Fruit Yield, Disease Incidence, and Root Colonization of Hybrid Muskmelons Resistant to Fusarium Wilt. T. R. Gordon, Department of Plant Pathology, University of California, Berkeley 94720. D. J. Jacobson, D. M. May, K. B. Tyler and F. W. Zink. Department of Plant Pathology, University of California, Berkeley 94720; Fresno County Farm Advisors Office, Fresno, CA 93702; and Department of Vegetable Crops, University of California, Davis 95616. Plant Dis. 74:778-781. Accepted for publication 18 April 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0778.

Eight F₁ hybrid muskmelons, bred for resistance to race 2 of Fusarium oxysporum f. sp. melonis, and an open-pollinated cultivar susceptible to Fusarium wilt were grown in 1987 in a commercial muskmelon field naturally infested with F. o. f. sp. melonis race 2 and in a field where the pathogen was absent. In 1988, nine disease-resistant hybrids and a susceptible cultivar were evaluated in trials at both locations. In both years, a high incidence of Fusarium wilt was observed on the susceptible cultivar in the infested field. Either no disease or very low levels were recorded for the wilt-resistant entries grown in the naturally infested soil. Resistant entries also yielded more fruit when grown in infested soil than the susceptible cultivar. Many of the hybrids also produced superior yields in the absence of the disease. F. o. f. sp. melonis colonized seedling roots of susceptible and resistant cultivars to the same extent but was recovered significantly more often from roots of the susceptible cultivar when mature plants were sampled.