Subodh Varma | TNN | NEW DELHI: A new study of genetically modified (GM) soybean and maize farming in US has found that even when the insecticide use has dipped, herbicide use has increased considerably, raising environmental concerns. Herbicides are used to kill weeds and the researchers say that its increased use is because of growing resistance among weeds leading to proliferation of 'super-weeds'.
This is the largest study of genetically modified crops and pesticide use till date. It was led by Federico Ciliberto, alongside Edward D Perry of Kansas State University, David A Hennessy of Michigan State University and GianCarlo Moschini of Iowa State University. The four economists studied annual data from more than 5,000 soybean and 5,000 maize farmers in the US from 1998 to 2011, far exceeding previous studies that have been limited to one or two years of data.