Solarizing Soil Planted with Cherry Tomatoes vs. Solarizing Fallow Ground for Control of Verticillium Wilt. D. P. Morgan, Department of Plant Pathology, University of California, Berkeley 94720. J. A. Liebman, L. Epstein, and M. J. Jimenez. Department of Plant Pathology, University of California, Berkeley 94720, and University of California Cooperative Extension, Tulare County Civic Center, Visalia 93291-4584. Plant Dis. 75:148-151. Accepted for publication 16 July 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0148.

Soil solarization reduces inoculum of Verticillium dahliae in the San Joaquin Valley, California, but is in limited use, partly because the treatment must be applied during the summer, which interferes with normal production schedules. We compared the efficacy of polyethylene mulches applied to fallow ground with mulches applied to ground planted with cherry tomatoes (Lycopersicon esculentum). Mulches applied on tomato plots for the entire growing season (17 April–1 September) controlled Verticillium wilt as effectively as mulches on fallow soil. Compared with nonsolarization, full-season solarization significantly reduced soil inoculum density of V. dahliae, reduced the percentage of infected plants the year the mulches were applied and the subsequent year on cherry tomatoes and eggplants (Solanum melongena), and increased yields of tomatoes and eggplants the year after the mulch application. Although mulches applied midseason (25 June) to tomatoes were relatively ineffective in controlling Verticillium wilt, mulches applied late in the season (30 July) to fallow plots were somewhat effective in controlling Verticillium wilt. Because soil solarization did not unduly interfere with normal agronomic practices, application of polyethylene mulches early in the season may provide a useful means of controlling Verticillium wilt in cherry tomatoes.