Scientists today began innoculating an acre of corn stalks in the first field test of a genetically engineered microbe designed to combat the European corn borer, one of agriculture's most destructive pests. Although researchers have conducted other experiments of genetically altered materials in the environment, the tests of Cxc-Bt at the federal experimental station here are the first approved of a genetically altered ``plant vaccine,'' scientists and federal officials said. Proponents of the Crop Genetics International project call the testing a step toward an era of chemical-free pest control. The company's chief scientist, Peter Carlson, said today he hoped Cxc-Bt will have the effect of making the corn borer sick. But he said the main purpose of the test is to determine whether the pesticide will spread from plant to plant, an undesireable effect. The microbe works by attacking the alkaline stomach of corn borers, giving them ulcers. It doesn't affect humans because people's stomachs are acid and are unaffected by the Bt protein, according to researchers. In previous experiments in petrie dishes and in a greenhouse, the microbe killed the borers in the petrie dishes and sickened them when tested in the greenhouse. The pest costs American farmers $400 million annually. Critics worry that Cxc-Bt experiment could set a precedent and are concerned that genetically engineered materials could spread uncontrollably once released into the environment. Environmental groups, including the National Audubon Society and the Environmental Defense Fund, did not oppose the limited field tests begun today. Environmental experts said if their questions about spreading are answered with more tests, they may support the final product. The crucial question for environmental groups is whether there will be adequate testing and regulation because Cxc-Bt is just the beginning of a rush of dozens, perhaps hundreds, of similiar products, said Maureen Hinkle, the Audubon Society's director of agriculture policy. Only one other genetic crop protector, a microbe altered to fight frost, has been approved for field testing by the U.S. Environmental Protection Agency. Jeremy Rifkin, president of the Washington-based Foundation on Economic Trends, said the pesticide hasn't been shown to work in greenhouse tests. Rifkin said today his organization did not oppose today's test because ``this product doesn't work. It does not kill corn borers. (The company's) evaluation data supplied to the EPA shows the product does not kill the insects. It poses no immediate threat because it doesn't work.''
