Persistence And Transmission. Anthracnose overwinters inside bean seed and in infected bean debris left in the field after harvest. The fungus can survive in seed as long as the seed remains viable, and for more than 2 years in old bean debris under field conditions. The fungus is spread by wind, rain, animals, workers, and farm implements. 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.