Notes on the use of drugs for prevention and treatment of root swelling of Chinese cabbage

Chinese cabbage root swelling disease refers to the formation of tumors of different sizes and shapes in the root of Chinese cabbage. The tumor is smooth in the early stage, cracked and rough in the later stage, and is easy to infect bacteria after cracking. Root swelling not only harms cabbage, but also a variety of cruciferous crops. Root swelling disease can be damaged in the seedling stage of Chinese cabbage and die when it is serious. The pathogen contains a large number of dormant sporangia in the dilated cells of the main diseased roots of crops during the overwintering or summer in the soil. The spores are scattered in the soil after the diseased tissue is decomposed and can generally survive for 6-7 years. Conditions for the onset of Chinese cabbage and swollen disease soil temperature and humidity. The pathogen can occur in the range of 6-30 degrees Celsius and 50% Mel 98% of the field capacity; soil pH. The bacteria is suitable for acid soil environment, and too much acid fertilizer is applied to the land. Pesticide control method of swelling disease of Chinese cabbage soil disinfection was carried out by spraying or disinfecting the seedbed with 75% dimethazone soluble powder and 1000 times carbendazim wettable powder, and the acid soil in the field was modified by the application of plant ash and alkaline organic fertilizer to alleviate the occurrence of swelling disease. After seed treatment, 50% carbendazim wettable powder plus 58% Manganese-zinc 400 times solution soaked the seeds. Seven days before seedling emergence, 50% carbendazim wettable powder plus 75% chlorothalonil wettable powder 600 times liquid spray was used to prevent germs from being brought into the field. To strengthen field management, drainage ditches must be unblocked, so that irrigation can be drained, there is no excessive stagnant water, and the field capacity is controlled not to exceed 50%. Timely removal of diseased plants found that diseased plants should be removed and burned in time, and lime should be scattered around the disease points to prevent the spread of germs. After the onset of the disease, Chinese cabbage was irrigated with 58% Ruidu mold manganese zinc, 50% carbendazim wettable powder and 75% dimethazone soluble powder 600 times, 0.5 kg per plant. As the disease is spread by soil, once it spreads, it will cause serious consequences. Therefore, attention must be paid to strengthening prevention and control.