Control of Russian Wheat Aphid, 1988

A spring wheat field near Twin Falls, Idaho, was treated with 15 insecticide treatments on 24 Jun. The soil type was Portneuf silt loam and the field was irrigated by wheel line sprinkler systems. The first irrigation of the treated plot area was 2 DAT. The treatments and an untreated control were replicated 4 times in a randomized complete block design with individual plots of 12 by 24 ft. Treatments were applied as a broadcast spray using a CO2-pressurized backpack sprayer at 30 psi delivering 20 gal finished spray/acre. Nozzles were X-8 (Spraying Systems) hollow cone. The wheat was in the boot stage with about a third of the heads starting to emerge from the boot on the treatment date. On all sampling dates 10 tillers were cut from the center area of each plot and put into plastic bags. The bags were kept in a refrigerator until the RWA on each tiller were counted under a microscope.