Marketed as Roundup and other trade names, glyphosate is a broad-spectrum systemic herbicide used to kill weeds. About 95% of soybean and cotton crops and more than 85% of corn in the U.S. are planted to varieties genetically modified to be herbicide resistant.
“Resistant weeds have become a major problem for many farmers reliant on GE crops, and are now driving up the volume of herbicide needed each year by about 25%,” Benbrook says...
Overall pesticide use in 2011 was about 20% higher on each acre planted to a GE crop, compared to pesticide use on acres not planted to GE crops.
What else should we expect? We used DDT to kill mosquitoes; we created DDT resistant mosquitoes. Why wouldn't the use of GMO crops do the same thing?
The real gem is here, though: "The presence of resistant weeds drives up herbicide use by 25% to 50%, and increases farmer-weed control costs by at least as much." Guess who pays? And guess who benefits?