Sporulation by leafspot fungi

Both early and late leafspot are spread by spores of these fungi. These spores are needle like in appearance and are produced in microscopic tree-like clusters on the surface of spots. The spores are easily detached from these clusters by wind, rain or brushing against another object such as a leaf or farm implement. Once detached, the spore can cause a new infection of leafspot if it comes in contact with green peanut tissues. Periods of high humidity (above 95 percent) and temperature (above 80° F) favor infection and disease development. Leafspots generally become visible about 10 to 14 days after infection if weather conditions favor disease development.