EVALUATING POTENTIAL ENVIRONMENTAL-IMPACT OF INSECTICIDE APPLICATIONSIN A BOLL-WEEVIL ERADICATION PROGRAM

Concerns have been expressed about the potential insecticide contamina tion of regional water resources from a bell weevil eradication progra m in Oklahoma. A mathematical model and geographic information system techniques were utilized to evaluate the potential of insecticide leac hing and runoff from a major proposed program area in the state. Diffe rent but equally likely weather patterns were generated, and potential insecticide losses associated with each pattern were predicted. Soil types and their locations within cotton areas were identified, and pot ential chemical losses from each soil were delineated. Model simulatio ns indicated that azinphos-methyl and diflubenzuron could leach from s ome porous soils and that all insecticides suggested for use in the pr ogram could be lost to runoff. The predicted chemical movements with r unoff were significantly higher on irrigated land than from non-irriga ted land. Malathion demonstrated no leaching and low potential of runo ff losses among the insecticides evaluated.