(…) Genetically engineered crops do little to improve yields and instead promote the proliferation of herbicide-resistant weeds that actually curb production, according to a study by the Union of Concerned Scientists. Corn and soybeans modified to resist insects and the herbicide glyphosate haven't been proven to boost yields, the Cambridge, Massachusetts-based group says in a 44-page report. The modified plants have increased the number of glyphosate-resistant weeds that compete for soil nutrients and moisture, reducing production, the group says.(...)

The news:

http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=10567436

The Union of Concerned Scientists Website:

http://www.ucsusa.org/

The Report:

http://www.ucsusa.org/food_and_agriculture/science_and_impacts/science/failure-to-yield.html

http://www.ucsusa.org/assets/documents/food_and_agriculture/failure-to-yield.pdf

Basic Information on the Union of Concerned Scientists:

http://en.wikipedia.org/wiki/Union_of_Concerned_Scientists