Fusarium wilt of cotton: Management strategies

• Fusarium wilt of cotton, caused by Fusarium oxysporum f. sp. vasinfectum (FOV), is an inoculum dependent disease caused by six races and many genotypes of FOV.
• FOV can persist in soil as chlamydospores and on the roots of resistant cultivars and other plants.
• The most successful strategy for FOV management is the use of resistant cultivars.

Cotton is a globally important crop used for both its natural fiber and seed. Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. vasinfectum, is a major disease of cotton capable of causing significant economic loss. The fungus persists in soil as chlamydospores and in association with the roots of susceptible, resistant and non-cotton hosts as well as in seed. Management of Fusarium wilt is difficult and most successfully achieved through the use of resistant cultivars and pathogen-free cotton seed. Once inoculum has been introduced into the field, strategies such as soil solarization and fumigation are applied to manage inoculum levels. While experimentally successful, these techniques are of limited use in a commercial setting. Management of Fusarium wilt will continue to rely upon the development of new resistant cultivars. Additionally, understanding the mechanism of seed colonization and developing high throughput seed treatment and testing protocols will allow the industry to effectively avoid the introduction of inoculum.