Everyone's been waiting for long-term studies of GM crops - and now we have one!
The European corn borer was accidentally released in the U.S. in 1917. In recent years, it's managed to cost farmers $1 billion each year. Transgenic Bt corn was introduced in 1996, largely in order to deal with this pest. Thanks to the enthusiastic adoption of farmers, over 60% of U.S. corn now contains the borer-killing Bt gene...
This new study tracked impacts of Bt corn and the borer in 5 Upper Midwest states: Nebraska, Minnesota, Iowa, Illinois and Wisconsin (the first 4 are the top corn-producing states in the U.S.). Apparently, the Bt gene not only protects farmers who bought these transgenic seeds, but also produces a "halo effect" that protects conventional, non-transgenic corn plants - not only locally, but on a landscape level across the Midwest.
Cutting edge technology isn't cheap and it turns out it's the farmers who didn't buy high-tech Bt corn seed benefited the most - because they got residual corn borer protection without having to buy more expensive seed. Bt corn has saved Midwest farmers $6.9 billion over the past 14 years - and 63% of this savings was collected by growers of non-GM seed!
This is especially good news as farmers have recently been protesting corporate and governmental refuge regulations that forbid the planting of more than 80% of a farm in Bt-containing corn.* According to this study, the maximum profit could likely be made by planting only 50-60% of each farm in Bt-corn - thanks to the protective halo of Bt corn and the cheaper cost of non-Bt seed.
This is great news for managing pest resistance! According to the NPR interview, they're going to use this info to encourage farmers to plant proper refuges.
W. D. Hutchison,1,* E. C. Burkness,1 P. D. Mitchell,2 R. D. Moon,1 T. W. Leslie,3 S. J. Fleischer,4 M. Abrahamson,5 K. L. Hamilton,6 K. L. Steffey,7, M. E. Gray,7 R. L. Hellmich,8 L. V. Kaster,9 T. E. Hunt,10 R. J. Wright,11 K. Pecinovsky,12 T. L. Rabaey (2010). Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers Science, 330 (6001), 222-225
*Refuges = non-Bt corn that is planted among Bt corn to provide food for pests such as the corn borer. This process lowers the selective pressure on pests to evolve resistance to Bt, and is an important practice that extends the useful life of new pesticides.