When do walnut trees usually be planted? What are the methods of artificial pollination?

Walnut is one of the four major nuts, its trees not only have a certain ornamental value, but also a good material for construction, furniture and other processing. Walnut trees are planted in many places in China. In order to increase their fruiting rate, artificial pollination is often used. Let's take a look at when walnut trees are usually planted. What are the methods of artificial pollination?

When do walnut trees usually be planted?

Fruit growers who have planted walnut trees know that they sprout and grow leaves in spring, blossom in May and mature fruit in October, so walnut trees are usually planted before sprouting in spring or after fruit ripening in autumn. Spring and autumn are the best times to plant walnut trees. For example, spring planting should be carried out before the seedlings sprout after the soil is thawed, while autumn should be planted after the Beginning of Autumn and before the soil is frozen.

Walnut trees are not strict with environmental conditions. They can be planted in areas with an average annual temperature of 9-16 ℃, an annual rainfall of 500-800 mm, and an altitude of 600-1200 meters. Walnut has a wide range of adaptability to soil, but because it is a deep-rooted fruit tree with weak resistance, it is more suitable to choose loam with deep, fertile and strong water retention. Walnut is a light-loving fruit tree, which requires sufficient light, so it is better to choose the south slope when building a garden in the mountains.

What are the artificial pollination methods of walnut trees?

Different pollination methods can be used for walnuts with different management levels and different varieties.

1. Powder spraying method

For short early-bearing walnut young trees, pollinator can be used to pollinate, or medical throat sprayer can be used instead. When pollinating, put the pollen into the glass bottle of the pollinator and spray it in the middle and upper part of the crown. Pay attention to the spray head leaving the stigma 30cm or above.

2. Spray method

The pollen liquid was prepared by mixing pollen with sugar and water according to the ratio of 1 ∶ 50 ∶ 3000 or ∶ boric acid ∶ water to 1 ∶ 0.2 ∶ 3000. The pollen liquid was sprayed evenly on the crown at 9: 00: 10: 00:00 or 15: 00 at 16: 00. It can also be combined with foliar fertilizer spraying at the same time, using pollen: granulated sugar: urea: water 1 ∶ 50 ∶ 10 ∶ 3000 nutrient solution spray. Spraying urea ∶ boric acid ∶ water ratio 0.2 ∶ 0.3 ∶ 100 foliar fertilizer every 15 days after stigma withering for 3 times could promote the rapid expansion and growth of fruit and enhance fruit quality.

3. Shaking powder method

Mix pollen and starch in a ratio of 1 ∶ 10, put them into 2-4 layers of gauze bags, seal the mouth of the bag, tie it to the bamboo pole, and shake it in the wind above the crown. Under normal climatic conditions, artificial pollination can increase the fruit setting rate by 15% to 25%. In case of abnormal weather such as low temperature, overcast and rain, strong wind and frost, or walnut trees with secondary flowering habits, artificial pollination can increase the fruit setting rate by 20% and 35%.

4. Hanging powder method

The male inflorescence which is about to disperse powder is collected, and every 4 to 5 is a bunch, hanging on the top of the crown, allowing it to disperse powder freely.