Crop Tech Corner

New Bt Cotton Protein Targets the Boll Weevil

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
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A study producing cotton plants that successfully express a Bt protein that kills the cotton boll weevil could have major implications for the pest's control in Central, South and North America. (DTN photo by Nick Scalise)

ROCKVILLE, Md. (DTN) -- This bi-monthly column condenses the latest news in the field of crop technology, research and products.


Brazilian scientists have successfully inserted a Bt protein into cotton plants to target and kill the cotton boll weevil (CBW). The boll weevil was a major cotton pest in the U.S. in the 20th century before the successful Boll Weevil Eradication Program launched in the late 1970s. However, because of weevil infestations in Mexico, the pest is not completely eradicated in parts of Texas and other parts of the southern border of the U.S. It remains a serious cotton pest in parts of Central and South America, such as Mexico and Brazil, where farmers rely on heavy insecticide use to control it.

The Brazilian researchers produced cotton plants that express a Bt protein called Cry10a in their flower buds and leaf tissue. The protein proved quite toxic to boll weevils in their test, showing "a high level of CBW mortality (up to 100%)." The study is an exciting development for South American and Central American farmers, as well as North American growers who wish to keep the boll weevil eradicated. "These Cry10Aa GM cotton plants represent a great advance in the control of the devastating CBW insect pest and can substantially impact cotton agribusiness," the scientists concluded.

See the study here:…


About 100 corn growers from the Western Corn Belt this spring will try out DuPont Pioneer's new pyramided Bt hybrids, under the brand name Qrome. The Qrome hybrids will express four Bt proteins already on the market, but with a proprietary new molecular stacking technology. Two of the proteins, Cry1F and Cry1Ab, target above-ground pests. The other two, mCry3A and Cry34/35Ab1, target the western corn rootworm. Based on company data, Pioneer is marketing the Qrome hybrids as producing a 4- to 7-bushel-per-acre yield bump over competitor's pyramided Bt corn hybrids. However, Qrome hybrids are still under stewardship and not fully commercialized yet, as the company is still awaiting Chinese import approvals.

The Bt proteins Qrome hybrids express may have reduced effectiveness in certain parts of the Corn Belt, because of Bt resistance in populations of insects such as the western corn rootworm, western bean cutworm and fall armyworm.

To read more about Qrome, see Pioneer's press release here:…

For more information on the Bt proteins in Qrome and which pests they may have reduced effectiveness against, see the Handy Bt Trait table from Michigan State University entomologist Chris DiFonzo here:


Soybeans are a billion-dollar industry in the U.S. and account for 90% of the oilseeds grown in this country today. So naturally, scientists are worried about their future -- namely, how they will react to the expected rise in global temperatures.

University of Illinois scientists are using a $420,000 grant from the National Institute for Food and Agriculture (NIFA) to explore just that question, using both crop data and computer modeling software. The researchers will use "infrared heating arrays" to expose three soybean varieties to higher temperatures, while recording their biochemical and physical growth reactions. The varieties were selected to represent the major soybean groups planted across the Midwest.

Then, the researchers will turn to the computers, said University of Illinois environmental scientist Kaiyu Guan, the project director. "We will then use the experiment results to improve and calibrate the model at the site level," he said in a university press release. "Using the calibrated model, we will attribute the historical yield loss due to increase temperature to different physiological mechanisms. Ultimately, we will project crop yield for the whole Corn Belt under the various climate scenarios, and quantify the contribution of each mechanism." Faster growth rates, shorter growing seasons, changing flower and pod production and higher water consumption are all factors expected to affect the yield of soybeans in the hotter climate, he added.

See more details from the university press release here:…

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Emily Unglesbee