VIEW ARTICLE

Disease Control and Pest Management

Influence of Soil Solarization at Moderate Temperatures on Potato Genotypes with Differing Resistance to Verticillium dahliae. J. R. Davis, Professor, Department of Plant, Soil and Entomological Sciences, University of Idaho Research & Extension Center, Aberdeen, ID 83210; L. H. Sorensen, research associate, Department of Plant, Soil and Entomological Sciences, University of Idaho Research & Extension Center, Aberdeen, ID 83210. Phytopathology 76:1021-1026. Accepted for publication 20 January 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/Phyto-76-1021.

A 3-yr study involving solar heating of the soil (solarization) with polyethylene mulching demonstrated disease suppression and significant improvements in yield and quality of potato. This occurred at maximum air temperatures with a mean of 26-33 C on a weekly basis and with elevations of soil temperatures that were believed to be marginal for inoculum reduction (mean of 26 C compared with 41 C at 15 cm for nonmulched and mulched sites, respectively). Common scab (Streptomyces scabies) was suppressed, belowground stem lesions were reduced (associated with Rhizoctonia solani AG-3 and Colletotrichum atramentarium) and Verticillium wilt (Verticillium dahliae) was effectively controlled. Total yields of cultivar Russet Burbank were increased by 46%, and the amount of U.S. #1 tubers was improved by 118%. A potato clone (A68113-4) with a high degree of resistance to V. dahliae also responded positively to the solarization treatment (18% increase of total yield and 25% increase of U.S. #1 potatoes). Lasting effects of suppression of V. dahliae were evident for 2 yr after treatment.