Suppression of overwintering Botrytis cinerea inoculum on grape rachii using antagonistic fungi

Seven fungi were assessed for ability to suppress infection and sporulation of B. cinerea on sterilised grape rachii at 5, 10, 15 and 20°C.At 10-20°C, conidium production of B. cinerea was suppressed by all test isolates.The most effective Epicoccum, Scytalidium and Ulocladium isolates had conidium germination frequencies and germ tube growth rates greater than or comparable to that of B. cinerea at 10-25°C.Epicoccum and Ulocladium isolates were further tested for their ability to reduce overwintering B. cinerea on rachii in two vineyards.Their suppression of B. cinerea was low and inconsistent, but results were confounded by low B. cinerea levels in all treatments, possibly due to unseasonably warm, dry winter weather.