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There are a number of important disease problems that can affect both the shade value and the nut crop of pecan trees.  Pecan scab, caused by the fungus Venturia effusa (syn. Cladosporium caryigenum), is the most widespread and destructive disease of pecans. Even though scab can occur on leaves and twigs, the main damage is caused by infection of the nut shuck. Powdery mildew, caused by the fungus Erysiphe penicillata (syn. Microsphaeria alni), can be an occasional problem.  This fungus forms a white, dusty covering on the surface of developing nuts and shoots of the tree.  Downy spot is caused by the fungus Mycosphaerella caryigena. This fungus only attacks the leaves and is usually seen in late June or early July in Arkansas.

• Fruits and Nuts
  • Pecan