When it comes down to a bag of corn seed, there are hard-to-control factors during storage: temperature and moisture. With a bad combination of the two, an infestation of insects or mold could happen and could cause mycotoxin contamination. However, a recent study at the Iowa State University Seed Science Center (ISU SSC) showed farmers planting Bt corn didn’t have the same problems with insects and mold in storage compared to those who planted non-Bt corn.
Bt corn is enhanced through biotechnology to protect crops in the field from insect pests, however, researchers discovered it also works post-harvest in storage, according to the release. Though researchers already knew Bt corn was resistant in storage against the Indianmeal moth, it’s also resistant to the maize weevil. In addition, the study conducted by Julie Mandap, Richard Hellmich and Gary Munkvold, proved Bt corn was 100% effective against insects in the stored grain.
“The Bt resistance was developed specifically for field pests like European corn borer and corn rootworm. Previously it’s been shown that in the field, Bt insect resistance also helps protect against fungal infection and mycotoxins,” said Gary Munkvold, a professor at the ISU SSC. “There have been some studies on Bt resistance to storage insects but not with the added element of the storage molds. Also, those studies only included moth larvae. Showing resistance to weevils is new.”
Though most corn grown in the U.S. already has a Bt trait in it, ISU SSC says this can help particularly for farmers in developing nations, who typically resort to using insecticides to protect their crops.
“Farmers in developing countries, where they are not currently growing Bt corn, have more problems with stored corn because of the climate and the lack of climate-controlled storage facilities,” Munkvold said. “The Bt corn is safe, and it provides yield stability and higher quality, safer grain when there is insect pressure, and allows farmers to avoid the hazards of applying insecticides.”
