Suppression of sporulation of Botrytis cinerea by antagonists applied after infection

The ability of the antagonists Epicoccum nigrum, Gliocladium roseum and Trichoderma harzianum to reduce sporulation of Botrytis cinerea when applied after infection was investigated in bean-leaf-disc assays under a variety of environmental conditions. G. roseum significantly reduced sporulation of B. cinerea when applied up to 120 h after the pathogen, whereas E. nigrum and T. harzianum suppressed sporulation when applied up to 72 h after infection. When applied 48 h after infection, all antagonists reduced sporulation of B. cinerea at temperatures of 15-25 degreesC. G. roseum was highly effective at reducing sporulation of B. cinerea throughout this temperature range, but not at 10 degreesC, whereas E. nigrum and T. harzianum showed their greatest relative effects on sporulation at 25 degreesC. Antagonism by G. roseum was favoured by relative humidity of 98%, while the effect of relative humidity on E. nigrum and T. harzianum was equivocal. Under the conditions of the assay system, antagonist concentration did not have a consistent effect on reduction of sporulation.