Pepper anthracnose caused by Colletotrichum sp. In older lesions, black structures (acervuli) may be observed. Warm, moist weather during fruit development, poorly drained soil and plant stress caused by improper fertilization practices favor disease development. Blossom-end rot is a non-parasitic disease of peppers caused by calcium deficiency during fruit development. Pythium fruit rot on pepper. Pythium is a soil-borne pathogen often referred to as a "water-mold." Elevated soil moisture levels and high temperatures favor disease development. Recycled water is a common source of inoculum and means of pathogen spread. Bacterial spot caused by Xanthomonas campestris pv. vesicatoria. Initial symptoms appear on the lower surfaces of leaves as small, irregular water-soaked areas. These spots enlarge as disease progresses and become purplish gray with black centers. Image courtesy of Clemson University. Phytophthora capsici, the cause of Phytophthora blight of peppers, attacks both the roots and aboveground parts of pepper plants. Once the pathogen establishes the foliar phase, disease spreads quickly.

Pepper anthracnose. Circular or angular sunken lesions may develop on immature fruit of any size, particularly during ripening. Lesions can develop on stems and foliage as well. Sunscald occurs commonly on peppers exposed to intense sunlight. The exposed tissues appear sunken and white with a dry papery feel. These lesions are often colonized by opportunistic fungi that may further contribute to rotting of the fruit. Southern blight, caused by the soilborne fungus Sclerotium rolfsii, results in the wilting and death of affected pepper plants. Mycelium of Sclerotium rolfsii is often visible at the base of plants with southern blight. Phytophthora blight affects all parts of the pepper plant, here seen causing stem lesions and fruit rot. Note the profuse sporulation of the pathogen on affected tissues. The pathogen is spread rapidly by rain-splashing and the wind.