Biological Implications of Drift from Sprayers in Tomato Fungicide Field Trials. J. P. Reed, Graduate Research Associate, Laboratory for Pest Control Application Technology, Ohio Agricultural Research and Development Center, Wooster 44691. F. R. Hall, and R. M. Riedel. Professor and Head, Laboratory for Pest Control Application Technology, Ohio Agricultural Research and Development Center, Wooster 44691; and Professor, Ohio State University, Columbus 43210. Plant Dis. 77:186-189. Accepted for publication 20 October 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0186.

Fungicide field trials on tomatoes were conducted in 1988 and 1989 to compare spray drift produced by three sprayers used to apply fungicides for control of fruit and foliar diseases. An air-assisted sprayer consistently provided greater coverage of tomato foliage and subsequent disease control than either a commercial or small-plot hydraulic sprayer. A significantly greater proportion of spray by the commercial hydraulic sprayer was prone to drift in 1988 and 1989. Comparison of the percentage of tomatoes with rot in adjacent downwind plots demonstrated that spray drift could be an interfering factor in tomato fungicide field trials.