Cool wet weather promotes disease development while the fungus ceases to be active during hot dry conditions. Seed produced under wet, humid conditions are most susceptible to infection. For this reason, it is best not to save seed from year to year in Alabama. Do not plant beans in the same field for at least three years. Fields should not be worked when plants are wet because fungal spores are easily spread from diseased to healthy plants under these conditions.
Scout fields weekly for symptoms of the disease.
A fungicide with the active ingredient chlorothalonil or maneb should be applied when the disease is first observed and reapplied weekly during the season. Use chemicals only according to the directions on the label. Follow all directions, precautions, and restrictions that are listed. For more information , contact your county Extension office. Look in your telephone directory under your county's name to find the number.