By Andi Anderson
A new study reveals that excessive planting of genetically modified (GM) Bt corn has resulted in pest resistance and economic losses exceeding $1 billion. The research calls for more balanced seed use and diversified pest control strategies.
The Impact of Overplanting Bt Corn
Bt corn contains toxins from Bacillus thuringiensis bacteria, which are designed to repel pests like corn rootworm. However, widespread planting—more than 85% of US corn—is leading to increasing pest resistance.
The study analyzed crop damage from 2005 to 2016 and found that many farmers planted more GM corn than needed. The cost of Bt seeds is higher, and their benefits in certain states were marginal.
In Indiana, Ohio, and Michigan, farmers planted about 50% of their fields with Bt corn, but researchers suggest the optimal level was only 18%. Planting less Bt corn could have saved $99 million annually in these states.
Rising Resistance and Increased Costs
Pest resistance to Bt corn is now confirmed in at least six US states, and globally, 11 pest species in seven countries have developed resistance. As resistance grows, farmers rely more on synthetic insecticides, raising costs further.
The study also found that seed companies combine GM traits like herbicide tolerance with pest resistance, making it difficult for farmers to assess costs. Researchers suggest better labeling to detail the price of each trait.
Solutions for Sustainable Pest Control
Experts recommend reducing GM crop use, rotating crops, and planting conventional corn refuges to slow pest resistance. They also call for government programs to support genetic diversity in seed options. Without action, reliance on GM crops could lead to a cycle of increasing pest resistance and rising costs for farmers.
Photo Credit: getty-images-elhenyo
Categories: Indiana, Sustainable Agriculture