The Verticillium wilt problem in Australian cotton

Verticillium dahliae is a soil-borne phytopathogen and the causal agent of Verticillium wilt. It affects many agriculturally important crops around the world, including cotton. In Australia, the billion-dollar cotton industry is increasingly impacted by Verticillium wilt. Internationally it has been reported that the defoliating V. dahliae Vegetative Compatibility Group (VCG) 1A causes severe damage to cotton. In Australia however, the non-defoliating VCG2A is causing more severe damage to crops in fields than the defoliating VCG1A. This review examines the current research to understand the Australian V. dahliae situation, including current classification systems, genetic analyses and management strategies. It appears that virulence cannot be defined solely by VCG in Australian Verticillium dahliae isolates causing disease in cotton, and that the industry must continually adapt their practices in order to keep the disease under control.