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Abstract
The Passamaquoddy Indian Forestry Department treated 40,300 acres in Maine in 1983 using Bt to protect red spruce and eastern hemlock from spruce budworm damage. The post treatment evaluation indicated that the protection objectives were achieved. In cooperation between the Passamaquoddy Indian Forestry Department and two commercial Bt suppliers, Abbott Laboratories and Zoecon Corporation, four commercial products were applied as eight field formulations. Where possible, these treatments were compared for effectiveness. The results show an average defoliation of 23 percent and population reduction from 864.5 budworms per 100 square feet of foliage to 62.5 budworms, or an average of 94 percent population reduction. The undiluted field formulations gave significantly (P = 0.05) less defoliation and greater population reduction than the diluted formulations. A method for spray deposit assessment using spruce foliage is presented.
Parent Publication
Citation
McCreery, Lew; Millers, Imants; Souto, Dennis; Francis, Bruce. 1985. Comparison of Bt formulations against the spruce budworm. In: Grimble, David G.; Lewis, Franklin B., coords. Proceedings, Symposium: Microbial control of spruce budworms and gypsy moths; 1984 April 10-12; Windsor Locks, CT. Gen. Tech. Rep. NE-100. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 23-27
