Prevention of sporulation of Fusarium in plant residue to reduce FHB and DON

The goals of this project are to reduce Fusarium head blight (FHB) and DON in barley by reducing the in-field production of ascospores and conidia by Gibberella zeae (= Fusarium graminearum).

It has been demonstrated that spores produced in-field are important in the epidemiology of the disease so that reduction of this source of inoculum should result in a decrease in disease and the associated toxin. In addition, if this practice is adopted widely by farmers then the pool of spores originating from more widely dispersed fields will also be reduced, thus adding to a reduction in overall inoculum pressure experienced by the barley plant. The approach proposed is to use chemical and biological control agents that are already shown to be effective on the plant and to use them to inhibit the growth or perithecial development of the fungus while it is in its saprobic phase in plant residues.

In the field, sporulation of the fungus under the different treatments will be monitored ina second season by exposing barley spikes for fixed periods and then removing them, washing and counting, as well as use of spore traps. The impact of the reduction in sporulation on the incidence and severity of Fusarium head blight and DON toxin production in barley sown into chemical or biological treated stubble will be assessed.

In controlled environment experiments, a wider range of potential chemical and biological antagonists will be tested. Perithecial production under different treatments will be quantified and sporulation will be measured by trapping spores onto sticky surfaces placed above the treated plant residue.