Zucchini, also known as courgette or summer squash, is a refreshing vegetable with high nutritional value, especially rich in nutrients like vitamin C and glucose. It is widely cultivated in many regions. However, various diseases and pests can occur during the cultivation of zucchini. Let's learn about the methods for preventing and treating Sclerotinia stem rot, a common disease.
Methods for Preventing and Treating Sclerotinia Stem Rot
1. Symptoms
Sclerotinia stem rot mainly affects the vines and stems of zucchini. When the vines are infected, the disease begins at the remnants of the flowers, causing the vines to become diseased. The infected remnants of flowers initially show signs of water soaking and rot, followed by the growth of white mycelium, with black fungal cores scattered in the middle. Stem infections start with water-soaked lesions, which then turn brown and soft, accompanied by the growth of white mycelium.
2. Prevention and Treatment
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Agricultural Measures: After harvesting zucchinis, deep plowing should be done promptly, followed by crop rotation to bury the fungal cores. Cultivate zucchinis on raised beds with plastic mulch and drip irrigation. Timely removal of diseased leaves, flowers, vines, old leaves, and yellow leaves, which should be disposed of off-site. Maintain proper temperature and humidity in the greenhouse, with daytime temperatures controlled at 28°C and relative humidity below 65%.
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Physical Measures: Before sowing, soak the seeds in a 10% saline solution mixed with 800-fold dilution of the new high-fat film for 2-3 times to eliminate fungal cores and reduce sources of infection.
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Soil Disinfection: Before planting, mix 1 kg of 40% pentachloronitrobenzene with 20 kg of fine sand per acre and rake it into the soil for soil disinfection.
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Chemical Treatment: At the initial stage of disease onset, timely spray with 1500-fold dilution of 50% carbendazim wettable powder, or 1500-fold dilution of 50% carbendazim, or 1000-fold dilution of 50% vinclozolin, or 500-fold dilution of 75% chlorothalonil, or 1000-fold dilution of 95% propiconazole, or 1000-fold dilution of 72% mancozeb·zinc, or 800-fold dilution of 50% carbendazim, or 500-fold dilution of 40% azoxystrobin, or 1000-fold dilution of 50% cyprodinil wettable powder. Repeat every 7-8 days for 2-3 times. To reduce greenhouse humidity, you can also use 10% smoke fumigants per acre each time, or 250 grams of 45% chlorothalonil smoke fumigants in the evening, followed by ventilation the next morning.
Above are the key points for preventing and treating Sclerotinia stem rot in zucchinis, mainly focusing on environmental control, physical prevention, and combined chemical control. When using chemical treatments, attention should be paid to safe and alternate use of drugs.
