Crop rotation and genetic resistance reduce risk of damage from Fusarium wilt in lettuce
Jeness C. Scott, UC Davis
Thomas Gordon, UC Davis
Sharon C. Kirkpatrick, UC Davis
Steven T. Koike, UC Cooperative Extension, Monterey County
Michael E. Matheron, University of Arizona
Oswaldo E. Ochoa, UC Davis
Maria J. Truco, UC Davis
Richard W. Michelmore, UC Davis
California Agriculture 66(1):20-24.
Fusarium wilt of lettuce, caused by the soilborne fungus Fusarium oxysporum f. sp. lactucae, affects all major lettuce production areas in California and Arizona. In trials at UC Davis, we found that lettuce cultivars differ significantly in susceptibility to the disease, with some leaf and romaine types highly resistant under all test conditions. For more susceptible cultivars, disease severity is strongly influenced by inoculum levels and ambient temperature. Management of Fusarium wilt requires an integrated approach that includes crop rotation to reduce soil inoculum levels and the use of resistant cultivars during the warmest planting windows.
J.C. Scott is Postdoctoral Researcher, Department of Plant Pathology, UC Davis; T.R. Gordon is Professor, Department of Plant Pathology, UC Davis; S.C. Kirkpatrick is Staff Research Associate, Department of Plant Pathology, UC Davis; S.T. Koike is Plant Pathology Farm Advisor, UC Cooperative Extension, Monterey County; M.E. Matheron is Extension Plant Pathologist and Professor, School of Plant Sciences, University of Arizona, Yuma; O.E. Ochoa is Senior Research Associate, Department of Plant Sciences, UC Davis; M.J. Truco is Project Scientist, Department of Plant Sciences, UC Davis; R.W. Michelmore is Professor, Department of Plant Sciences, UC Davis.
The authors acknowledge financial support from the California Leafy Greens Research Board and thank Tom Kominek, Pauline Sanders and Richard Webb for technical assistance.