Ascochyta Blight. This disease is common when cool. Ascochyta leaf blight comes on quickly, causing large brown or bleached patches in lawns when the weather is quickly alternating between very wet and very dry,.
Symptoms, biology and management of ascochyta blight ( phoma exigua) of french beans: Ascochyta leaf blight (ned tisserat, colorado state university, bugwood.org) ascochyta leaf blight symptom (iowa state university extension)