The Occurrence of Fusarium oxysporum on Phoenix canariensis, a Potential Danger to Date Production in California. Tolbert V. Feather, Former Graduate Student, Department of Plant Pathology, University of California, Riverside, 92521. Howard D. Ohr, Donald E. Munnecke, and John B. Carpenter. Cooperative Extension Specialist, Professor Emeritus, Department of Plant Pathology, University of California, Riverside, 92521, and USDA Retired Research Plant Pathologist, USDA Date and Citrus Experiment Station, Indio, CA. Plant Dis. 73:78-80. Accepted for publication 31 August 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0078.

Fusarium oxysporum, in association with Gliocladium vermoeseni, causes a disease complex called wilt and dieback on Phoenix canariensis (Canary Island palm) in California. Both fungi were pathogenic, by stem injection, singly and in combination to P. dactylifera (date palm). F. oxysporum also infected date palm seedlings through roots. The symptoms of wilt and dieback are similar to those of bayoud of P. dactylifera, an important disease found in North Africa, and caused by F. oxysporum f. sp. albedinis. Our work showed that the pathogens, especially F. oxysporum, were potential pathogens of P. dactylifera, and consequently the California Department of Food and Agriculture established a quarantine in an effort to prevent their being introduced into date-growing areas in California.