Fusarium wilt has become a problem in fields where pre-plant fumigants did not include methyl bromide and where fumigants were applied to beds through drip-lines rather than through flat fumigation of an entire field. The changes in pre-plant fumigation methods have resulted in incomplete treatment of the soil, which has allowed pathogens to build-up to damaging levels.
This includes a host-specific strain of Fusarium oxysporum, known as
F. oxysporum f. sp. fragariae. Fusarium oxysporum is commonly found in agricultural soils throughout California but most strains are not pathogenic. Those that are pathogenic cause disease on only a narrow range of hosts, usually a single crop. The strain we have found to be pathogenic on strawberry (1) might have been derived from local strains of F. oxysporum or could have been introduced from other strawberry production areas outside the U.S.
Presently we are evaluating the efficacy of alternative fumigants and non-chemical control measures. We are also testing cultivars and breeding lines for resistance to Fusarium wilt. Results to date show that the U.C. cultivars ‘Ventana’ and ‘San Andreas’ have a high level of resistance to the disease.
1. Koike S.T., Kirkpatrick S.C. and Gordon T.R. 2009. Fusarium wilt of strawberry caused by Fusarium oxysporum in California. Plant Disease 93:1077-1077.
2. Gordon, T.R. 2017. Fusarium wilt and the Fusarium wilt syndrome. Annual Review of Phytopathology 55: In press
3. Henry, P.M., Kirkpatrick, S.C., Islas, C.M., Pastrana, A.M., Yoshisato, J.A., Koike, S.T., Daugovish, O., and Gordon, T.R. 2017. The population of Fusarium oxysporum f. sp. fragariae, cause of Fusarium wilt of strawberry, in California. Plant Disease 101:550-556.
4. Gordon, T.R., Daugovish, O., Koike, S.T., Islas, C.M., Kirkpatrick, S.C., and Yoshisato, J.A. 2016. Options for management of Fusarium wilt of strawberry. International Journal of Fruit Science DOI:10.1080/15538362.2016.1219294.
5. Lloyd, M.G. and Gordon, T.R. 2016. Growing for the future: Collective action, land stewardship and soilborne pathogens in California strawberry production. California Agriculture 70:101-103.
6. Koike, S.T., Arias, R.S., Hogan, C.S., Martin, F.N., and Gordon, T.R. 2016. Status of Macrophomina phaseolina on Strawberry in California and Preliminary Characterization of the Pathogen. International Journal of Fruit Science DOI:10.1080/15538362.2016.1195313.
7. Koike, S.T., Gordon, T.R. 2015. Management of Fusarium wilt of strawberry. Crop Protection 73:67-72.