COMBINATION OF TRICHODERMA-KONINGII WITH FLUORESCENT PSEUDOMONADS FORCONTROL OF TAKE-ALL ON WHEAT

Trichoderma koningii significantly reduced the severity of take-all of wheat caused by Gaeumannomyces graminis var. tritici in growth-chambe r 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. Vern on, WA, and reduced crown root infection by G. graminis var. tritici o n winter wheat by 40% at Pullman, WA. T. koningii was generally more s uppressive of take-all than Pseudomonas fluorescens Q29z-80 or a mixtu re of P. fluorescens and P. putida strains at both sites. In field tri als, the combination of Z koningii and Q29z-80 increased yield compare d to Q29z-80 alone but was not different from T. koningii alone. In gr owth-chamber experiments, combinations of T. koningii and any of six b acterial treatments provided substantially better disease control than the bacterial treatments applied alone. Combinations of T. koningii a nd certain bacterial treatments (e.g., P. chlororaphis 30-84, P. fluor escens Q2-87, and a four strain mixture) provided greater suppression of take-all than T. koningii alone. All combinations of T. koningii an d fluorescent pseudomonads were compatible.