We have experience with Trichoderma against FHB. We spray a conidial suspension of the fungus when spikes are at 50% anthesis and we got interesting results. We produce spores for small scale plot experiments by growing Trichoderma isolates on Malt agar or on Oat Meal agar plates and then we collect spores by simply washing the plates. You can use also PDA plates, but it is a too rich medium, and the fungus produce a lot of mycelium that disturb spore harvesting.