Symptoms
Apple leaflet disease mainly occurs in new shoots. The incidence of general orchard is 10%~20%, and the serious 50%~60%. The diseased shoots sprouted later, the internodes shortened, the apical leaflets clustered, the leaves were abnormally narrow, the texture was hard and brittle, the leaves were yellow-green, the leaf margins were upward, and the leaves were not flat. In severe cases, the diseased branches might die. The flower buds of the diseased branches are obviously reduced, the flowers are small, and it is not easy to take fruit. The result is small and deformed and unbearable. The roots of the first diseased tree are stunted, and the old diseased tree has root rot. The diseased tree is weak and weak, the hair is weak, the canopy cannot expand, and the yield is significantly reduced.
cause
1. Insufficient zinc fertilizer in the soil, excessive phosphorus fertilizer affects the absorption of zinc, zinc in the alkaline soil is fixed, heavy orchard and other causes cause zinc deficiency and cause lobular disease.
2. Root damage or death due to root disease, soil water accumulation and improper operation of agriculture, or root growth due to long-term use of herbicides, the branches of damaged roots are prone to lobular phenomenon.
3. Lobular disease occurs mostly in the dormant period when the branches are damaged and the branches are trimmed to cause wounds. In particular, the branches are three or four strands, and only one of the lead branches is left as a leaflet. In addition, due to the freezing of the winter season, the nutrient reflux is difficult in spring, and the lack of nutrition will also form leaflets.
4. In winter, when the scissors are too much, the slash is too large, and there are mouth injuries, mouth wounds, etc., which seriously weaken the growth potential of the backbone branches, causing changes in physiological functions and causing lobular disease. In the summer shearing, the ring stripping is too wide, the stripping protection is not enough, or the tree body is short of water, etc., so that the peeling healing degree is poor, and the leaflet phenomenon occurs. The biggest difference between such leaflets and zinc-deficient leaflets is that the symptoms appear on individual plants or individual backbone branches, and 2~3 strong new shoots can be extracted in the area below the large slash or ring-striping, mostly hidden. The buds sprouted, while the branches of the zinc-deficient lobular plants were more difficult to germinate.
5. The diseases of rot, dry rot or rough skin disease are serious, the lesions are large, the healing is difficult, the bark is damaged, the nutrition transportation is affected, and the leaflet phenomenon also occurs.
Prevention
1. Adding alkaline fertilizer to acidic soil, combined with deep-expanding and deepening in autumn, applying plant straw and green manure to improve soil permeability and improve soil aggregate structure.
2. The use of organic fertilizer can not only supply the essential nutrient elements for fruit tree growth, but also improve the soil microbial living conditions, which is conducive to the release of insoluble nutrients in the soil, especially in sandy land orchards.
3. The application of zinc in soil should be mixed with organic fertilizer to reduce the fixation of zinc by soil.
4. Spray zinc fertilizer before and after germination to promote the growth of branches and leaves and prevent the occurrence of lobules. At the same time, it is necessary to avoid applying too much phosphate fertilizer to the leafy trees. Whether it is soil application or leaf spray, it should be staggered to avoid reducing fertilizer efficiency.
5. Spring fruit trees should be timely watered before germination, so that the soil is not dry, so as to promote the absorption of zinc by the roots of fruit trees. During the growing period, depending on the dry and wet conditions of the soil, the water is properly irrigated, and the rainy season is paid attention to the drainage to prevent the occurrence of mites and induce lobular disease.
6. When pruning the lobular tree, first of all, the lobular diseased branches with less sparse branches should be especially avoided to cause the mouth injury, otherwise the lobular phenomenon will be aggravated. For branches with leaflets, the posterior branches must be restored to normal growth and then gradually removed. Secondly, reduce the short-cut peripheral branches, otherwise it will increase the competition of the prosperous parts and unfavorable growth of the weak branches. In addition, do not pull the branches of the lobular disease tree to avoid injury of the guided tissue, affecting the high-level transportation, leading to the reduction of apex nutrients and increasing the degree of lobular disease.
7. For fruit trees that are difficult to heal by damage to the bark due to ringing or disease, etc., they can be bridged. (Li Wu)
Piping Accessories,Piping Tool Accessories,Pipe Fitting Accessories,Automatic Suction Water Filter
Jiangsu Hida Marine Valve Co., Ltd , https://www.haidavalve.com