Aspects of antagonisms between micro-organisms in soil

Summary Attention is called to certain aspects of microbial antagonisms in soil. Tests on the interaction of 90 strains of actinomycetes, isolated by non-selective procedure from the rhizosphere of potatoes grown in scab-infected soil which had been favorably modified by organic amendment, showed that within a group of 11 strains, found to be antagonistic toStreptomyces scabies, a wide range of cross-antagonisms existed. The possible importance of this in the study of specific antagonist-pathogen relationships is indicated, as well as that of the 'rhizosphere effect' in modifying the microbiological equilibrium in soil.Contribution No. 272 (Journal Series) from the Division of Bacteriology and Dairy Research, Science Service, Department of Agriculture, Ottawa, Canada.