Companies like Monsanto claim that genetically engineered (GE) crops help farmers produce higher yields with fewer chemical herbicides, but how legitimate is that claim?

Monsanto says that its GE products "help farmers around the world produce more while conserving more." A recent report from the Organic Center takes a hard look at one facet of GE crops where less is certainly not more: genetically modified crops' impact on herbicide use.

The report analyzes 13 years of USDA reports on pesticide use and concludes that:

GE crops are pushing pesticide use upward at a rapidly accelerating pace. In 2008, GE crop acres required over 26% more pounds of pesticides per acre than acres planted to conventional varieties. The report projects that this trend will continue as a result of the rapid spread of glyphosate-resistant weeds.

What's causing the increase?

In the first three years that they were on the market, GE seeds actually did require fewer pesticides to grow, so what changed?

First, a little background on how these herbicide-resistant crops work. Monsanto engineers these plants to be resistant to Roundup which is an herbicide they produce. The chemical's technical name is glyphosate. These GE crops allow farmers to spray their fields liberally with the stuff, rather than having to spray just the weeds. So-called Roundup Ready (RR) plants are made to survive so just the weeds die.

The main problem here is that weeds are now becoming resistant to glyphosate (pdf):

The widespread adoption of glyphosate-resistant (GR), RR soybeans, corn, and cotton has vastly increased the use of glyphosate herbicide. Excessive reliance on glyphosate has spawned a growing epidemic of glyphosate- resistant weeds, just as overuse of antibiotics can trigger the proliferation of antibiotic-resistant bacteria.

By relying on one method for weed control, we're breeding super weeds. Farmers have responded by dramatically upping their herbicide use.

Roundup, of course, doesn't just kill the weeds. Glyphosate contamination has been detected in humans who work around Roundup and their families and children. According to a research article from Environmental Health Perspectives symptoms of contamination in humans includes swollen eyes, face and joints; facial numbness; burning, itching skin; blisters; rapid heart rate; elevated blood pressure; chest pains, congestion; coughing; headache; and nausea.

While the EPA says that Roundup does not leech into groundwater supplies in significant amounts, Denmark imposed a ban in 2003 when a study found that the chemical had contaminated the groundwater there.

What can we do about it?

With Monsanto execs holding high positions at the FDA, it's more important than ever that we get active.

The Organic Consumers Association makes it easy to let Monsanto know how you feel about genetically engineered crops. You can also write your Congressperson and let him or her know how you feel about Roundup Ready crops.

The other great tool at your disposal is your wallet. When you choose organic, especially cotton, sugar, corn, and soybeans, you're sending a message that consumers care about GE crops' impact on their health and the environment.

Image Credits:
Spraying Pesticides. Both photos Creative Commons photos by tjmartins
Stop the Spray. Creative Commons photo by kevinkrejci