Symptoms of Cucumber Bacterial Blight
The disease mainly affects leaves, petioles, stems, tendrils and fruits.
1. The leaves are infected with the disease. Initially, water-soaked spots appear on the leaf margins. After expansion, the lesions are irregular in shape, with a yellow halo on the edges, light brown in the center, and expand to the middle of the leaves.
2. When the disease is severe, large water-soaked lesions are produced. The petioles, stems and tendrils are infected, and the lesions are brown and water-soaked.
3. The disease of the fruit mostly starts from the fruit stalk. At first, water-soaked spots appear on the fruit stalk. Later, the fruit stalk turns brown, and the fruit turns yellow, dehydrated and constricted.
4. When the field humidity is high, milky white turbid mucus is produced in the diseased part.
The etiology of bacterial blight of cucumber
1. Diseases caused by bacteria, pathogenic bacteria overwinter in the soil with infected seeds or with diseased stumps. In the next spring, when the conditions are suitable, the pathogenic bacteria spread to the host crops through rainwater splashing, insects, agricultural operations, etc., and invade and damage through natural orifices such as water holes in the leaf margins.
2. The pathogen preferslow temperature and high humidity. The optimum temperature for the disease is 8-20°C and the relative humidity is above 95%. Usually, the disease occurs during the low temperature period in early spring in the protected area. When the greenhouse temperature exceeds 25°C, the disease will be inhibited.
3. After the germinated seeds germinate, they will directly invade the cotyledons, causing the seedlings to get sick. The saturated humidity time in the shed at night is more than 7 hours, and the longer the leaf condensation time is, the more water-soaked lesions appear.
4. The cucumber leaves spit water, which will provide favorable conditions for the invasion and spread of pathogens.
Control methods of cucumber bacterial blight
1. For the treatment of cucumber seeds, soak the seeds in warm soup at 50°C for 30 minutes, remove them to dry, and then promote germination and sowing.
2. Protect the cultivation shed, clean the ditch in time to prevent water accumulation after rain, watering and fertilizing should be in the morning on a sunny day, and the shed should be opened in time for ventilation and humidity reduction.
3. Remove diseased and old leaves in time during the peak disease period, clean the garden after harvest, remove the diseased body, and take it out of the field for centralized destruction, dig the soil deeply, and accelerate the decay and decomposition of the diseased body.
