Spring Management of Cooley Spruce Gall Adelgid with Highly Refined Horticultural Spray Oil, Insecticidal Soap, Tempo, and Sevin on Douglas-Fir in Lehighton, Pennsylvania, 1994

Abstract

Abstract Seven treatments were applied to evaluate Cooley spruce gall adelgid on heavily infested 6-8 ft Douglas-fir Christmas trees. Treatments were applied on 14 Apr, arranged in a RCB design, replicated 4 times. Foliar treatments were completed by using a Solo Master 412 back pack mist blower operating at full throttle on setting two. Treatments were applied at the rate of 150 gal/A (454 ml/tree). At treatment time the following conditions existed: air temperature, 69°F; 45%RH; water pH, 6-7; and skies were clear. Posttreatment counts were completed on 30 DAT. Each treatment was evaluated by selecting four cardinal locations on each tree at breast height, and counting the total number of life stages (nymphs, adult females with egg masses) over a 15 sec count on 1994 needle growth at each location. Each tree was rated on 1 Aug (109 DAT) to determine effect of treatments on needle quality. Each treatment was evaluated by selecting four cardinal locations on each tree at breast height, and counting the total number of Cooley spruce gall adelgid damaged 1994 needles over a 15 sec count.