Growth of the pathogen is favored by cool, moist nights and warm days. Certain cultivars are more susceptible. It is important to alternate benomyl with materials of a different chemistry. All three applications may be necessary in seasons when there is cool weather with occasional rain.
Early treatments are the most important and most effective.
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies. A strobilurin fungicide. Do not apply more than two applications before alternating with a fungicide that has a different mode of action. Do not apply within 3 weeks of an oil application. Do not apply within 3 weeks of an oil application.