Control methods of black spot of soft rot tomato with sunken brown spot

Tomato black spot, also known as nail head spot and finger spot, mainly harms fruits, leaves and stems. The fruit is infected, the disease spot is grayish brown or brown, irregular to round, the disease part is slightly sunken, there are obvious edges, there are one or more disease spots of different sizes, the disease spots can be connected into large spots, black mildew on the surface, and soft rot of the diseased fruit in the later stage of the disease.

Tomato black spot

Incidence rule: the pathogen overwintered with the remains of tomato disease in the soil with mycelium or conidia and conidia. In the following spring, the conidia spread by airflow and carried out primary infection and re-infection. The parasitism of the bacteria is weak and the host range is wide. Usually the tomato plant is weak or the fruit has a wound. The pathogen likes the environment of high temperature and high humidity. The most suitable temperature for the disease is 2530 ℃, and the relative humidity is more than 85%. The susceptible growth period of tomato black spot is in the mature stage of tomato. The disease is serious in the fields with low-lying terrain, extensive management, lack of fertilizer and water, poor growth of tomato plants, and serious disease in years with high temperature and heavy rain.

Prevention and treatment measures: when the disease was mild, Aolikejing 300 times liquid was sprayed once every 7 days. When the disease was serious, 300 times liquid was sprayed once every 3 days, and the spraying times depended on the condition of tomato. ① seed disinfection: the seeds were soaked in 50 ℃ warm water for 30 minutes. ② strengthen field management: try to prevent damage to tomato plants by farming operations; scientifically regulate fertilizer and water to make tomato plants grow steadily; after harvest, clean the fields in time, plough and dry the soil. ③ chemical control: the tomato was protected by spraying from the green fruit stage, once every 7-10 days, for 2-3 times. Medicine can be used with 75% chlorothalonil wettable powder 600 times liquid, spray control.