Black Rot (fungus - Physalospora obtusa): Black rot is a firm, textured rot. The spot is light brown and darkens with age. As it enlarges, it is marked with concentric dark bands. The lesion is convex in shape, yet in very advanced stages becomes somewhat depressed. On the leaf the lesion is a purple speck that enlarges and eventually has a center which is brown or yellowish-brown. The fungus infects foliage at petal fall. Fruit infection is not normally evident until midsummer. The disease is favored by temperatures of 80 degrees F and light rain. Although fungicides help, sanitation is the best means of reducing this disease.

 

---