What diseases can affect peppers?
Listed below are five diseases that most frequently occur on beans. Symptoms are described briefly. Colored pictures of disease symptoms can be seen in the publication "Identifying Diseases of Vegetables" available from the Penn State Agricultural Mailing Room, or from extension offices.
Bacterial Spot
Small dark spots develop on leaves and fruit. When young leaves are affected, leaves tear around the leaf spots as the leaves expand.
Phytophthora Blight
Affected plants wilt and severely wilted leaves and branches die. Roots frequently are rotted. Under severe disease pressure, where soil is wet, entire plants can die rapidly. Large rot areas can develop to affect at least half a fruit; when conditions are wet, a whitish gray mold can appear on affected areas of fruit.
Viruses
Symptoms vary depending on the virus or strain, the plant, time of year and environmental conditions. The range of symptoms may include leaf mottling, puckering or curling; stem and petiole streaking; rough, deformed or spotted fruit; stunted plants; and leaf, blossom and fruit drop.
Disease Control Program:
(1) When possible, plant varieties with resistance to diseases of concern. Many varieties are resistant to TMV, the most important virus spread by rubbing leaves. A few are resistant to PVY and/or TEV viruses which are spread by aphids and by rubbing leaves. A few are resistant to some strains of the bacterial spot pathogen which affects both leaves and fruit.
(2) Start with disease-free seed and transplants from reputable producers. Bacterial spot can be introduced with seed and transplants.
(3) Plant peppers where peppers and tomatoes have not been grown for the past few years. The bacterial spot and Phytophthora blight pathogens can survive in soil for several years.
(4) Plant peppers in garden locations free of shade from the sun. Bacterial spots are promoted when plant surfaces remain wet for long periods.
(5) Plant peppers in garden locations with good moisture drainage. Phytophthora blight can occur where soil remains wet for long periods.
(6) Do not work in plantings when leaves are wet. The bacterial spot pathogen becomes sticky when wet, and can be carried from plant to plant on hands, garden tools and clothing.
(7) Try to prevent aphid problems near and in the garden. Aphids pick up and carry some viruses; it takes only 1 minute for an aphid to put a virus into a plant.
Dr. Alan A. MacNab, Professor, Plant Pathology
Penn State College of Agricultural Sciences
211 Buckhout Lab, University Park, PA 16802
Loaded: June, 2003
Where trade names are used, no discrimination is intended
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Information provided is intended for consideration by the user, but is not
intended to be a recommendation. Production decisions should be based on
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