The potential of antagonistic fungi for control of Fusarium graminearum and Fusarium crookwellense varies depending on the experimental approach.

Abstract

To investigate the potential of fungal antagonists to control Fusarium head blight (FHB) causing pathogens (Fusarium graminearum and F.crookwellense) with two different experimental approaches. Using two invitro tests, Clonostachys rosea, Cladosporium cladosporioides and 10 Trichoderma strains were screened. In a co-culture assay, all Trichoderma strains significantly reduced the colony area of F.graminearum and F.crookwellense by 45-93%, whereas C.rosea and C.cladosporioides were not effective. In another assay, all antagonists from a chosen subset reduced the number of perithecia and ascospores on wheat straw by 88-100% when inoculated before the pathogen. Only C.rosea, a weak antagonist in the co-culture assay, was effective when inoculated after the pathogen, reducing perithecia and ascospore production by 73 and 100%, respectively. For screening antagonists and to avoid sorting out highly effective strains, it is crucial to consider different experimental approaches since the efficacy might differ substantially depending on the incubation conditions. By using two distinct experimental set-ups, we identified promising biological control agents. FHB is one of the most devastating fungal cereal diseases worldwide. As the pathogen overwinters on crop residues, application of antagonists on residues of the previous crop during harvest could be a promising approach to efficiently control FHB in cereals as an essential part of an integrated disease management.