Advocates of biotech crops and those who favor traditional farming practices such as crop diversity often seem worlds apart, but a new study shows that these two approaches can be compatible. The study, published in Nature Biotechnology, discovered that the diverse patchwork of crops in northern China slowed adaptation to genetically engineered cotton by a wide-ranging insect pest.
Genetically engineered cotton, corn and soybean produce proteins from the widespread soil bacterium Bacillus thuringiensis, or Bt, that kill certain insect pests but are harmless to most other creatures including people. However, rapid evolution of resistance to Bt toxins by some pests has reduced the benefits of this approach.
To delay resistance, farmers plant refuges of insect host plants that do not make Bt toxins, which allows survival of insects that are susceptible to the toxins. When refuges near Bt crops produce many susceptible insects, it reduces the chances that two resistant insects will mate and produce resistant offspring.
Yet, the Chinese approach relies on the previously untested idea that refuges of non-Bt cotton are not needed there because the most damaging pest, the cotton bollworm (Helicoverpa armigera), feeds on many crops other than cotton that do not make Bt toxins, such as corn, soybean and peanuts.
The results reported in the new study provide the first strong evidence that these “natural refuges” of non-Bt crops other than cotton delay evolution of pest resistance to Bt cotton.
“The most important lesson is that we don’t need to choose between biotechnology and traditional agriculture,” said Bruce Tabashnik at the University of Arizona’s College of Agriculture and Life Sciences. “Instead, we can use the best practices from both approaches to maximize agricultural productivity and sustainability.”
Read full, original article: Ancient wisdom boosts sustainability of biotech cotton
