Navel Orangeworm Control on Walnuts, 1983

Tests were conducted at the Westside Field Station at Five Points, Calif. Five treatments were replicated eight times using a randomized complete block design. Each replicate consisted of an individual tree. Materials were applied to run off (540 gal spray mixture per acre) with a handheld orchard sprayer operating at 200 lb/in2. Applications were made on 31 Aug. when the walnut husks had just begun to split. Control was evaluated by inspecting 100 nuts per tree for navel orangeworm and codling moth damage or larvae on 5 Oct. Spider mite control was evaluated on 7, 14, and 23, Sept. and 5 Oct by counting the number of mites on 10 terminal leaflets per tree.