Occurrence and control of spring soybean virus disease

Virus disease is the main disease of spring soybean, the yield is reduced by about 15% in the year of general disease and more than 50% in the year of reoccurrence.

The main results were as follows: 1 after the onset of symptomatic spring soybean, the upper leaves appeared yellowish and green mottled, the mesophyll showed bubbly protruding along the leaf veins, then the mottled wrinkles became more and more serious, the leaves were deformed, the mesophyll protruded, the leaf margin rolled down, the plant growth was obviously dwarfed, the number of pods decreased, and the pods were fine. the pod is flat, curved and other abnormal symptoms. After the disease spring soybean matured, the bean grain decreased obviously, and could cause light brown markings on the soybean grain.

(2) there are three original pathogens of spring soybean virus disease: ① soybean mosaic virus (SMV). Soybean mosaic symptoms are caused by SMV infection. ② cucumber mosaic virus (CMV), CMV caused soybean atrophy symptoms and soybean grain rims. ③ alfalfa mosaic virus (AMV), AMV causes mosaic symptoms in soybean leaves, which is characterized by distinct yellow markings. The three viruses that cause soybean virus disease often infect soybean at the same time, and the symptoms in the field are not single symptoms, but mixed symptoms.

3 influencing factors

3.1 there were significant differences in disease resistance of different soybean varieties to virus disease. Liaoxian 1 and Japanese dwarf early have strong disease resistance. Taiwan 75 introduced in the past few years has expanded planting area because of its good quality and high yield, but Taiwan 75 has poor disease resistance, easy to develop virus disease and serious disease.

3.2 Climatic factors, dry weather and little rain, on the one hand, have a negative impact on the growth of soybean and reduce disease resistance, on the other hand, it is beneficial to the growth and activity of aphids, and aphids are the main vector of soybean virus disease. Therefore, the weather is dry and less rain, especially from April to May, the incidence of soybean virus disease is serious.

3.3 cultivation and management factors to strengthen soybean fertilizer and water management, reasonable application of potassium fertilizer and phosphate fertilizer, timely irrigation and watering in dry weather, timely removal of weeds in the field and around, and cultivation of robust soybean plants can improve resistance to virus disease. Properly raising the sowing date of early spring soybean can reduce the occurrence of virus disease.

4 Prevention and treatment

4.1 select disease-resistant varieties, establish disease-free seed fields, and select brown spot-free and full bean seeds as seeds.

4.2 strengthen fertilizer and water management, cultivate healthy plants, and enhance disease resistance.

4.3 early control of aphids, prevention and control of aphids should be carried out from the seedling stage to prevent and reduce virus infection.

4.4 the use of chemicals to control spring soybean virus disease should start from the seedling stage, so as to improve the control effect. It can be combined with the prevention and treatment of aphids at seedling stage. The medicament can choose 20% virus A500 times solution or 1.5% Zhishanling EC 1000 times solution, or 5% Shiduqing 400 times solution, use it continuously for 2 times or 3 times, once every 10 days.