Common use of genetically modified crops leading to rise in pesticide, herbicide use

Use of genetically modified crops has become commonplace in agriculture, but has led to an increase in use of pesticides and herbicides, according to a new study. Weeds and pests have have adapted to the modified crops and become resistant to the chemicals used to protect them, so farmers have been forced to spray crops with increasing amounts of the chemicals. The use of pesticides increased by 404 million pounds from 1996 to 2011. Herbicide use increased by 527 million pounds, and insecticide use by 123 million pounds.

Charles Benbrook, lead author of the Washington State University study, said it "undermines the value of both herbicide-tolerant crops and insect-protected crops," Carey Gillam of Reuters reports. Monsanto's Roundup Ready seeds were a hit with farmers, who enjoyed the benefits of being able to spray their entire crop, killing weeds and bugs without hurting their crops. However, more than two dozen weed species have become resistant to Roundup.

The amount of herbicide needed to fight "superweeds" is increasing by about 25 percent every year, Benbrook said. The annual increase has risen to 90 million pounds in 2011, up from 1.5 million in 1990. Insecticide use dropped 28 percent from 1996 to 2011, but is now rising, Benbrook said. (Read more)