Some factors affecting the survival of the cereal root pathogen Ophiobolus graminis in wheat straw

Abstract

The saprophytic survival of Ophiobolus graminis was studied under laboratory and field conditions using artificially-infected wheat-straw buried in a Victorian Mallee soil.In pot tests, survival was prolonged by applications of ammonium sulphate, unaffected by superphosphate dressings and reduced by growing oats over infected straw. The observed effect if the nitrogenous soil amendment was not dependent upon the presence of Rhizoctonia solani as reported for South African soils.In a field experiment, survival was reduced significantly more by growing various plant species over infected straws than by maintaining fallow conditions. O graminis was isolated from all species, including dicotyledons, sown over infected straw