The disease is most commonly spread by wind and rain. The lima bean variety Eastland is resistant to the disease. Use disease-free seed. Use crop rotation. Do not plant beans in the same field for at least 2 years.
Scout fields weekly for symptoms of the disease.
Initiate a spray program with a fungicide containing the active ingredients chlorothalonil or maneb when the disease is first observed. Continue on a 7 to 10 day schedule. Be aware that there is a long waiting period from the last application of the fungicide until harvesting can begin. Use chemicals only according to the directions on the label. Follow all directions, precautions, and restrictions that are listed.