VIEW ARTICLE

Ecology and Epidemiology

Use of Mixtures of Fluorescent Pseudomonads to Suppress Take-all and Improve the Growth of Wheat. Elizabeth A. Pierson, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164-6430; David M. Weller, Agricultural Research Service, U.S. Department of Agriculture, Pullman, WA 99164-6430. Phytopathology 84:940-947. Accepted for publication 2 June 1994. 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, 1994. DOI: 10.1094/Phyto-84-940.

Fluorescent Pseudomonas strains were tested alone and in combinations for the ability to suppress take-all in greenhouse and growth chamber tests and to enhance the growth and yield of wheat in fields infested with Gaeumannomyces graminis var. tritici. In general, certain combinations of strains enhanced yield, whereas other mixtures and strains used individually did not. Overall, the best combinations were Q2-87 plus Q1c-80 plus Q8d-80 plus Q65c-80, Q2-87 plus Q1c-80 plus Q8d-80 plus Q69c-80, and Q1c-80 plus Q8d-80 plus Q65c-80. For example, in a field test on spring-sown wheat at Pullman, WA, during 1989, the treatment Q2-87 plus Q1c-80 plus Q8d-80 plus Q65c-80 significantly (P = 0.05) increased yield 20.4% compared to a nontreated control, whereas each strain used individually had no significant effect on yield. This work demonstrates the potential benefits of using combination treatments to suppress take-all and suggests the importance of additive and interactive effects among introduced bacteria in biological control.