The Occurrence and Control of Wheat Spring Blight in Wheat

I. Occurrence and damage of wheat sheath blight

Wheat sheath blight is a fungal disease mainly transmitted by soil. With the increase of the level of production, the promotion of high-yield varieties and the management of large-scale and large-scale wheat fields have become increasingly serious.

Rhizoctonia solani has a wide host range, and in addition to infecting wheat, it can also infect corn, rice, millet, sorghum and other crops and grass weeds such as Setaria, Valerian officinalis, crabgrass, and barnyardgrass. The main source of infestation is sclerotia or mycelia, which live in winter and summer in the soil and the diseased body.

After sowing, the germinating seeds will germinate, the buds will become brown, and the buds will rot and die. The diseased planting rate will increase significantly after jointing and the condition of wheat booting at the heading stage will develop rapidly. The rate of diseased plants will reach a peak at the filling stage, and the lesions Expanded, interconnected into a typical moire-like spot, later invaded the stem to cause rotten stems, and even the formation of withered ears, less fertility, and grain thin.

Second, prevention and control technology

1. Agricultural control

Timely control of weeds can reduce the humidity in the field and improve the ventilation and light conditions in the field. The application of formula fertilization, top dressing during jointing stage, and nitrogen and potassium fertilizer in combination with topdressing can effectively improve the disease resistance of plants and avoid partial nitrogen fertilizer to avoid causing wheat seedlings. Late marriage is greedy, and induce harm to the disease.

2. Chemical control

The control of wheat sheath blight should be focused on seed treatment, and severe disease fields should be supplemented with early spring fields to infuse drugs effectively to control the disease.

(1) Spring prevention and treatment: According to the condition of the investigation, early spraying will be used for prevention. If the disease rate of the field is 15% to 20%, 12.5% ​​of the licorice can be applied to the wettable powder 20-30 per acre. Grams or 15% triadimefon wettable powder 50-100 grams or 5% Jinggangmycin water 150-200 ml, optionally adding 50-75 kilograms of water to spray the lower part of wheat plants, every 7-10 days Spray once and spray 2-3 times. At the booting stage, 15% triadimefon wettable powder 50-100 grams per mu is sprayed with 60 kg of water per acre. If the simultaneous occurrence of pests can be combined with the control of wheat stubble, wheat spider arachnid and other pesticides, it can achieve the purpose of cure.

(2) If sheath blight occurs early and heavy in the fall seedling stage, and there is more rainfall in spring and the disease may occur, the control index should be strictly controlled and the prevention and treatment time should be appropriately advanced.