Prevention and control of leaflet disease of growing apple

Apple leaflet disease often occurs in orchards with barren soil and good water permeability. Due to low zinc content and loss of soluble zinc salt, the disease is serious; the number of watering and rainfall is large, and the loss of soluble zinc is large; excessive use of nitrogen fertilizer leads to an increase in zinc requirement of trees; in saline-alkali soil, zinc is easy to be fixed and can not be absorbed by roots. In addition, the soil is heavy, the active soil layer is shallow, the root system is underdeveloped, and the lobular disease occurs seriously. Therefore, increasing the supply of zinc salt or releasing fixed zinc is an effective way to prevent and cure the disease. The specific practices are as follows:

Increasing the application of organic fertilizer, improving the soil and increasing the content of organic matter in the soil can reduce the soil PH value and increase the solubility of zinc salt, which is convenient for fruit trees to absorb. For orchards with poor conditions such as sandy land, clayey land and saline-alkali land, we should improve the soil by applying soil fertilizer, increase zinc and release solidified zinc, which can promote the development of root system and improve the absorption function.

Zinc application in soil and zinc spraying in plants combined with base fertilizer, 0.1-0.15 kg zinc sulfate per tree was generally effective in the second year and lasted for 3 years. For the fruit trees with leaflet disease, spraying 30 times zinc sulfate liquid fertilizer before germination has obvious effect on the prevention of lobular disease in the same year. Three weeks after anthesis, it was found that the diseased plants with lobular disease could be sprayed with 500 times zinc sulfate and 300 times urea, which had an obvious effect on reducing the disease. after spraying continuously for 2 years, the recovery rate of diseased branches was more than 95%, and the yield increased significantly.