Detailed profiles of common plant diseases, pests, nutrient deficiencies and environmental problems.
Aspergillus flavus is a soil- and residue-associated fungus that can colonize developing corn kernels, peanuts, cottonseed and tree nuts, particularly when crops experience heat,…
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Ascochyta pisi causes a fungal leaf and pod spot disease of garden and field pea in the United States. Symptoms include tan to brown,…
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Armillaria root rot is a persistent soilborne fungal disease caused here by Armillaria mellea, commonly called honey fungus or oak root fungus. It attacks…
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Apple stem grooving virus is a graft-transmitted viral disease of apple and other woody fruit crops. Most commercial apple cultivars remain symptomless, but susceptible…
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Apple mosaic virus is a graft- and root-graft-associated viral disease of apple. Infected leaves develop irregular cream, yellow or white mottling, often along veins;…
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Apple chlorotic leaf spot virus is a graft-transmitted virus of apple and other woody plants in the rose family. Many commercial apple cultivars carry…
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Sycamore anthracnose is a fungal disease of sycamores and plane trees caused by Apiognomonia veneta. It is most damaging during cool, wet springs, when…
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Oak anthracnose is a cool, wet-weather fungal disease associated with Apiognomonia errabunda, especially on oak leaves, shoots, and twigs. Early infections may produce vein-associated…
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Aphanomyces root rot is a persistent, soilborne disease of peas, alfalfa and several other legumes caused by the water mold Aphanomyces euteiches. It is…
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Early blight is a widespread fungal disease of tomato, potato and other nightshades caused by Alternaria solani. It usually begins on older, lower leaves…
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Purple blotch is a fungal leaf disease of onions and related Allium crops caused by Alternaria porri. It begins as small, water-soaked or whitish…
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Alternaria dauci causes carrot Alternaria leaf blight, a fungal disease that usually begins as small brown to black spots with yellow margins on older…
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