Control of Alfalfa Insects in Iowa (Early Season), 1985

Experimental plots measuring 20 × 40 ft were established in a 2-yr-old stand on the Ankeny Research Farm near the city limits of Ankeny, IA. Eighteen treatments were replicated 4 times in a randomized complete block design. Insecticide treatments were applied on May 9 ’85 with a Suzuki LT-125 4-wheel all terrain cycle equipped with a 20-foot boom. The CO2 charged (31 psi) boom was ca. 18 inches from the foliage and fitted with 12 brass 8003 flat-fan nozzles. Ground speed was 3.9 mph delivering 12 gal of final solution per acre. Plants were in stage 3 (early bud) and ca. 23 inches tall. Weather conditions at application time were partly cloudy, winds 0-4 mph, temperature 65-75 degrees F, and ca. 70% RH. A standard 15-inch sweepnet was used to take 10 pendulum sweeps in each plot 2 days before treatment and 1, 4, and 7 days posttreatment. No phytotoxicity was observed in any plot.