Airborne Dispersal of Bacteria in Tomato and Pepper Transplant Fields. T. B. McInnes, Graduate Research Assistant, Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793. R. D. Gitaitis, S. M. McCarter, C. A. Jaworski, and S. C. Phatak. Associate Professor, Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793; Professor, Department of Plant Pathology, University of Georgia, Athens 30602; Soil Scientist, USDA-ARS, Tifton, GA 31793; and Professor, Department of Horticulture, Coastal Plain Experiment Station, University of Georgia, Tifton 31793. Plant Dis. 72:575-579. Accepted for publication 12 January 1988. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/PD-72-0575.

Aerosols were sampled over commercial fields and experimental plots of tomato transplants in southern Georgia. Viable bacteria were detected during three sample periods, (0700–0900, 1130–1330, and 1530–1730 hours). The highest concentrations of bacteria were collected from 1530 to 1730 hours. Significantly fewer bacteria were collected after periods of rain or irrigation. In contrast, the practice of clipping plants to achieve plant uniformity increased the number of bacteria collected. However, this effect decreased with subsequent clipping (as transplant harvest approached). The number of bacteria collected also was higher when transplants were harvested. An increase in the number of airborne bacteria could result in the downwind dissemination to later plantings. A standard copper + mancozeb mixture applied on a weekly basis failed to control bacterial spot caused by Xanthomonas campestris pv. vesicatoria, or affect numbers of aerosolized bacteria above treated areas. Copper + mancozeb sprays prevented the apparent establishment of epiphytic populations of Pseudomonas syringae pv. syringae, but did not affect numbers of total aerosolized bacteria.

Keyword(s): bacterial speck, Capsicum annuum, Lycopersicon esculentum, Pseudomonas syringae pv. tomato.