Key Technical Points for Preventing Physiological Diseases of Autumn Tomatoes
Early blight: After onset, concentric ring-patterned lesions appear on the leaf surface, dark brown, water-soaked. Before and after onset, spray with a 500-fold dilution of 70% mancozeb wettable powder, or a 400-fold dilution of 75% chlorothalonil wettable powder, once every 7 days, for 3 to 4 consecutive sprays.
1. Preventing blossom-end rot: Ensure a balanced combination of nitrogen, phosphorus, potassium, and trace elements in fertilizers, applied in planting holes. Control nitrogen fertilizer application, water reasonably, and keep the soil moist.2. Preventing sunscald: Increase the application of organic fertilizer to improve the soil's ability to retain nutrients and moisture. When removing growing points, leave 2-3 leaves above the top truss to help cover the fruit and reduce sunscald.
3. Preventing fruit cracking: Water frequently, drain after the beds become moist, and keep the soil moist. Prune at the right time and keep fruit trusses hidden among the branches and leaves to prevent direct sunlight on the fruit.
4. Preventing deformed fruit: Use growth regulators correctly; the concentration of 2,4-D should not exceed 30 mg/kg, and the concentration of Tomatotone should not exceed 40 mg/kg. Control the amount of nitrogen fertilizer applied, combine with phosphorus and potassium fertilizers, increase boron fertilizer application, and keep the soil moist, neither too dry nor too wet.