Fusarium Wilt (F. oxysporum f. sp. melonis Race 0) of Muskmelon in Texas. R. D. Martyn, Texas Agricultural Experiment Station, College Station 77843. L. W. Barnes, and J. Amador. Texas Agricultural Extension Service, College Station 77843, and Texas Agricultural Extension Service, Weslaco 78596. Plant Dis. 71:469. Accepted for publication 21 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0469D.
Fusarium wilt (Fusarium oxysporum Schlect. f. sp. melonis Leach &
Curr.) of muskmelon (Cucumis melo L. var. reticulatus Ser.) was
confirmed in Texas for the first time from the Lower Rio Grande Valley
in 1986. Random plants in commercial plantings of cv. Perlita showed
yellowing, stunting, wilting, vine death, and vascular discoloration.
Isolations consistently yielded F. oxysporum. Microconidia (106 / ml)
from monoconidial cultures of selected isolates were used to inoculate
2-wk-old seedlings ofthe susceptible cv. Explorer. A pathogenic isolate
from the initial test was selected and tested on four differentials-Charentais
T, Doublon, CM 17-187, and Perlita FR. The Texas isolate
was pathogenic only to Charentais T, causing 100% wilt. All other
differentials were 100% resistant to the Texas isolate. On the basis of
reaction of these four cultivars, the Texas isolate is designated F. O. f. sp.
melonis race 0 sensu Risser et al (1,2). Race 0 is a European race and has
been detected at only one other location in the United States
(California, unpublished). Texas produces 8,100 ha of muskmelon each
year, and Fusarium wilt may become a significant factor in production.