Symptoms

• Leaf spots first appear as small purple spots which enlarge. As the spots get older, they develop purple margins with brown centers.
• Fruit spots are one-fourth inch in diameter, black, and slightly depressed. They sometimes coalesce to cover a large portion of the fruit surface.
• Lesions also occur on twigs and are the overwintering inoculum. In the spring, twig lesions produce spores which are washed by rainfall to leaves.
• After infection there is a period of one week before symptoms are observed. Secondary infection can occur during the spring and summer when the temperature is near 75 degrees F. and surface moisture is on the leaves.

Management:

• Fungicides should be applied at full leaf development and continued at two week intervals for four sprays.