• Worldwide distribution. On peanuts, and other plants belonging to the genus Arachis. Important diseases.
• There are two types: early and late, but difficult to tell these fungi apart on symptoms – there is need of a microscope.
• Reduction of yields of 50% are possible.
• Spots, first on older leaves, produce spores that spread in wind and rain; the fungi survive in crop debris.
• Cultural control: avoid planting near old crops; 1-year crop rotation; remove “volunteers”; check crop once a week; tolerant varieties; collect and burn trash after harvest.
• Chemical control: begin to spray as soon as spots are seen and no later than 30-35 days; use chlorothalonil (also effective against rust) at 10-14 days until 14 days before harvest. More often if rainfall high.

Peanut leaf spots, early and late leaf spots of peanuts (groundnuts)

Mycosphaerella arachidis (early leaf spot) and Mycosphaerella berkeleyi (late leaf spot). These are the names of the fungus that produce sexual spores. Where only asexual spores are present, the fungus is known as Passalora (Cercospora) arachidicola and Passalora (Cercosporidium) personatum, respectively.