VIEW ARTICLE

Disease Control and Pest Management

Combination of Trichoderma koningii with Fluorescent Pseudomonads for Control of Take-all on Wheat. Brion K. Duffy, Department of Plant Pathology, Washington State University, Pullman 99164-6430, Current address: Phytopathology Group, Swiss Federal Institute of Technology, Universitätstrasse 2, CH-8092 Zürich, Switzerland; Andrew Simon(2), and David M. Weller(3). (2)Commonwealth Scientific and Industrial Research Organization (CSIRO), Division of Soils, Private Bag 2, Glen Osmond 5064, South Australia, Australia; (3)Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164-6430. Phytopathology 86:188-194. Accepted for publication 1 November 1995. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1996. DOI: 10.1094/Phyto-86-188.

Trichoderma koningii significantly reduced the severity of take-all of wheat caused by Gaeumannomyces graminis var. tritici in growth-chamber experiments and slightly enhanced the growth of wheat in the absence of G. graminis var. tritici. In field trials, T. koningii applied to the seed furrow increased the yield of spring wheat by 65% at Mt. Vernon, WA, and reduced crown root infection by G. graminis var. tritici on winter wheat by 40% at Pullman, WA. T. koningii was generally more suppressive of take-all than Pseudomonas fluorescens Q29z-80 or a mixture of P. fluorescens and P. putida strains at both sites. In field trials, the combination of T. koningii and Q29z-80 increased yield compared to Q29z-80 alone but was not different from T. koningii alone. In growth-chamber experiments, combinations of T. koningii and any of six bacterial treatments provided substantially better disease control than the bacterial treatments applied alone. Combinations of T. koningii and certain bacterial treatments (e.g., P. chlororaphis 30-84, P. fluorescens Q2-87, and a four strain mixture) provided greater suppression of take-all than T. koningii alone. All combinations of T. koningii and fluorescent pseudomonads were compatible.