Incidence of Cochliobolus sativus in Queensland wheat crops

Abstract

Environmental and soil conditions in Queensland are widely different from those in Saskatchewan, Canada, yet Cochliobolus sativus (Ito & Kuribay.) Drechsl. ex Dast., the dominant fungus pathogen responsible for common root rot of wheat in Saskatchewan, is also a component of the root and crown rot complex in Queensland. During the 1964 wheat season a survey of 24 fields, comprising a variety of soil types, revealed that 22 % of the wheat plants sampled were infected with C. sativus. In individual fields the incidence of C. sativus ranged from 0 to 76%. About half of the fields either were free of the organism or had a very low incidence. This possibly is a reflection of the great diversity of crops grown on the grey-black clays and brigalow soils of Queensland and demonstrates the possibilities of control of C. sativus through crop rotation.