Resistance of other powdery mildews has already been demonstrated for compounds that have a similar mode of action, and fungicide resistance is common in this class of compounds. The current control programs for aphids, mites, downy mildew and powdery in all commercial production areas cannot be economically maintained and the currently available pesticides have already lost or are rapidly losing their effectiveness due to resistance development in the pest populations. Thus, current research efforts are directed toward integrating control measures to manage resistance development and reduce overall pesticide use, while still maintaining the ability to economically produce a crop. Research projects include testing pesticides for activity against multiple pests, development of rationale for when and how to use particular pesticides based on range of activity and resistance management, development of pest forecasting models for timing and use of pesticides, examining the utility of biological control agents, modifying cultural practices, and development of resistant varieties. This is a particularly appropriate time for this survey and education program.
Growers face a new disease and are receptive to implementing and integrating new control strategies.
The hop market is also depressed and hop acreage is declining. In a few years, when the current overproduction has been consumed, growers will again expand acreage. Newer cultural systems, which can result in lower pesticide use or enhanced disease and pest control, will look particularly attractive. Any changes that may be catalyzed over the next growing season may be amplified as acreage increase. We are not yet able to develop a plan for reduced pesticide use because we lack baseline pesticide use information.