Cucumber scab is a destructive disease How to control cucumber scab

Cucumber scab, a fungal disease, is one of the destructive diseases of cucumber in greenhouse. Once it happens, we should pay close attention to prevention and control. If prevention and control is not timely, economic losses will be great. Cucumber scab can occur at relative humidity of about 90% and temperature of 9-30℃. Scab pathogen invades cucumber from epidermis, stomata and wounds. The existence of water droplets on the film and leaves of cucumber in shed is an important condition for the occurrence of scab. Shed humidity, weak light, watering after continuous cloudy days, serious disease. The pathogen of scab exists in the form of mycelium in the greenhouse, which is the primary source of infection; it can also attach conidia to the surface of cucumber seeds or lurk in the seed coat to make cucumber seeds carry bacteria. Seed bacteria can infect cucumber seedlings, and cucumber seedlings with bacteria will soon develop disease after planting.

cucumber scab

Control methods:

1. Select cucumber varieties with disease resistance.

2. Cucumber seeds should be soaked in warm water at 55~60℃ for 15 minutes or soaked in 500 times solution of 50% carbendazim wettable powder for 20 minutes, rinsed with water and then germinated.

3. Strengthen management: under the condition that the temperature is guaranteed, try to release air and remove moisture, reduce leaf condensation, and inhibit the germination and invasion of scab bacteria; irrigate frequently with small water in winter, and do not flood with large water; wipe the shed film frequently to increase the light transmittance.

4, with 45% chlorothalonil smoke agent 300g/mu night fumigation shed about 8 hours.

5. At the early stage of cucumber scab disease, leaf spray of 10% difenoconazole water dispersible granule 1500 times, 40% flusilazole 7000 times, 12.5% myclobutanil EC 1500 times, 62.25 myclobutanil·mancozeb WP 1000 times can be used to control cucumber scab disease, depending on the disease interval 5-7 times.