Good news for corn farmers worth millions of dollars
Good news for corn farmers: a major corn crop pest, the European corn borer (ECB) has seen a significant population decline in the eastern United States. This information comes from Penn State researchers on the heels of reports of similar population declines in the Midwest. As a result, farmers will save millions of dollars in some parts of the country because they will no longer need to treat for this pest.
"ECB, which was introduced to North America from Europe in the 1900s, used to be the most important pest of corn in the United States," said John Tooker, assistant professor of entomology. "Not that long ago, it caused crop losses that annually approached $1 billion nationwide, and $35 million in the northeastern United States."
According to Tooker, to protect their crops from ECB, many farmers have grown a genetically modified type of corn that expresses insecticidal toxins that kill the worms. These toxins were isolated from the bacterium Bacillus thuringiensis (Bt).
"These Bt corn hybrids have been widely adopted because they are exceptional for managing ECB -- 99.9 percent of larvae are expected to die when they feed on plants expressing Bt toxins," he said. "Yet a drawback to using these hybrids has been the high cost of purchasing the seeds, which can decrease potential profits."
To understand current ECB populations in Pennsylvania field corn, the researchers assessed larval damage in Bt and non-Bt corn hybrids at 29 sites over three years. Specifically, they planted Bt and non-Bt corn hybrids on farm sites across four growing zones in Pennsylvania in 2010, 2011 and 2012. During September of each season, they assessed corn borer damage on 400 random plants at each site. They sliced open stalks, and recorded the number of ECB tunnels and larvae per stalk. They also evaluated corn ears for ECB damage.
"Our results confirm that we are seeing widespread population declines of ECB in the East, similar to declines that have been found in the Midwestern United States," said Eric Bohnenblust, graduate student in entomology. "With less ECB damage around, non-Bt hybrids in our tests yielded just as well as Bt hybrids, so the decline in ECB populations provides an opportunity for growers to generate greater profits by planting high-yielding non-Bt seed, which is much cheaper than Bt seed. Secondarily, planting more non-Bt corn will reduce the potential for ECB to develop resistance to Bt toxins as corn rootworms have done in about a dozen states so far."
Read more at Penn State.
ECB corn feast via Shutterstock.