Crops with the internal ability to resist insects and other pests will require fewer applications of pesticides. This will mean fewer chemical residues will find their way into ground and surface water supplies and onto foods. Less land will have to be converted to agricultural use because of the increased yield of GE crops. Those in favor of biotechnology cite GEcorn as a positive example. When fed to hogs, GEcorn will reduce the phytic acid in animal waste that contributes to algae growth in water. Another proposed advantage of genetic engineering is that it would increase the genetic variation in staple crops by breeding into them desirable traits from previously unavailable sources. Researchers aim to use biotechnology to discover which genes of value reside in which plants and then transfer those genes into crops now in use around the globe. It will enable scientists to learn what important genes are actually contained in the millions of plant specimens housed in gene banks around the world.

Scientists favoring genetic engineering claim there is no scientific evidence that “superpests” or “superweeds” could occur through GE foods. Insects and weeds naturally develop resistance to chemicals in their environment. Biotechnology can better manage this evolution in resistance. There are already systems in place-crop rotation, hybrid rotation, and insect resistance management-that help prevent resistance from developing. With regard to insects developing resistance to Bt crops, supporters point to the practice of insect resistance management (IRM). This is a practice in which growers plant non-Bt crops near the genetically modified resistant plants. Pests infecting these non-Bt plants will not develop Bt resistance and will breed with their counterparts in the Bt crop fields, which will lessen the chances of the development of resistance. Proponents argue that research demonstrating the possibility of resistance has been done in the laboratory, and thus may not be applicable to the natural environment.