Sclerotinia sclerotiorum commonly known as "white stalk", "hemp stalk", "mycosis", etc., is one of the major diseases affecting the growth of rapeseed. The prevention and treatment of rapeseed sclerotinia should be based on prevention. The main prevention and control measures are as follows.
1. To prevent seed borne bacteria from screening, wind selection, seed dressing and other methods to eliminate sclerotia and kill epidermis, seed disease-free seeds. Before sowing, 0.5 ~ 0.75 g salt or 0.5 ~ 1 kg ammonium sulfate can be used, and 5 kg of water can be selected for seeding. The floating grains and sclerotia can be removed, washed with clean water and then sowed.
2. Turning crops and droughts to avoid continuous cropping of seedbeds and heavy crops. Rapeseed should avoid continuous cropping as much as possible, and it is best to use paddy crop rotation to reduce field sclerotia. After the rapeseed was harvested, the sicknesses in the fields, roadsides, and threshing yards were completely removed and burned.
3. Strengthen field management, improve the structure of the group, pay attention to trenches, and stay rainy. Deep plowing in autumn, cultivating soil in spring cultivating 1 or 2 times, can destroy, submerge buried sub-capsule plate. Timely weeding reduces the shade of the field. Reapply basal fertilizer, increase application of organic fertilizer, phosphorus and potassium, and boron fertilizer, and appropriately apply nitrogen fertilizer. Apply fertilizer early to avoid overdose of nitrogen fertilizer during flowering. Do a good job of cultivating soil in the cultivator, remove the disease, yellow and old leaves in time, and bring it out of the field immediately to reduce the risk of spread of germs. In areas with high soil fertility, the planting density of rapeseeds should be appropriately reduced to improve the ventilation and light transmission conditions.
4. The timely control of rapeseed rape is the most susceptible period, and it is also a critical period for the prevention and treatment of rape sclerotia. General spraying 2 times, it is very important to use the first drug in the early flowering period, use the 2nd drug after 7-10 days, and continue to use the 3rd drug in case of consecutive rainy days after 2 drugs. In order to ensure the prevention of disease, one should adhere to the amount of 50-60 kilograms of water when it is used; the other is to insist on spraying coarse fog, spray from the flower to the base stem everywhere, so that the plants form a protective layer on the surface. When spray spraying, ensure that the liquid sprays all parts of the plant under the premise of spraying the lower stems and leaves of the plant. Commonly used pharmaceuticals: 40% pentachloronitrobenzene WP active ingredient 2625 g/ha, watered 150-300 kg, in the early stage of the disease, mixed with soil near the root of the applicator; 70% thiophanate-methyl WP active ingredient 750- 937.5 g/hectare, watered 600-750 kg, sprayed once every 7-10 days, sprayed twice in total; 50% Ethylenic Sclerotium wettable powder active ingredient 562.5-750 g/ha, watered 750-1125 kg At the beginning of onset, spraying once every 7 to 10 days for a total of 3 to 4 times; 40% carbendazim suspension or 25 to 50% of wettable powder active ingredient 562.5 to 937.5 g/ha, and watering 750 to 1125 kg , Spraying at full flowering and final flowering time; 50% active ingredient of phonic acid WP: 500-750g/ha, watering 750～1125kg, spraying once at full bloom and final flowering; 50% speed Keling WP, active ingredient 225 ~ 450 g / ha, watered 750 ~ 1125 kg, sprayed at full flowering and final flowering time; or 50% prochloraz manganese salt, 40 g watered 20 kg spray. At the flowering stage of rapeseed, the yellow leaves, old leaves, and diseased leaves of the whole plant were removed and the removed leaves were taken out of the field.
It should be noted that S. sclerotiorum has generally been resistant to carbendazim, using sclerotia net, procymidone, and 100 g, valerian (Beta moldew), and the enemy off (c) Cyclozole) single agent and its compounding agent are effective, but also should be used early rape, disease resistance, high yield and quality of rapeseed varieties.