Natural Infection, Disease Reactions, and Epidemiological Implications of Peanut Mottle Virus in Cowpea. J. W. Demski, Associate Professor, Department of Plant Pathology, Georgia Station, Experiment 30212. A. T. Alexander, Agricultural Research Assistant II, Department of Plant Pathology, Georgia Station, Experiment 30212, and Marcia A. Stefani, Former Graduate Student, and C. W. Kuhn, Professor, Department of Plant Pathology, University of Georgia, Athens 30602. Plant Dis. 67:267-269. Accepted for publication 20 July 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-267.

A mild strain of peanut mottle virus (PMV) was found in cowpea fields in Georgia in 1980 and 1981 but only when peanut fields were nearby. Infected cowpeas were either symptomless or showed a mild mottle, and plant growth and yield were not affected significantly by the virus in greenhouse studies. Ten of 24 Vigna entries were resistant to PMV. Aphis craccivora transmitted PMV to and from cowpeas and from cowpeas to peanuts. A low frequency of seed transmission was detected in one cowpea plant introduction. Field tests demonstrated natural transmission to and from cowpeas, from cowpeas to peanuts, and from peanuts to cowpeas. The necrosis strain of PMV caused a more severe disease in cowpea than the mild strain, and a mixed infection of PMV and cucumber mosaic virus caused a synergistic disease reaction in cowpea.