green skin turns from green to yellow and cracks. To ensure seed quality, seed walnuts should be harvested 3-5 days later than commercial walnuts. Walnuts sown in autumn can be sown with green skins, while walnuts sown in spring need to be peeled off and then dried and stored.

2. Seed treatment: Autumn sown seeds can be sown directly without any treatment. When sowing in spring, seeds should be soaked before sowing to ensure germination. Commonly used methods are as follows:

1. Cold water seed soaking method. Soak in cold water for 7-10 days, change the water once a day, or place the sack containing walnut seeds in running water to allow it to absorb water and expand to crack, and then you can sow.

2. Soaking seeds in warm water. Place the seeds in a warm water tank at 80°C, and then stir continuously to allow it to naturally cool down to room temperature. Soak for 8-10 days, changing the water every day. After the seeds swell and crack, take them out and sow them.

3. Sowing

1. Sowing time: autumn sowing and spring sowing. Autumn sowing should be carried out before the soil freezes (late October to late November). Spring sowing should be carried out immediately after the soil thaws (mid-March to early April).

2. Sowing method: First make a 1 meter wide seedbed, sow 2-3 rows in each bed, with a row spacing of 20-30 cm and a plant-to-plant spacing of 10-15 cm. The method of placing seeds is to place the seed suture line perpendicular to the ground and place the seed tip to one side, which is beneficial to seedling emergence; cover the seeds with 5-10 cm of soil after sowing.

4. Fertilization:

1. Base fertilizer. Basal fertilizer should be applied as early as possible, and should be completed after harvesting and before leaf fall. Apply 100 to 200 kilograms of high-quality organic fertilizer to each adult tree.

2. Top dressing. The appropriate periods for top dressing are before flowering, when young fruits are enlarging, and when fruits are hard cored. Generally, 0.8 to 1 kilogram of Tianji brand nitric acid phosphate fertilizer is applied to each plant at a time.

3. Spray fertilizer on the leaves. Fertilizer spraying periods are during the flowering stage, shoot growth period, flower bud differentiation stage and after harvest. Commonly used fertilizer spraying types are 0.1% to 0.2% boric acid, 0.5% to 1% ammonium molybdate, 0.3% to 0.4% Copper sulfate, etc.

5. Disease prevention:

1. Walnut branch blight: This disease is a fungal disease. It mainly damages branches and causes them to die. Generally, the plant damage rate is about 20%, and in severe cases, it can reach 90%. The disease mainly affects tree growth and yield.

The symptoms of the disease are that after the 1-2-year-old branches or side branches are damaged, they gradually dry up from the top to the main trunk, and the leaves turn yellow and fall off. Dense small black spots appear on dead branches. When the humidity is high, mucus flows out and black tumor-like protrusions are formed. The fungus overwinters on diseased branches and invades through wounds. The disease only harms weak trees.

2. Pests: aphids, hawkmoths and other leaf-eating pests.

Prevention and treatment methods: destroy, remove diseased branches, and burn them intensively. The drugs, prevention and treatment time and agents used are the same as those for the prevention and treatment of walnut anthracnose.

Extended information:

Another method of propagating walnut seedlings: grafting

Steps:

1. Use this anvil or iron as the rootstock Walnut seedlings are 1 to 2 years old.

2. First, layer the seed sand for more than 60 days, then take it out and sow it in spring.

3. The spacing between rows is 30 to 40 cm, the spacing between plants is 12 to 15 cm, and the soil covering is about 5 cm. When sowing, keep the suture line of the seeds perpendicular to the ground to facilitate the smooth growth of the radicle and buds.

4. The suitable period for branch grafting is between the beginning of spring and rain, when the sap begins to flow and the top buds of the rootstock have sprouted.

5. The suitable period for bud grafting is around the spring equinox, when the rootstock begins to shoot and before the terminal buds unfold their leaves, and when the bark is easy to peel off.

6. After grafting, the joints and scions should be covered with plastic bags and packed with moist sawdust for insulation. The grafting survival rate is over 95%.

7. Use walnut cotyledon seedlings for grafting. When the seed buds will develop true leaves, cut off the anvil buds 1 cm above the cotyledon and split them. After grafting, place them in a healing pool or a simple greenhouse. After surviving, the seedlings can be transplanted into the field with a survival rate of more than 80%, which can shorten the seedling raising time.

Reference: Baidu Encyclopedia - Walnut

Baidu Encyclopedia - Walnut