Diseases of pepper (
Alfalfa mosaic virus
Alfalfa mosaic virus is transmitted to peppers by several species of aphids. The virus has a wide host range and several different strains. It occurs commonly where pepper is planted near alfalfa or after alfalfa in rotation. Symptoms appear in leaves as white blotches in a mosaic pattern (photos 1 and 2). Early heavy infections in pepper may cause stunting and distorted fruit, but mild infections usually are not a problem.
Alfalfa may be symptomless much of the year but is an active reservoir of the virus. Alfalfa mosaic virus is easily transmitted from alfalfa to pepper by common aphids in alfalfa such as the pea aphid and the blue alfalfa aphid. The virus is commonly seed borne in alfalfa, but there is little information about its transmission in pepper seed. Applications of insecticides to control aphids on pepper will not prevent viral infection. The aphids will transmit the virus in such a short time, and it takes so few of them, that vector control is not efficacious. To prevent alfalfa mosaic virus in pepper, avoid planting pepper near alfalfa.
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February 20, 2013