New Tool for Organic Growers: PuraMaize Blocks GMO Contamination




The following is based on information provided by Blue River Hybrids.




One of the challenges organic farmers face is the potential of organic crop contamination from genetically modified crops. With ever growing numbers of GMO crops and increasing acreage being planted with GMO seed, the problems for organic producers continue to escalate.

In the 2012 publication, “GMO Contamination Prevention–What Does it Take,” Jim Riddle of the University of Minnesota Southwest Research and Outreach Center notes that “Since different types of agriculture are practiced on adjoining fields, suitable measures during planting, cultivation, harvest, transport, storage, and processing are needed in order to prevent the accidental mixing of GMO and non-GMO materials. Contamination may result from seed impurities, wind or insect-borne crosspollination, volunteer or feral plants, and/or inadequate harvest and handling practice.”

Riddle continues: “As of 2012, numerous varieties of GMO field corn have been released, with traits including herbicide resistance, insecticidal properties to kill corn borers and/or corn rootworms, and alpha-amylase to break down starch for production of ethanol. Herbicide-resistant soybeans, canola, sugar beets, alfalfa, and summer squash have been released, along with insecticidal cotton and sweet corn and disease resistant papaya. Many crops are “stacked” to contain multiple traits of herbicide resistance and insecticidal protein.”

Although there are ways to minimize potential contamination, such as the timing of planting and maintaining clear communication with neighbors, there is rising concern in the organic community about the issue.

New Option Available

PuraMaize, developed via plant breeding to create corn hybrids with the ability to resist cross fertilization by GMO pollen, is now available in organic yellow dent corn seed. An important new tool to assist organic growers, PuraMaize provides a choice for grain buyers, grain exporters, and organic livestock farmers who want assurance that their grain will be free from GMO contamination or color impurities.

The PuraMaize gene system was first developed in the late 1990s by Tom Hoegemeyer, Cerrado Natural Systems Group, while exploring ways to preserve color purity in white corn. Although ultimately another method was derived to ensure white corn’s pureness, Hoegemeyer recognized that PuraMaize could be the solution to the emerging problem with GMOs. In 2000, Hoegemeyer began breeding the PuraMaize gene into field corn using traditional plant breeding, not genetic engineering. Working with tropical varieties of corn over 10 years, Hoegemeyer brought together specific gene characteristics from obscure sources and bred out deleterious “baggage” to produce the PuraMaize gene system. Cerrado Natural Systems Group, an independent company not affiliated with any seed company, holds the PuraMaize patent, which is limited to the use of GA1S in yellow dent corn.

In 2007, Blue River Hybrids of Kelley, Iowa, secured a license to breed the PuraMaize gene system into its elite corn hybrids. Maury Johnson, an owner and founder of Blue River Hybrids recalls, “We concluded that PuraMaize would be a tremendous asset to farmers who wish to prevent GMO contamination, so we invested resources in breeding the PuraMaize gene system into hybrids that meet our standards for dependable performance in organic environments.”

Scott Johnson, Ph.D., another owner and founder of Blue River, led the effort to breed the PuraMaize gene system into Blue River’s corn hybrids, enabling Blue River to be first-to-market with three PuraMaize corn hybrids in 2012.

The Science of PuraMaize

PuraMaize is a natural gene-blocking system which impedes fertilization from GMO and blue corn pollen. It is a pollen recognition system, which strongly prefers its own pollen. When GMO or blue corn pollen drifts onto the silk of PuraMaize corn hybrids, the “foreign” pollen is quickly overtaken by the PuraMaize pollen which travels down the silk channel at a faster rate and fertilizes the ovule first. As a pollen-recognition system, PuraMaize does not affect the growth of the plant nor grain fill of the developing ear. It does not alter taste or other agronomic or functional properties.

Some varieties of tropical corn cannot be pollinated by other varieties due to the presence of one or more cross incompatibility genes. Known in corn genetics as gametophyte factors, or GaS, they selectively control fertilization by only accepting pollen from corn plants with the same genotype. Ga1S and Ga2S are two such pollen-blocking genes. PuraMaize is a gene system made up of the GA1S and other genes or gene expressions.

Farmers see PuraMaize’s Success

Blue River Hybrids has conducted several years of replicated testing of PuraMaize at 20 locations, with consistently positive and reliable results. In side-by-side field tests with GMO corn, PuraMaize either eliminates or virtually eliminates contamination.

Bred into elite Blue River corn hybrids, PuraMaize yields are competitive with similar organic hybrids. Farmers have seen the reliable yield performance they have come to expect.

Alan Ward of Viborg, Wis. has been happy with PuraMaize results in his fields: “One major challenge I faced was the delay in planting. Up until PuraMaize, I was planting at least four weeks after the conventional farmers to avoid their pollination window. That shortened my growing season and my yields. I also had trouble getting natural dry-down with such a short season. PuraMaize is a game-changer for organic farmers because it will allow us to plant how we want and when we want without the worry of GMO contamination.”

Recent GMO testing by independent agency Genetic ID of Fairfield, Iowa, rated farmer PuraMaize samples as “GMO Not Detected, negative at the operational limit of 0.05%.” This affirms that PuraMaize performs as expected, making it possible for the organic farmer to grow a GMO-free crop.

Although PuraMaize is confirmed to prevent contamination, it is not, however, a silver bullet. PuraMaize cannot stop pollen movement, but it can block successful fertilization by non-PuraMaize pollen. Farmers still have to clean out and monitor all equipment used for planting, harvesting, and hauling grain. For more information on other ways to reduce GMO contamination, refer to “GMO Contamination Prevention- What Does it Take?”

Organic Certification

PuraMaize has been reviewed and approved for organic use by OCIA of Lincoln, Neb., the organic certifier for Blue River Hybrids. Blue River Hybrids currently offers three PuraMaize hybrids. 58PM36 is USDA certified organic. 47PM36cnv and 71PM50cnv are provided as conventional untreated seed, approved for use on organic farms under the NOP provision that an organic equivalent is not available. Plans are being made to offer organic 71PM50 for the 2014 growing season.

To learn more about PuraMaize including information on summer field days and conference workshops, visit or call the Blue River Hybrids office 800-370-7979.

PuraMaize is a registered trademark of Cerrado Natural Systems Group, Inc., of Hooper, Neb.

May/June 2013

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