Control of Powdery Mildew in Vineyards Using Single-Application Vapor-Action Treatments of Triazole Fungicides

The triazole fungicides etaconazole, flusilazole, myclobutanil, penconazole, triadimefon, and triadimenol were applied as formulated products to cheesecloth wicks. The treated wicks, containing fungicide at the rate of 0.2-4.0 g a.i. per vine, were hung beneath the fruiting zone in the grapevine trellis during the period between bloom and 2 wk after shatter. Although no further fungicide treatments were applied for the growing season, fruit in treated vines in the most effective treatments remained free of powdery mildew until harvest. Control of powdery mildew was observed in a zone having a radius of approximately 45 cm from the treated cheesecloth