What is the cause of cucumber bacterial blight?

Cucumber is widely cultivated in China, and many areas are cultivated in greenhouses or plastic greenhouses; now it is widely cultivated in temperate and tropical regions. Cucumber is one of the main vegetables in summer all over China, in addition to stem and rattan medicinal, can reduce inflammation, expectorant, antispasmodic. In the specific planting process, it is easy to produce cucumber bacterial blight, what is the cause of the disease? What are the symptoms? How to prevent and cure it? Let's take a look.

First, what is the cause of cucumber bacterial blight?

Marginal pathogenic variety of Pseudomonas aeruginosa, belonging to bacteria. The pathogen overwintered on the seed or in the soil with the disease residue and became the source of infection at the beginning of the next year. The pathogen invades from the natural orifices such as water holes on the leaf margin, and spreads and repeats infection by wind and rain, field operations and so on. Mainly affected by the humidity change and foliar condensation caused by rainfall, the relative humidity of the greenhouse is high in spring and summer in northern China, especially at night, with the decrease of temperature, the humidity continues to rise to 70% or saturated, and the disease is serious for as long as 7-8 hours.

Symptoms of bacterial edge blight of cucumber

The bacterial edge blight of cucumber first occurred in the leaves, which initially produced water-stained spots near the water pores, then expanded into light brown irregular spots, and expanded along the leaf veins to the leaves in a V-shaped shape, which seemed to be scalded by water. The disease spots on petiole and stem tendrils are also brown in the shape of water stains. Melon strips begin to soften from the tip. When the humidity is high, the disease part overflows a large amount of milky white bacterial pus, and when it is serious, the melon strips will soften.

3. Treatment of bacterial edge blight of cucumber

1. Seed disinfection

Sterilization with 70 ℃ constant temperature and dry heat for 72 hours. Soak the seeds in 50 ℃ warm water for 20 minutes, remove them and dry them, then sprout and sow them. Soak the seeds with calcium hypochlorite 300x solution for 30min, or 40% formalin 150x solution for 1.5h, or 1 million units of streptomycin sulfate 500x solution for 2 hours, rinse thoroughly and accelerate germination and sow.

2. Agricultural prevention and control

It is necessary to strengthen the disease-free production of cucumber seed production base, select disease-free fields and leave seeds without disease. Cultivate disease-free strong seedlings and raise seedlings in disease-free soil seedling bed. Pay attention to timely windproof, reduce the temperature of the shed, and increase the light. Increase the application of rotten organic fertilizer, control irrigation after the disease and promote root development. Popularize the cultivation techniques of high ridge, plastic film mulching and dark watering. Pay attention to proper crop rotation, remove the sick and disabled bodies, and turn the soil in time.

In the protected cultivation shed, clean the ditch in time to prevent stagnant water after rain, watering and fertilization should be in the sunny morning, and open the shed in time to ventilate and reduce humidity. Promote interannual rotation with non-Cucurbitaceae crops to reduce the source of pathogens in the field.

3. Chemical control

Cucumber bacterial edge blight at the initial stage of the disease with 72% Kelou wettable powder 600 times 750 times, foliar spray, once every 7 days, a total of 4 times 6 times. Commonly used pesticides include agricultural streptomycin 250mg/kg solution, neophytomycin 200mg/kg solution, 14% ammonia copper solution 300x liquid, 3% Kejiankang wettable powder 8001000 times liquid, 50% nail cream copper wettable powder 600x liquid. The protected area is sprayed with 10% ethyl dust or 5% chlorothalonil or 10% lipid copper dust 15kg each hectare.