Bean Pod Mottle – Bean pod mottle virus (BPMV)

Background Information
  • Bean pod mottle is a common disease in the Midwest. Yield losses can be insignificant to major. This virus can interact with soybean mosaic virus to create severe symptoms.
Disease Agent
  • Bean pod mottle virus (BPMV) is transmitted by leaf-feeding beetles such as the bean leaf beetle. Seed transmission rates are very low. Host range includes common bean, some clovers, and perennial weeds.
Symptoms
  • Green to yellow mottling can be observed on young leaves.
  • Leaves may become distorted in severe cases.
  • Symptoms are reduced at high temperatures or after pod set.
  • Pod formation may be reduced when plants are also under moisture stress.
  • BPMV may be associated with green stem syndrome, in which plants retain green stems, and sometimes leaves, after pods and most nearby plants have matured.
Time of Occurence
  • All seasons
Conditions Favoring Disease
  • Presence of bean leaf beetles that transmit the virus when feeding
  • Cool temperatures
  • Infection that occurs early in the season
  • Note: Virus transmission may be reduced following severe winters that result in poor survival of beetles.
Disease Managment
  • Effective management tactics are not known.
  • Resistant varieties have not been developed.
  • The value of insecticides for controlling bean leaf beetle transmission of the virus is uncertain.