Latest Technical Methods Tutorial for Soybean Viral Disease Prevention and Control
Soybean is what is called yellow bean in the south. Soybean is extremely prone to viral diseases, and there are many types, roughly a dozen or so viral diseases. Viral diseases are mainly spread by insects, and seeds can also carry viruses. Several viral diseases in the south are transmitted by aphids. Sometimes several viral diseases occur together. What do the symptoms look like, and how should they be treated? Let us study together.
1. Causes of the disease
There are three pathogens in total. One is Soybean mosaic virus, which causes mosaic symptoms; Cucumber mosaic virus causes stunting and ring patterns on seeds; Alfalfa mosaic virus causes yellow markings. These viruses can occur at the same time, producing mixed symptoms. These viruses mainly occur in the south. They rarely occur in the north.
2. Disease manifestations
When the disease occurs in spring, the upper leaves become mottled, lose green color and turn yellow, with mosaic patterns, and the mesophyll has blister-like raised areas. They gradually begin to shrivel. After the leaves become deformed, the edges curl downward. The whole plant begins to become shorter, rarely sets pods, and even when it does set pods, they are deformed pods. After maturity, the seeds in the pods are very small, and brown spots may also appear inside.
3. Disease triggers
=Some high-yielding varieties are more susceptible to the disease than short, sturdy disease-resistant varieties. In regions or seasons with drought and little rain, there are many insects, especially large numbers of reproducing aphids, and the disease becomes very severe. Plants that are weak in growth due to lack of nutrients are easily infected.
4. Prevention and control methods
It is better to choose disease-resistant varieties such as Liaoxian No. 1. Plants kept for seed should be planted separately, and both seeds and soil should be carefully disinfected. Fertilizer should be applied at every stage to maintain soil nutrient supply. Pay attention to controlling aphids, and do not let aphids cause damage everywhere and spread the disease. Use a 500-fold spray of 20% Virus A, or spray with a 1000-fold solution of 1.5% Zhibingling emulsifiable concentrate. For aphids, spray with a 500-fold solution of 10% imidacloprid.
The common viral diseases of soybean are the above three, mainly causing damage in the south. Aphids are the main transmission vector. It is essential to focus on controlling aphids in order to effectively control the disease. Viral disease control should use medication when the disease is mild.