Guard against the occurrence of rice sheath blight under high temperature and humidity

Sheath blight, also known as sheath blight, rice sheath blight has a great impact on its growth and development, not only weakening the absorption capacity of roots, but also affecting leaf photosynthesis, resulting in an increase in empty chaff grains, a decrease in 1000-grain weight and a decrease in yield. Therefore, attention should be paid to the prevention and control of sheath blight in production. The main symptoms, occurrence characteristics and control methods of this disease are introduced below for reference.

The main symptoms of rice leaf sheath disease are dark green water-immersed small spots with blurred edges near the surface of the water, then enlarged in the shape of oval or moire, grayish green or grayish brown in the middle, yellowish or grayish white in the middle when the humidity is low, transparent tissue destruction in the middle, dark brown on the edge, and fusion of several disease spots to form large disease spots in severe cases, showing irregular moire spots, the edges turn yellow, and when the disease occurs quickly, the disease spots are dirty green. The leaves rot quickly. Stem damage, the first dark green, and then turn gray-brown, often can not heading, heading of more blighted grain. When the humidity is high, the disease grows out of white reticular hyphae, and then aggregates into white mycelia to form sclerotia. The sclerotia is dark brown, shaped like mouse dung and easy to fall off. It will become the source of infection in the coming year when it is left in the field.