A leaf disease which attacks members of the prunus family. This fungus destroys young leaves. New leaves will develop, however, their growth reduces established food reserves, weakens the tree, and may reduce yield. Defoliation by peach leaf curl in successive seasons may kill the tree. Infected leaves, which begin appearing in mid-May, are easily distinguished from healthy leaves in that they are curled, puckered and thicker than normal. Deformed areas are red to yellow at first and then turn brown. Eventually the infected leaves fall from the tree. Spray treatments recommended.