Several products containing diazinon or malathion are registered for aphid control on beans. As with all pesticides, make sure the label specifies your intended uses, and follow the directions carefully. Diseases Little is known about diseases affecting fava beans under California conditions due to the limited acreage in production. One disease identified in the northern San Joaquin Valley area is Chocolate Spot, Botrytisfabae. This fungus disease causes brown spotting on leaves and pods and is favored under moist conditions.
Severe attacks can cause leaf and pod loss.
Several virus-like diseases and powdery mildew have been observed on fava beans, but were not positively identified as to the causal agents. Fava beans are a preferred host of black aphids and may serve as a bridging host for virus diseases that the aphid transmits to other leguminous species. Favism Favism is an inherited disorder of certain individuals, particularly of southern European origin. These people have an enzyme deficiency expressed when fava beans are eaten, especially raw or partially cooked. Symptoms commonly include acute toxic hepatitis and those similar to influenza.