Anti-cold and anti-freezing measures of litchi longan

1. Tree trunk whitening

Combined with the work of clearing the garden, the trunk and branches of litchi and longan were whitened once, which was not only cold-proof but also sterilized. The preparation method of whitening agent is as follows: 10 parts of quicklime, 2 parts of salt, 2 parts of adhesive (such as clay, grease, etc.), 2 parts of stone-sulfur mixture, 35 parts of water, and a small amount of targeted insecticides can also be added. First use hydrated quicklime, filter out the residue, pour in the boiled salt, and finally add stone sulfur agent, adhesive and other fully stirring. The liquid should be dry and sparse properly, and it is appropriate not to lose when brushing, not to warp after drying, and not to fall off.

2. Bandaging the trunk

The neck of the root at the base of the trunk is the weakest part of cold resistance, so before the frost comes, the trunk and main branches are wrapped with straw, and then the soil is cultivated in a high position, and the soil is removed and unbound after the temperature rises in the coming year, so as to reduce the temperature difference between day and night, thus reducing the degree of freezing damage.

3. Cultivate the soil on the tree plate

Soil cultivation and protection for young trees is the most effective and reliable method. The specific method is to take the trunk as the center to build a bread-like mound with a radius of 50 cm for young trees and more than 100 cm for adult trees, with a height of 30 cm to 50 cm. First, a layer of rice straw or plant ash is placed in the tree plate, and then covered with soil to prevent freezing and moisturizing.

4. Spraying water on leaf surface and irrigation on root.

Before the frost comes, do a good job of irrigation to increase the water content of the soil to prevent the temperature near the ground from dropping suddenly, causing frost damage. When frosting, you also need to spray water and wash the leaves before the sun comes out in the morning to prevent frostbite when the sun comes out to thaw.

5. Drug treatment

2-3 weeks before the arrival of frost, foliar spray can be carried out with antifreeze, Na's 778 cold-proof agent or other cold-proof drugs, once every 7 days, 2-3 times in succession, to improve the cold resistance of the leaf. Paclobutrazol can also be used, but can not be used continuously, so as not to affect the flowering and spring shoot in the coming year.

6. Orchard smoking

Mix weeds collected during winter clearing with turf mud and pile them in low-lying areas susceptible to frost. In the night of frost, when the temperature drops to the critical temperature of lychee and longan, the smoke is lit in the windward, and many points are set up in order to distribute evenly and grasp the ignition time, so that the smoke can cover the whole orchard before sunrise.

7. Canopy cover and smoke

In the evening when the frost comes, cover the whole canopy with film or 90% shading net, smoke after 10:00 in the evening, and remove the film the next day when the frost and snow melts. Repeated until the end of the frost, it can not only prevent frost from directly harming the tree, but also increase the tree temperature, which is the most ideal comprehensive cold prevention measure.