VIEW ARTICLE

Incidence and Source of Inoculum of Peanut Mottle Virus and Its Effect on Peanut. O. R. Paguio, Department of Plant Pathology and Plant Genetics, University of Georgia, Athens 30602; C. W. Kuhn, Department of Plant Pathology and Plant Genetics, University of Georgia, Athens 30602. Phytopathology 64:60-64. Accepted for publication 20 June 1973. DOI: 10.1094/Phyto-64-60.

Peanut mottle virus (PMV) causes a major disease of peanuts (Arachis hypogaea) in Georgia. A mild mottle strain of PMV was predominant in commercial fields, but the necrosis and chlorotic line pattern strains were found infrequently. The source of primary inoculum appeared to be infected seed. PMV was transmitted through the seed of six peanut cultivars, obtained from a commercial source, at a rate of about 0.3%. We could not isolate PMV from weeds, trees, shrubs, or vines in or near peanut fields with PMV. Furthermore, the initial influence of an artificially inoculated plant did not extend more than 2 m, and the early-season spread within plots resulted in a greater number of adjacent (paired) infected plants than expected had the inoculum source been outside the plot. In test plots, 75-90% and 24-44% of the plants became naturally infected in 1971 and 1972, respectively. Yield losses of 20-25% for infected plants were similar and consistent in fields in 1971 and 1972. An early infection (June) caused a greater yield loss than a late one (August), but time of infection had no effect on the rate of seed transmission. PMV-infected plants produced more small seed than healthy plants, and the smallest seed had a PMV transmission rate of 3.7% as compared to 0 to 0.9% for larger seed.