Distribution of Races of Fusarium oxysporum f. sp. vasinfectum Within the United States. A. J. Kappelman, Jr., Research Plant Pathologist, USDA, ARS, and Adjunct Associate Professor, Department of Agronomy and Soils, Alabama Agricultural Experiment Station, Auburn University, 36849. Plant Dis. 67:1229-1231. Accepted for publication 13 May 1983. 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, 1983. DOI: 10.1094/PD-67-1229.

Isolations of Fusarium oxysporum f. sp. vasinfectum inciting vascular wilt of cotton (Gossypium hirsutum L.) were collected from across the cotton belt in the United States. Fifty-three of these isolates that induced symptoms on artificially inoculated, greenhouse-grown cotton were also evaluated on two tobacco (Nicotiana tabacum L.) differentials. Eleven of the 53 isolates caused wilting on both Gold Dollar and Burley 5 tobacco, whereas 42 caused wilting only on Burley 5. Thus, these 11 isolates would be classified as race 2 of the fungus. Because the 11 isolates that caused wilting on both tobacco cultivars were derived from a wide geographical area (California, Alabama, South Carolina, and North Carolina), race 2 of the fungus is more prevalent and widespread than originally reported.