Symptoms can be onset from seedlings to adult plants. Seedling disease, cotyledons were water-stained and quickly died. In the adult stage, the disease mainly damages the leaves and begins to develop from the edge of the leaves, forming an inwardly expanding “V†shaped lesion with a yellow-brown lesion and a pale yellow edge; the roots suffer, the vascular bundles turn black, and the internal dry rots, the condition In severe cases, the whole plant died of wilting. Hospital/Clinic/Drugstore Equipment Lightweight Wheelchair,Folding Wheelchair,Manual Wheelchair,Portable Wheelchair Surgimed Medical Supplies Co.,Ltd , https://www.surgimedcn.com
Black rot is a disease caused by the infestation of bacteria of the genus Xanthomonas. The pathogenic bacteria overwinter on seeds, plants or diseased bodies. Insects and agricultural operations can also spread diseases. Seed carriers can spread long distances and are the main source of morbidity. If the seed with the fungus is sown and the seedlings are unearthed, the pathogen invades the water hole at the edge of the cotyledon of the seedling and causes the disease of the seedling to gradually spread to the vascular bundle, causing the onset of the whole plant. Bacteria in the soil can be transmitted to the leaves through rainwater and irrigation water. Invasion occurs through the stomata and water holes in the leaves. First, a small number of parenchyma cells are infiltrated into the soil and the system quickly invades the vascular bundles to cause systemic infection. High temperature and high humidity are conducive to the onset of disease. Temperatures can affect the disease from 5°C to 39°C. The optimal temperature for onset is 25°C to 30°C, and the relative humidity is above 95%. Dew condensation on the leaves and sprinkling of water on the leaf edges are conducive to bacterial invasion. Premature sowing, low-lying land, soil viscosity, excessive watering, continuous cropping with cruciferous vegetables, application of unfamiliar fertilizers, and heavy pests are important.
Prevention and control measures Seed selection and seed treatment: Select disease-free strains for seed retention; soak in seeds with warm water at 50°C for 20 minutes before sowing, or soak for 2 hours with 1000 times agricultural streptomycin. When live broadcast, 50% of Fairchild can use 40% seed weight seed dressing. Strengthen field management: serious disease plot rotation. Timely sowing, application of manure, drainage in time after rain, to avoid excessive drought, and early removal of diseased leaves in time, complete removal of diseased bodies at the time of harvest, reducing the initial source of field dip. Chemical control: In the early stage of disease prevention and treatment in time, use 20010-6 agricultural streptomycin solution, or 10010-6 neomycin solution, or 60% chlorothalonil wettable powder 600 times, or 1:1:200 to 1 : : 240 times Bordeaux mixture, or 77% can kill WP 500 times. The above agents can be used alternately to receive good control effect.