Occurrence and control of garlic blight

The main symptoms of garlic blight are harmful leaves, pale white to light yellow flooded spots in the middle or tip of the leaves at the initial stage of infection, the edges are light green, the disease spots expand rapidly, and the disease spots rot in 3-5 days when the whole leaf or the whole leaf droops and the humidity is high, causing the whole plant to die.

2. pathogens and transmission pathogens overwintered with mycelium and chlamydospores in the underground part of the diseased plant or in the soil. In the next spring, the diseased part produced sporangia and mobile spores, and mobile spores spread by wind, rain and irrigation water to carry out primary infection and re-infection.

III. Influence factors

1. It is easy to develop the disease with heavy precipitation, more foggy days and high temperature. Generally, the disease is more serious when the temperature is 25 ℃ ~ 32 ℃, the relative humidity is higher than 95%, and there are water droplets.

2. There are some differences in the degree of susceptibility among varieties and sowing date. It does serious harm if the sowing time is too late. Timely sowing according to local conditions is the key link.

3. In fertilizer and water management, the disease of applying organic fertilizer, phosphate fertilizer and potassium fertilizer is mild, but the disease is more serious in the land with excessive nitrogen fertilizer too early, and the disease of poor fertility is more serious under different conditions. Many times of watering, the field humidity is easy to occur, therefore, watering depends on soil moisture and weather changes.

4. The suitable planting density of densely planted garlic is 35000 plants per mu, and the higher the density is, the more serious the disease is, mainly due to excessive density, large field leaf surface coefficient, poor ventilation and light transmission of lower leaves and high field humidity, which is beneficial to the rapid propagation of pathogens.

IV. Comprehensive prevention and control measures

1. Disease-resistant varieties should be selected according to local or non-local conditions, such as "high foot", "Pugu" and so on.

2. Pay attention to drainage to prevent excessive humidity and reasonable watering.

3. Remove the diseased and disabled body in time after harvest and burn it in deep burial.

4. Advocate the application of more organic fertilizer, biological bacterial fertilizer, potash fertilizer and less nitrogen fertilizer to enhance disease resistance.

5. At the initial stage of the disease, 72% Kelou wettable powder 800 times, 72.2% Purek water agent 800 times, and Dasheng Mmuri 45 wettable powder 600 times. Spray once every 10 days and control twice.