Todays’s disease photo comes courtesy of Gerald Roberts in Lafayette Parish. This is peach scab caused by the fungus Cladosporium carpophilum. The pathogen infects twigs and leaves as well as the fruit. Spots on the fruit are generally small (usually less than 1/8 inch in diameter), dark olive-green in color and are usually surrounded by a green to yellow halo. This disease is controlled primarily by the use of protectant fungicide sprays, such as captan, beginning shortly after petal fall and continuing throughout the summer.
Donald M. Ferrin, Ph.D., Louisiana State University Agricultural Center, Baton Rouge, LA