How to control the blight of sugarbeet

Blight is the main disease affecting sugarbeet producing areas in China, also known as Blackfoot disease, quenching disease, seedling rot, is the general name of the main diseases of sugarbeet seedling stage. Rhizoctonia solani occurs to varying degrees in sugar beet producing areas, with a general incidence of 30%, 40%, and serious lack of seedlings and ridges. If the sugarbeet is not properly defended before sowing, it will lead to a reduction in sugar beet yield or even no harvest.

Beet

From the symptoms of sugarbeet disease, the seedlings from ununearthed seeds to 3 pairs of true leaf stage could be infected with blight, and the disease was the most serious in 1-2 pairs of true leaf stage. The main types are: soil rot type, main root rot type, standing withered type and quenching type. The general symptom is that the young root and leaf Hypocotyl of sugar beet produce water-immersed disease spot, the disease spot gradually turns brown to black, and the part of the long disease spot becomes thin and constricted. When the disease was mild, the sugar beet plant remained normal green. Due to the lesion only reached the sugarbeet seedling epidermis or primary cortex, has not yet reached the pith, the young root peeling, the seedling can return to normal, but easy to form gourd-shaped beet root. Sugar beets with forked or malformed roots are formed when the seedlings are rotting.

From the point of view of the disease conditions, the disease of aquatic fungi is closely related to soil moisture. The higher the humidity is, the more serious the disease is. Low temperature, serious disease, poor drainage of low-lying land, poor soil structure or heavy soil, soil hardening during sowing, extensive soil preparation before sowing, low seed quality, weak seed germination, soil pH too high or too low or barren, will aggravate the blight of sugar beet.

Beet

From the point of view of prevention and control, (1) agricultural control. Fine soil preparation requires loose soil, upper and lower fruit, removal of weed stubble, no bumpy, combined with fertilization, to meet the standards of deep, loose, flat, clean and fertilized. after the harvest of the previous crop, 25-30 cm in autumn is adopted, suppressed in winter and raked in early spring to prevent the loss of soil moisture. (2) seed treatment. Stress-resistant sugarbeet varieties such as Tianyan 303, 304 and 305 polyploid sugarbeet varieties were selected. (3) Pesticide control. Crushing the seed ball 2-3 days before sowing can save seeds and improve the germination rate of sugarbeet. In order to control the blight, 0.25 kg of thiram can be used to mix 50 kg of beet seeds with water, or Baomiaoling can be used. A small bag of Baomiaoling can mix 50 kg of seeds. (4) reasonable rotation. Practice crop rotation for more than 5-8 years, and avoid continuous cropping. (5) increase phosphate fertilizer. The application of 50 kg phosphate fertilizer per mu of sugarbeet can promote the growth of seedlings and improve the ability of disease resistance.