Sclerotinia sclerotinia sclerotinia is a disease caused by the fungus Sclerotinia sclerotiorum, which is widely distributed worldwide, especially in the middle and lower reaches of the Yangtze River and the southeast coastal areas of China. The disease mainly affects the stems, leaves, flowers, shorn and seeds of rapeseed, resulting in yield loss and quality deterioration.
Cultivation factors: improper sowing time, poor seedling management, and unsuitable plant density may make rapeseed seedlings vary greatly and weaken their stress resistance, so that they are susceptible to infection by Sclerotinia sclerotinia sclerotiorum.
Meteorological factors: high temperature in winter, increased precipitation in spring, especially continuous rainy weather, are conducive to the overwintering and reproduction of Sclerotinia sclerotinia and increase the probability of disease occurrence and epidemic.
Improper use of nitrogen fertilizer: Excessive application of nitrogen fertilizer causes excessive plant growth and increased humidity in the field, which is conducive to the breeding of germs.
1) Agricultural prevention and control
Selection of disease-resistant varieties: planting rapeseed varieties with strong disease resistance (tolerance).
Ditch cleaning and moisture management: keep the field ditch system unblocked, reduce the groundwater level, reduce the damage damage, promote the transformation of seedlings, and enhance the stress resistance of plants.
Field management: In the full flowering period of rapeseed, remove the yellow leaves, old leaves and diseased leaves in the middle and lower parts of the plant, and take them out of the field for treatment.
2) Chemical control:
Appropriate period for prevention and control: the first spraying is carried out when the flowering rate of the main stem of rape reaches 80%, and the second spray is carried out at an interval of 7 days.
Control agent: 50% Pythium wettable powder, 40% sclerotia net wettable powder, or 255% iprodione suspension, etc.
Precautions: Ensure sufficient amount of medicine and water, spray evenly so that the whole rape plant spray up and down. In case of continuous rainy weather, you should seize the rainfall gap and take medication in time.
3) Environmental Regulation:
Control the amount of nitrogen fertilizer: avoid partial application of nitrogen fertilizer and mix fertilizer reasonably.
Adjust the sowing date appropriately: try to avoid the high incidence of diseases.
4) Biological control:
Use biological pesticides, such as Scutellum co., Bacillus, etc., to reduce the use of chemical pesticides and reduce environmental pollution.
Through the above comprehensive control measures, the incidence of Sclerotinia sclerotinia in rape can be effectively reduced, and the impact of the disease on the yield and quality of rapeseed can be reduced. At the same time, attention should be paid to the promotion of agricultural technology to improve farmers' understanding and application ability of the knowledge of sclerotinia sclerotinia prevention and control, so as to ensure the healthy development of the rapeseed industry.