How social science helps keep bugs off corn

A new study suggests broad systemic problems play a significant role in disincentivizing corn growers from planting the refuge corn needed to keep pests from becoming resistant to the insect-killing traits in Bt corn. And social science can play a role in addressing this challenge. The paper, “Moving beyond grower compliance: why Bt corn resistance management depends on system-level coordination,” is published in the Journal of Economic Entomology.

Insect-resistant corn, known as Bt corn, is created by genetically modifying corn seeds to produce a bacteria (Bacillus thuringiensis) toxin, which kills common pests like caterpillars or beetles. To prevent these pests from evolving resistance to Bt corn, farmers are required by seed producers to plant a small area of land with “refuge” corn, which does not include the Bt toxin.

However, planting refuge corn is influenced by more than individual grower choice. Economic incentives, seed availability, and how refuge requirements are implemented can all shape decisions. In some cases, growers may perceive refuge corn as carrying greater risk or lower returns, which can discourage its use.

This presents a problem because the refuge system only functions if all the growers in an area participate. Getting growers to do so may require expertise outside of physical and life sciences, said Dominic Reisig, professor and extension specialist at North Carolina State University and co-author of a paper on the study.

“When we think about policies that impact growers, we need to incorporate people from the social sciences,” Reisig said. “Oftentimes, we’re just thinking about the grower, and placing all the responsibility there, instead of looking at the system that creates incentives for them to make the choices that they make. What we’ve found is that social science experts recognize the importance of that system right away, and that’s a valuable perspective to have.”

While corn growers are ultimately responsible for putting refuge corn seed in the ground, Reisig said there are several points of tension throughout the corn production pipeline that effectively encourage growers not to plant refuge corn. These include a lack of high-yielding non-Bt corn seed, weak regulatory enforcement, and low incentives for the seed industry to prioritize the sale of refuge corn.

A United States Environmental Protection Agency proposal requiring growers to purchase refuge corn alongside Bt corn seed at point of sale is a step in the right direction, Reisig said, but still places too much emphasis on corn growers as the primary, and perhaps only, factor in determining the success of refuge planting. The seed industry also takes about five years to get a new breed to market, he said, which makes quickly implementing new refuge requirements difficult.

By integrating social scientists into agricultural policy decisions, pain points throughout the system could be identified faster and resolved in a way that spreads out accountability, Reisig said.

“What we have is a situation where many actors are all making decisions that appear correct and make sense for their own needs, but when strung together create a system that doesn’t accomplish its goal,” he said. “Hard-science agricultural researchers may not always see that, but a social scientist can take one look and say, ‘of course it’s the system.'”

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Gaby Clark

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