Six points should be grasped in winter management of topdressing, pruning, anti-freezing, disease and pest prevention of apple

Apple overwintering management

Topdressing base fertilizer. Base fertilizer refers to the combination of organic fertilizer and non-base fertilizer, the combination of nitrogen, phosphorus and potassium, and the combination of major elements and trace elements. The amount of fertilizer application should be determined by the size of the apple tree, the yield, the tree strength and the soil fertility. Generally, for every 50 kg of apples, it takes 2 kg of pure nitrogen, 0.5 kg of phosphorus, 1 kg of potassium, 100 kg of ring fertilizer and 0.25 kg of urea.

Pest control. Advocate physical trapping and killing insects. Tie grass handles or broken sacks to the big branches of apple trees to trap insects to pupate over the winter, and then concentrate on killing them. The second is to remove the stiff fruit, cut off the branches of diseases and insect pests, clean up the withered branches, fallen leaves and weeds in the garden, and concentrate on burning or deep management, so as to reduce the source of diseases and insects. Then there is drug control. After picking apples, the whole garden is sprayed with fungicides and insecticides. Scrape off the old bark in time, burn it centrally, and disinfect it with 5-degree stone-sulfur mixture or 1% copper sulfate solution after scraping. If the disease is serious, after defoliation, the whole tree spray wheel disease net 800-1200 times liquid or 10% agricultural resistance 120, can kill winter insects.

Dig deep to improve the soil. Deep ploughing can improve the physical status of soil water, fertilizer, gas and heat, keep the soil fertile and soft, and create favorable conditions for root growth. At the same time, the overwintering cocoons and pathogens in the soil were exposed to death. Deep ploughing can be combined with fertilization, the appropriate depth of 30~60cm, heavy clay, can add an appropriate amount of sandy soil; sandy orchard, can be mixed with a small amount of clay.

Safe and anti-freezing. First, the stem is painted white to slow down the upheaval caused by direct sunlight in the apple tree, preventing sunburn and freezing. The whitening agent is made of 10 parts of quicklime, 1 part of sulfur, 10 parts of water and an appropriate amount of adhesive, which should be thickened to the sunny side. Second, in addition to spraying potassium dihydrogen phosphate and painting white on the leaves of apple trees in cold areas and shady places, methods such as covering grass, covering plastic film, laying grass on site, laying plastic film, soil cultivation, antifreeze, sealing and cutting oil of fruit trees can also be used to prevent frost damage.

Anti-rot disease. Control methods: ① should strengthen cultivation management, increase application of organic fertilizer, store nutrition, avoid partial application of nitrogen fertilizer and late irrigation. In orchard operation, shears, saws, ring cutters and other tools should be operated once and disinfected once to prevent infection. ② can remove and destroy diseased branches, diseased skins and withered piles in time, and reduce the pathogens. ③ scraping must be done thoroughly, collect and scrape off the diseased body, take it away from the orchard, deeply manage or burn it. After scraping, it is protected by disinfectants such as stone-sulfur mixture residue and bacteriolysis.

Trim at the right time. If you cut it too early, the cut will be easily damaged by freezing and form a dry pile; too late pruning will weaken the tree potential and affect the yield. Therefore, adult and strong trees should be cut early, while young and prosperous trees and apple trees damaged by diseases and insect pests should be cut late. The apple orchards with fertile, flat soil and good irrigation conditions should be cut early, while those in barren land, mountains and hills, sandy beaches and apple orchards with high groundwater level should be cut late. The hillside garden should be Yang before Yin. The cut on the negative side should be coated with antifreeze.