SUMMARYIn field experiments in New South Wales, wheat inoculated withGaeumannomyces graminisvar.triticihad less take‐all and yielded significantly more grain (P≤ 0·05) when simultaneously inoculated withG. graminisvar.graminisand a lobed hypho‐podiatePhialophorasp. synonymous withPhialophora radicicolaCain var.radicicola sensuDeacon than when unprotected with these fungi. An isolate ofP. radicicolavar.graminicoladid not confer any protection. The yields of cross‐protected wheat approached those of healthy wheat where take‐all incidence was slight to moderate while control was less economically significant where disease was severe. If this form of control proved similarly effective against natural inoculum it might be best employed at the beginning of a wheat monoculture after a break crop and serve to delay the onset of severe take‐all.A preliminary survey of 28 wheat fields in New South Wales using a bait technique and examining for characteristic fungal structures showed thatG. g. graminiswas rarely present in the soil and the lobed hyphopodiatePhialophorasp. andP. r. graminicolawere absent. Significant populations ofG. g. graminisonly occurred in first wheat crops after a long period of native pasture. In New South Wales, at least, these avirulent fungi would have to be introduced to wheat fields for take