Control of Green Peach Aphid, 1979

A peach orchard at Smith Tract, Orondo, Washington, was selected for this test. The orchard was a mixture of early and late maturing peach varieties. Three separate plots were used in the same orchard for three different insecticide timing tests. Four single tree replicates were used in a randomized block design for each treatment. The timings were bud break on Apr 4 (Table 1), pink on Apr 11 (Table 2) and post-bloom on May 17 (Table 3). All plots were sprayed to the point of drip (400 to 500 gal per A) with handguns at 400 to 500 psi. Five terminals were collected at random from each tree. Early season counts were made by examining individual terminals under a binocular microscope. The last count was made by placing all terminals from a tree in a Berlese funnel with an overhead light source to force the aphids down. Aphids were collected in vials filled with 95% alcohol at the bottom of funnels. Alcohol was filtered through filter paper and allowed to dry. The aphids were counted on the filter paper under a binocular microscope. See tables for the dates different sample methods were used.