II.16 Improving the Economics of Grasshopper Bait Application: Efficacy and Swath Comparison of an Experimental and Standard Aircraft Spreader

Using solid baits, particularly carbaryl–wheat bran bait, for controlling or suppressing grasshoppers on rangeland has gained renewed attention in recent years. During the 1950’s, use of bait declined as use of effective small amounts of chemical sprays increased. Renewed interest in the use of baits was a direct result of improvement in aerial application equipment and the development of calibration procedures that produced con-sistent results. Increasing concern for the environment and the environmental advantages inherent with baits over many chemical sprays spurred these improvements. Grasshopper density management studies conducted in North Dakota in the mid-1980’s relied on and success-fully demonstrated these advances (Foster and Roland 1986). However, narrow swaths produced by the equip-ment used for aerial application of bait treatments in these studies demonstrated the competitive edge that was still associated with the wider swaths of aerially applied chemical sprays. The narrow swath, while hindering the wide-scale use of baits from the air, led to the development and production of an experimental aircraft spreader with an improved swath width. Jack Henderson and the New Mexico State University designed and produced an improved spreader and incorporated further modifications during the lat