Bt Cotton: Yields up in India; pests low in Arizona
By Susan Milius
The two cotton-growing centers could hardly differ more. But small farms in India and industrial fields in Arizona both provide case studies that show the bright side of a widespread genetically engineered crop.
The crop, Bt cotton, has borrowed a toxin gene from the bacterium Bacillus thuringiensis to make its own pesticide. According to a report in the Feb. 7 Science, Bt cotton has raised yields some 80 percent on small farm plots in India compared with neighboring plots growing conventional cotton. It’s the first time that tests have found a whopping yield improvement from switching to a Bt crop, says agricultural economist Matin Qaim of the University of Bonn in Germany. The same jump might also show up in other tropical and subtropical farming regions, say Qaim and coauthor David Zilberman of the University of California, Berkeley.