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Corn Variety Research for the Organic Farmer

By Tina Wright




Dr. Margaret Smith, plant breeder at Cornell University, discusses corn varieties at an organic open house in September 2013.
Photo by Tina Wright.

Looking ahead seven generations is a Native American way of weighing decisions in the here and now for impact in the future. Margaret Smith, a plant breeder at Cornell University who focuses on corn, says that it takes seven generations to test a corn strain in the field. To pack two generations into a single year and accelerate the process, Cornell researchers collect corn seed from test plants in the fall and send those seeds to an organically certified winter nursery and fields in Puerto Rico for a winter crop.

Why research organic corn varieties? Smith, who serves as the associate director of Cornell's Agricultural Experiment Station, says, "Organic production systems are different from conventional." Organic corn is often planted later than in conventional systems, sometimes following a cover crop, and almost all organic corn is "first-year corn," planted on a field that did not have corn the previous year. Nutrient availability for plants can differ in organic systems. Compost and natural fertilizers provide "slow-release" nutrition to plants compared to conventional farming.

Controlling weeds through cultivation rather than herbicide applications can physically stress corn plants, and the arrangement of corn leaves may influence the time it takes for the canopy effect that shades out new weeds. "For organic corn growing, you want a leaf canopy to close as soon as possible," explains Smith.



Organic corn trials at Cornell's Homer C. Thompson Vegetable Research Farm in Freeville, N.Y.
Photo by Tina Wright.

Going after these desired traits may result in varieties that work best for organic growers, but Smith says, "We won't know until we actually have these varieties." It's like a pipeline - many possible new corn varieties are tried out every year, and the varieties in later stages of testing get narrowed down. In 2013, Smith and her colleagues grew around 20 potential new varieties in two locations, a batch of varieties in the middle stages and a handful in the last stages, with around 40 total, including open-pollinated varieties.

"Most aren't good enough," Smith says. "We have to try a lot of stuff." Testing varieties for many years in different locations means that the performance of "one-year wonders" is put to the test. The plant breeder says, "It takes multiple years to convince yourself that it's a predictable genetic performance."

In 2011, Blue River Hybrids, an organic seed company in Kelley, Iowa, bought D2901, a corn strain developed from Cornell's program, and sold it for one season. Lakeview Organic Grain in Penn Yan, N.Y., still sells the seed, which is described as a workhorse corn, rather than a racehorse. It will never have the highest yields, but it's reliable, even in tough field conditions. Smith explains that D2901 is a variety with four parents; it's a double cross of two hybrids, which gives it the ability to grow big, vigorous plants.

In the field

At the University of Vermont, Dr. Heather Darby, extension agronomist, leads a team trying out commercially available organic silage corn varieties. In the 2013 Vermont Organic Silage Corn Performance Trial Results (http://bit.ly/1cQrh1k), the team reports, "The 2013 growing season was a challenging season for corn production, and hence the results were less than favorable. However, varieties that were able to thrive in these adverse conditions would likely be varieties that could produce well in a variety of conditions."



A cornfield with the hybrid D2901 developed by Cornell and released commercially in 2011. Some rows have been detassled to ensure they are pollinated by the other parent of the hybrid and to create hybrid seed for organic growers.
Photo courtesy of Cornell University.

For corn that's desirable for organic production, Darby lists many of the same traits as her colleague at Cornell: early varieties, good early-season vigor, disease resistance and nutrient uptake efficiency.

"It's a niche market for sure," she says, "but there are many organic growers and markets, so there is a demand." Organic farmers want more available varieties. According to Darby, organic silage corn yields generally average 18 tons per acre in her area of Vermont, but the challenges of the weather in 2013 brought in 14 tons per acre. For 2014, the Vermont group will conduct two organic corn trials in northern and central Vermont.

The UVM trial results state: "Crop performance from additional tests in different locations and over several years should be compared before making varietal selections."

They invited several seed companies and farmers to submit seed for evaluation. Those who submitted corn seed include: Blue River Hybrids/Boucher Fertilizer, Highgate Center, Vt.; Lakeview Organic Grain; Albert Lea Seed, Albert Lea, Minn.; and American Organic, Warren, Ill.

June 2013 saw monsoon-level rain in Vermont. Some corn plots were flooded, and mechanical cultivation was delayed. "Interestingly, there were still several varieties that were able to produce exceptional yields even under severe weed pressure. These varieties ranged from 77 to 104 days for relative maturity. Varieties that have a high level of early-season vigor and compete well against weeds and other stresses will be highly advantageous to organic farmers," according to the trial results.



Dr. Margaret Smith and Klaas Martens evaluate corn at Lakeview Organic Grain, his farm in Penn Yan, N.Y., which is participating in Cornell's organic corn trials.
Photo courtesy of Cornell University.

The big picture

One funding source for this organic corn research has been the USDA's Agricultural Research Service. Just like Smith and her colleagues are doing at Cornell, other breeders are developing corn varieties for their regions. Marvin Scott, Iowa State University, heads up the effort that includes the Southwest, Upper Midwest, the eastern Corn Belt and the Northeast. The research project's goal is "strengthening public corn breeding to ensure that organic farmers have access to elite cultivars." The project began in spring 2011 and is scheduled to wrap up this fall.

Smith likes to work in the field, and her connection with Bryan Brunner, a horticultural researcher at the University of Puerto Rico, was a fortunate one. The organically certified greenhouse and farm plots work out perfectly to accelerate her corn breeding program. "I have corn growing there right now," she said in February, and one of her graduate students was heading down to do pollination work.

The author is a freelance contributor based near Ithaca, N.Y., specializing in dairy and organics, but dabbling in all things agricultural. Comment or question? Visit http://www.farmingforumsite.com and join in the discussions.