CONTROL OF SPIDER MITES AND EUROPEAN RED MITES, 2001

This trial was conducted at the Northwest Michigan Horticulture Research Station in Traverse City, MI, in cooperation with MSU-Extension District IPM agent Gary Thornton. Three-tree plots were arranged in a randomized complete block design with four replications. The test materials were applied at threshold on 27 Jul to mature Montmorency tart cherry trees with an FMC 1229 air blast sprayer calibrated to deliver 60 gpa. Three fungicides commonly used on stonefruit, Bravo Weatherstik, wettable sulfur, and Nova were included in the test to evaluate possible flaring of mites. A maintenance application of Imidan 70 W was made on 30 Jul for control of cherry fruit fly. Mite evaluations were made on 19 Jul, 2 Aug, 10 Aug, 20 Aug, 28 Aug, and 4 Sep by picking 50 randomly selected leaves from each replicate and passing the leaves through a mite-brushing machine. Motile forms of TSSM and ERM were then counted with the aid of a microscope. ERM populations did not develop in this trial and therefore no data are reported. TSSM data are reported as the mean number of mites per leaf. Data were analyzed using ANOVA and means separation by LSD at P = 0.05.