Symptoms of pear leaf blight : mainly damage to leaves and fruits, the leaves are infected, the young leaves produce reddish-purple small spots on both sides, diameter 1-3 mm, the lesions gradually expand to fusion, the color turns dark brown, and some A chlorotic halo is formed, which eventually leads to necrosis or yellowing of the diseased leaves. When the pear is ripe, only a small amount of leaves remain on the top of the tree, causing the tree to weaken and the yield to decrease. When the fruit is infected, the original diseased leaves are not significantly different from the healthy leaves, and then the fruit grows up, and the lesions are sunken or the fruits are dry. New spot infections can be seen in purple-black spots. These small spots fall off in the next year, so no lesions are seen on the biennial branches. The pathogenesis of pear leaf blight: the pathogens overwinter on the ulcer plaque of diseased leaves or shoots with ascospores or conidia. In the second year, the germs mainly spread by rain or irrigation water. When the humidity is relatively high, the ascospores infest the infection, and after 7 days, the symptoms are manifested. Under the condition of 10 degrees, the infection of the bacteria takes 12 hours, at 20~25. It takes 8 hours to get the degree, and it is easy to be popular in warm winter and spring. Pear leaf blight prevention and control methods: (1) in the winter and spring, timely remove the diseased plant residues, litter, concentrated burning or deep burial. Apply organic fertilizer and chemical fertilizer to avoid partial application of nitrogen fertilizer and improve the disease resistance of fruit trees. Deep digging and exposing the soil reduces the spread of overwintering bacteria. (2) The row spacing of the plant is suitable to facilitate ventilation and dehumidification. Ceiling lights are a common lighting device with characteristics and attributes such as bright and uniform, space saving, safety and reliability, diversified design, energy conservation and environmental protection, dimming function, and intelligent control LED ceiling lights ,Customize multiple ceiling lights,Customized ceiling lights Hanghong Lighting Co., Ltd , https://www.sdhhzm.com