Allelopathic potential of wheat accessions /

Abstract

Root exudates of 286 accessions of hard red winter wheat (Triticum aestivum L.) were compared with that of a commercial strain 'T 64' for their relative ability to inhibit root and shoot growth of Japanese brome (Bromus japonicus L.) and common lambsquarters (Chenopodium album L.). Five accessions produced root exudates significantly more inhibitory to root growth in indicator plants than the commercial strain. When Japanese brome was grown in the presence and absence of wheat in sand cultures, wheat significantly retarded growth of the brome, with two of the test accessions of wheat significantly more effective than 'T 64' in reducing weed growth. When CI 13633 was grown with Japanese brome on a one-on-one basis in U-tubes containing aerated Hoagland's solution, growth of the brome was approximately 53% of that obtained by growing it with 'T64'. Respiration rates of roots and shoots of young seedlings and of newly emerged whole seedlings of Japanese brome were significantly reduced by root exudates from two of the test accessions. The consistent and superior inhibition of the indicator species by the test accessions indicates a strong allelopathic character which could be incorporated into commercial cultivars.