Development of new crop varieties through genetic engineering offers a broad spectrum of potential benefits, including reduced production costs, enhanced yields, and enhanced nutritional or other characteristics that add to value. Among the first developments on the market were changes in the genetic makeup of common field crops that made them tolerant to commonly used glyphosate herbicides, or that incorporated genes of the natural pesticide Bacillus thuringiensis (Bt), so that plants produce a protein toxic to specific insect pests.These varieties appealed to producers because they promised to simplify pest management and reduce pesticide use, while helping to control costs, enhance effectiveness of pesticides (both herbicides and insecticides), and increase flexibility in field operations. Evidence of that appeal lies in the rapid adoption of genetically engineered crops, beginning with very little U.S. acreage in 1996 and reaching 41 percent of major crop acreage in 2000, down from 49 percent in 1999.The potential to reduce pesticide use through genetic engineering, or biotechnology, could also appeal to consumers. A Farm Bureau/Phillip Morris poll of farmers and consumers in August 1999, for example, indicates that 73 percent of consumers were willing to accept genetic engineering as a means of reducing chemical pesticides used in food production. The poll also found that 68 percent considered farm chemicals entering ground and surface water to be a major problem.