NY306 - Fungicide Resistance in Isolates of Botrytis from Ornamentals and Development of Control Strategies

In NSW nurseries, a 1993-96 study of resistance to fungicides for control of botrytis in ornamentals found that neither the benzimidozole fungicides (like benomyl) nor the dicarboximide fungicides (like iprodione) could be relied on to provide effective control of infections. The protectant, chlorothalonil, was the only fungicide available for use on all ornamentals in commercial practice. This report outlines further work to assess a range of fungicides and biocontrol agents for their efficacy against botrytis and their risk of building resistance.