Virus Complex in Soybeans
Virus Complex
Symptoms
Plants infected early in the season by a virus are stunted. Leaves are stunted, misshapen, puckered and
Bean Pod Mottle Virus foliar symptoms (severe strain)
University of Kentucky Dept. Plant Pathology
occasionally with dark green areas along the veins. A yellow mottling in the form of spots may develop on young leaves of infected plants. Later in the season, symptoms may include a browning of yellow spots and a brown discoloration of the veins. When more than one virus is present, plants may become severely stunted and deformed with puckered leaves.
Cause
Temperatures between 65 and 78 degrees F are favorable for the expression of virus symptoms. Higher temperatures may mask symptoms. Aphids and bean leaf beetles are carriers of soybean viruses. Some viruses such as soybean mosaic virus are transmitted through the seeds.
IPM Techniques
- Fields should be checked every two weeks from vegetative stage until pod fill.
- At each scouting site, examine two rows of plants ten feet in length .
- The number of sites you will need to check in each field is based on the field size.
- To determine the number of scouting sites see the field size and number of locations chart.
- At each site you will need to note a rating of 0 to 3 based on the following scale:
0 = no plants showing virus symptoms;
1 = an occasional plant showing stunting, crinkling of leaves and/or leaf yellowing with brown veins;
2 = 2 -20% of plants affected as described in rating 1;
3 = greater than 20% of plants have rating 1 symptoms.
- Plant high-quality, disease-free seed or certified seed.
References and Additional Information
- IPM-3 Kentucky IPM Manual for Soybeans
- PPA-10b Kentucky Plant Disease Management Guide for Soybean by D.E. Hershman, Extension Plant Pathology, University of Kentucky
- Compendium of Soybean Diseases, J.B. Sinclair and P. A. Backman (The American Phytopathological Society Press)