How to use pesticides to prevent and control black mold on tomatoes
Leaf mold is a common disease on tomatoes. Although it does not directly infect the fruit, it reduces leaf function and thereby affects yield and quality. In production, farmers often report that leaf mold is difficult to control and that the effect after spraying is not obvious. The main reason for poor control is improper control methods. When applying pesticides, the following points should be given special attention...
In the early stage of the disease, targeted pesticides should be used as soon as possible. (1) Smoke agents: use 250 grams of 45% chlorothalonil smoke agent per mu, divide the smoke agent evenly into 4-6 piles, place them 30 cm from the plants, close the greenhouse film in the evening, light the smoke agent (there must be no open flame), withdraw outside the greenhouse, close the greenhouse door tightly, keep it sealed overnight, and ventilate the next morning. Fumigate once every 7 days, for 2-3 consecutive times. (2) Dust application: use 1 kilogram of 5% chlorothalonil dust per mu, or 1 kilogram of 7% yemeijing dust. In a solar greenhouse, the applicator faces south and applies the dust while moving sideways along one end of the north wall of the greenhouse: in a plastic tunnel, the applicator starts from one end of the central walkway and applies the dust while walking backward, aiming the dusting tube at the space above the tomato plants and swinging it left and right at a constant speed so that the dust is applied evenly into the greenhouse space. Generally, about 200 grams are applied per minute, moving sideways (backward) 10-12 meters. After finishing the dust application, the applicator exits through the greenhouse door and keeps it sealed overnight. Apply once every 7 days, for 2-3 consecutive times. (3) Spraying: on a sunny morning, use 200-fold dilution of 2% wuyi mycin aqueous solution, or 1:1:200 Bordeaux mixture, or 500-fold dilution of 75% chlorothalonil wettable powder, or 1500-fold dilution of 50% iprodione wettable powder, or 600-800-fold dilution of 47% jiaduanong wettable powder, or 8000-10000-fold dilution of 40% fuxing emulsifiable concentrate for spraying, and also spray the undersides of the leaves, rotating the pesticides. Spray once every 7 days, for 2-3 consecutive times. Do not spray on rainy days.