Problems and Countermeasures of inappropriate bagging of apples

  According to the survey, some fruit farmers in order to seize the market, apple bagging time ahead of schedule, Red Fuji from late September to early October in the past to early September, the earliest in late August began to pick bags. The result is that apples can't all turn green and turn green poorly. Some fruit farms are not allowed to buy high-quality fruit bags, poor shading, and paper bags resistant to rain erosion, resulting in rough fruit surface and poor greening. In addition, picking bags on rainy days and raining after picking bags, not only rough fruit surface, but also a large number of cracks, red spots, cracks, chaff and fruit green phenomenon. Especially in orchards with more than two rains within 15 days after bagging, bagged fruit is similar to ordinary fruit or better than those without bagging.   Therefore, picking bags at the right time is the key to ensure fine peel, tender flesh and smooth fruit surface. Gala apples grow in bags for not less than 80 days. Red Fuji must reach more than 100 days. When all the fruits turn green and milky white, pick the bags. It is better to pick bags in late September and early October in Jiaodong area. This time has good sunshine, less rainfall and large temperature difference between day and night, which is conducive to colouring. At the same time, double-layer paper bags with good shading, strong adaptability and rain resistance should be selected to promote fruit greening and color.

Problems and Countermeasures of inappropriate bagging of apples

  Daily fever of bagged apples is mainly caused by high temperature and drought. At the same time, it is also related to tree potential, fruit location, orchard management level, paper bag quality and improper bag picking. According to the investigation in recent years, sunburn occurs heavily in high temperature and drought years with less rainfall; it occurs lightly in years with large rainfall and uniform distribution; sunburn occurs lightly in high quality paper bags, but wax coating is not uniform, double-layer black bags and plastic bags occur heavily; orchards with more watering and less drought watering occur lightly in management, orchards with less drought watering occur heavily in autumn pruning. The occurrence of few and no branches is serious; the occurrence of weak trees is light, the occurrence of strong trees is serious; the occurrence of one-time picking bags is heavier than the second picking bags on picking bags; the occurrence of picking bags under high temperature and strong light and rainy days is the heaviest; the light causes partial whitening of fruits, and the heavy burns become brown and depression, thus losing commodity value. 

  Fertilizer and water management should be strengthened, and high quality fruit bags should be selected. When picking bags, the outer bags should be removed first, then the inner bags should be removed after 3 sunny days. It's better to pick bags from 8 to 11 a.m. and 3 to 5 p.m. Orchards should be watered once before bagging in dry years to keep the soil moist. When autumn pruning, appropriate amount of branches should be left on the back to prevent sunshine and reduce the incidence of sunburn.

  According to the investigation, the causes of poor smoothness of bagged fruits are climate factors, drought in growing period and freezing injury in young fruit period, imperfect development of epidermis and epidermis cells, over-tight cell arrangement, rain and continuous rain before fruit harvesting, rupture of cortex, rasp pattern on fruit surface, crack in serious cases, and red dot caused by coloration. The recessive pesticide damage caused by peel breakage, rust spot, red spot and black spot was caused by the use of peel stimulating agents during young fruit stage and before bagging. Thirdly, calcium deficiency was caused by incomplete development of epidermal cells, lack of cutin and wax in peel, discontinuity, poor resistance, cracks, cracks and red spots in peel. Fourthly, extensive orchard management, inadequate investment, excessive ring peeling and weakening of tree body. Orchard disease is serious; Fifth, canopy closure, poor permeability, large number of branches and leaves orchard disease is serious. 

  Water the bag three to five days before picking it. We should pay attention to increasing organic fertilizer, supplementing calcium fertilizer, promoting fruit development and sound, so as to achieve serious fruit thinning and reasonable load. Before bagging after flowering, pesticides that irritate the peel are prohibited to prevent hidden pesticide damage. For closed orchards, excessive shading branches should be removed to achieve ventilation and transparency. At the same time, it is strictly forbidden to pick bags on rainy days. Leaf fertilizers such as calcium and potassium should be sprayed on orchards that are exposed to rain after picking bags, so as to promote fruit color and reduce physiological diseases.

  According to the investigation, the main reasons for fruit yellowing and water loss are as follows: insufficient organic fertilizer and preferential application of nitrogen fertilizer; deficiency of calcium, which causes fruit chaff and cracks, and results in fruit watering and softening, especially in orchards with severe drought and water deficiency; weakness of tree body and excessive ring peeling; excessive boron poisoning and potassium, and excessive application of borax and potassium fertilizer. In orchards, boron and potassium have antagonistic effects with other elements, affecting the absorption of other elements, resulting in yellowing and discoloration of fruits. Fifth, bagging is too late, after cold dew, the temperature of bagging can not meet the requirements of colouring, and the fruits are yellowing or yellowish. On the premise of promoting tree health, scientific fertilization, supplementation of calcium fertilizer and rational use of boron and potassium fertilizer should be achieved. In drought years, it is necessary to water in time to keep orchard soil moist and prevent drought of fruit trees. At the same time, it is better to pick bags in time, in late September and early October, at the latest, 3-5 days before the cold dew.

  The skin of bagged apple is thin and tender by branch grinding. After bagging, it is easy to be damaged by branches and leaves and human, especially by branch grinding. Therefore, when apple picking bags, the frictional parts between fruit and branch should be protected to avoid fruit abrasion, and to maximize the grade rate of bagged fruits, so as to improve quality and efficiency.