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

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. (C) 2002 Elsevier Science Ltd. All rights reserved.