Seedling blight. IV. Effect of source of isolates of Pythiaceae on percentage stands of poppies and peas on four steamed soils

Abstract

The pathogenicity of two species of Pythiaceae, as assessed by percentage stands of poppies and peas on reinfested steamed soils, is influenced by five of the six factors investigated. The factors include strains that differ in pathogenicity, the species of host yielding the isolate, and the soil on which the host was grown. The other factors operate during the actual testing of pathogenicity of the isolate. They are the species of host being tested and the steamed soil on which the host is grown. The pathogenicity of an isolate to each species of host is generally consistent over the various soils.