Symptoms: The incidence of the site of the disease is more fruit pods, fruit ketones also have the disease. At the beginning of the disease, there are black dots on the surface of the young fruit, and then gradually expand. From July to August, they grow into round black spots with a diameter of about 1 mm. The lesions are grayish-brown and corked to varying degrees. Cracked, black halo or green halo outside the lesion. With the intensification of the disease, several lesions are connected into pieces, which greatly affect the appearance quality and seriously affect the economic value. The lesions only occur on the surface of the skin and do not harm the flesh, and the lesions do not expand and spread after harvest and during storage. Incidence pattern: young fruit is infected before bagging, and the general year begins in mid-June. From July to August, the fruit speed is long and the respiratory intensity increases. With the increase of temperature and the arrival of the rainy season, the temperature and humidity of the micro-environment within the bag Increased, the incidence rate will also increase. After the rain, the onset is rapid and the hazard is serious. The incidence rate is positively correlated with the precipitation. Pear orchard with high canopy closure and poor ventilation has a high incidence of black spot disease. The worse the breathability of the fruit bags used is, the higher the incidence rate is. Causes of the disease: Existing studies have shown that the infection of Alternaria alternata and Trichoderma spp. is the main cause of dark spots. The above-mentioned weak parasites are widely found in living tissues, deciduous (fruit), dead branches, soil, and air in pear orchards. Usually, they rarely cause harm. However, when the pear fruits are bagged, the bags are relatively dark and moist, especially near The water is easy to accumulate at the loach, which is conducive to the survival and infestation of the weak parasites. The bacteria invade the skin pores and cause damage. Prevention: 1. Agricultural control. Clear the dead branches, fallen leaves, and weeds in the park; correct pruning and reasonable load; cultivate well-ventilated, fully-illuminated trees and maintain a strong tree vigor. 2. Chemical control. 1 Spray 3 to 5 Baume degrees lime sulfur before germination. 2 before bagging: 25% Amizyme Suspension 1500-2000 times, 80% Daoxue 1000-times, 80% EDP WP 800 times, 40% Nova Emulsion 10000 times. 12.5% ​​of diniconazole WP 2000 times, 1:2:200 Bordeaux and thiophanate methyl, carbendazim, etc. In recent years, production practices have shown that 25% of Ami-Silda suspension concentrates have significant control effect from 1500 to 2000 times, and application of 1-2 times before bagging can effectively control the incidence. According to the experience of Baoding and other pear producing areas, the use of the lower-priced domestic pharmaceutical “Love†(mixture of chloramphenicol) can also receive good control effects. The use of thiophanate-methyl, carbendazim and other agents, in combination with B-aluminophosphate, can effectively control the incidence. Stainless Steel Sink,Hospital Operating Room Sink,Medical Wash Basin,Hospital Steel Sink Taizhou Gaogang District Dixin Medical Equipment Co., Ltd. , https://www.dixinmedical.com