THE CONTROL OF FUSARIUM BLIGHT IN OAT SEEDLINGS WITH ANTAGONISTIC SPECIES OF CHAETOMIUM

Abstract

Forty‐seven isolates representing twenty‐seven species of Chaetomium were tested for their ability to control seedling blight of oat seedlings caused by Fusarium spp., chiefly F. nivale (Fr.) Ces. In pot tests the majority of the isolates were ineffective, but certain isolates of Chaetomium cochliodes Pall, and C. globosum Kunze gave a large measure of control and were as effective as an organic mercury seed dressing. Control of disease was also obtained when living material was attached to the surface of oat seed and when infested seed was soaked in cell‐free filtrates from cultures of isolates which reduced disease in vivo. Substantial control of disease was obtained when infested seed was sown in soil to which cultures of C. cochliodes had been added 10 months previously. This antagonist was able to grow through unsterile soil in the presence of certain added substrates. The results of pot experiments were confirmed in field experiments. Isolates of Chaetomium which controlled disease in pot and field experiments were not strikingly antagonistic to Fusariirm nivale in pure culture on agar media.