Preliminary studies on biological control of the Fusarium ear blight complex of wheat

Abstract

Pre-inoculation of wheat ears at anthesis in the glasshouse with two non-host pathogens and the cell-free germination fluids of three Fusarium ear blight pathogens resulted in significant reductions in disease development and severity caused by Fusarium culmorum, F. avenaceum, F. poae and Microdochium nivale. Ears pre-inoculated with Phoma betae and challenged with F. culmorum showed over a 60% reduction in symptoms relative to the control treatment after 25 days. Over a 140% increase in incubation period relative to the control occurred when wheat ears pre-inoculated with Pythium ultimum were challenged with M. nivale, and a 75% increase in latent period occurred when ears pre-inoculated with M. nivale germination fluid were challenged with conidia of M. nivale. Although treatments did not significantly affect thousand grain weights, pre-inoculation of wheat ears with either P. ultimum or P. betae often resulted in a significant increase in number of grains per ear compared with equivalent germination fluid treatments, and a decrease in the level of Fusarium infection in harvested grain. Possible mechanisms for the observed effects are discussed.