Biological control of fusarium head blight of wheat with Clonostachys rosea strain ACM941

A strain of Clonostachys rosea, ACM941 (ATCC #74447) was evaluated for its antibiosis to G. zeae in vitro and for controlling of fusarium head blight (FHB) under both greenhouse and field conditions, in comparison to the registered fungicide Folicur(tebuconazole). ACM941 reduced the mycelial growth of the pathogen by 53% in dual culture and completely suppressed the macroconidium germination of G. Zeae in co-culture for 6 hours. ACM941 reduced the perithecium production by more than 99% in leaf disc assay, 23-57% on debris, and 36-70% on infested kernels. When sprayed onto wheat heads prior to inoculation with G. zeae, ACM941 significantly reduced infected spikelets (IS) by 58-71% and fusarium damaged kernels (FDK) by 59-73% compared to the untreated disease control. Under the simulated natural epidemic conditions during 2005-2007, ACM941 reduced IS by 44-51%, FDK by 33-68%, and deoxynivalenol (DON) in grains by 10-28%. ACM941 was similar to Folicur in reducing the mycelial growth, spore germination, and perithecium production of G. zeae, but was less effective than Folicur in reducing IS, FDK, and DON in the field, Results of this research suggest that ACM941 is an effective antagonist against G. zeae and may be used as an alternative of chemical fungicides in an integrated FHB management program.