Top Consumer Questions about GMOs
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Many consumers ask whether farmers who grow GMO crops are increasing their use of pesticides. Overall, pesticide applications have decreased, largely due to the adoption of insect-resistant crops, particularly in cotton (Agricultural economist Graham Brookes discusses in this post.)
Reducing pesticide applications saves farmers time and money by decreasing the amount of chemicals they need to purchase and the number of times they need to apply them to fields over the course of a growing season. This also has translated into documented benefits to the environment including the reduction in greenhouse gas emissions, equivalent to taking 10.2 million cars off the road for one year (GM Crops: Global Socio-Economic and Environmental Impacts 1996-2011, Graham Brookes & Peter Barfoot).
Graham also describes the benefit of herbicide-tolerant GM technology, stating that the “volume of herbicide used in GM corn crops decreased by 193 million kg” from 1996 to 2011. That’s more than a 10 percent reduction.” The use of one herbicide, glyphosate has increased however, as farmers sought to adopt herbicide-tolerant crops and to use more benign chemicals on their farms. Although the use of one herbicide has increased, this has not led to an increase overall. This has also raised questions about weed resistance to glyphosate, which John Soteres addresses in this answer.
Let’s first explore why farmers use pesticides to better understand the role GMOs can play…
Why are pesticides used?
Farmers use pesticides to stop unwanted predatory insects and invasive weeds from destroying their crops. Just as gardeners deal with caterpillars that can wreak havoc on their fruits and vegetables, farmers manage for a variety of pests that interfere with crop production, reducing yield and increasing costs to the farmer and consumer. (Did you know that the same Bt pesticide you may use in your home garden is what helps insect-resistant GM crops fight pests?)
How do GMOs play a role in reducing pesticides?
Several GM crops have been developed specifically for insect resistance or herbicide tolerance, which allows farmers to use fewer pesticides on GM crops. For example, the European corn borer is one of corn’s primary pests. It can damage the ears and stalks of corn by chewing tunnels, damaging the plant and inhibiting growth. Farmers can control for this pest by planting GM corn resistant to the European corn borer, which reduces the need for pesticides and helps increase yield by preventing damage to the corn crop.
Agricultural economist Graham Brookes discusses insect resistance in GM crops in this post, stating that it “provides a form of protection against pests and often replaces insecticides as a form of control.” Brookes goes on to say that “the use of GM insect-resistant technology has resulted in major reductions in the use of insecticides that have been traditionally used to control the pests the GM technology now controls.”
Furthermore, Andrew Kniss, a weed ecology and management professor at the University of Wyoming, explains how herbicide-resistant crops allow farmers to use fewer toxic herbicides in the field in this post.
This presentation from the Federal Department of Economic Affairs, Education and Research (EAER) in Switzerlanddetails the role of insect-resistant GM technology in the context of IPM. This article discusses how GM crops can help make agricultural production more efficient while reducing the environmental impact of pesticides.
For more information on pesticides and GM crops, check out these responses:
- Today, someone tweeting the following: “Did you know? With the introduction of GMOs in our food, pesticide use went from 1.5 million pounds in 1999 to 90 million pounds in 2011.” Is this accurate?
Answered by David Tribe: http://gmoanswers.com/ask/today-someone-tweeted-following-did-you-know-introduction-gmos-our-food-pesticide-use-went-15
- Is it true that GMOs require massive amounts of pesticides, herbicides and fungicides?
Answered by Jim Gaffney: http://gmoanswers.com/ask/it-true-gmos-require-massive-amounts-pesticides-herbicides-and-fungicides