Effectiveness of a Dormant Application of Sunspray 6E Oil for Controlling Eriophyid Mites on Established Common Baldcypress, 1994

Baldcypress trees, with an avg DBH of 16 inches, located on the property of Longwood Gardens, Kennett Square, PA, were used to evaluate the effectiveness of a dormant application of Sunspray 6E oil against eriophyid mites. On 11 Apr, trees were treated with a 2.5% solution of oil for an average of 57 gal of finished spray per tree. An SDI sprayer operating at 600 psi with a no. 50 Gun Jet hollow cone nozzle tip was used to apply the treatment. Treatment was performed between 6—8 AM during overcast conditions, 43°F, 40% RH, and <5 mph winds. Effectiveness of the treatment was evaluated on 25 Apr (14 DAT) and 13 Jun (63 DAT). On 25 Apr, 5 branchlets/tree were randomly chosen from 5 treated and 5 untreated trees. Starting from the terminal end, 25 leaves/branchlet were examined using a dissecting microscope and the no. of live mites was counted and recorded. On 13 Jun, 4 branches/tree were randomly chosen from 4 treated and 4 untreated trees. From each branch, four 3-inch-long branchlets, as measured from the terminal end, were examined using a dissecting microscope and the no. of live mites was counted and recorded.