Plant breeders say new drought-hardy corn testing well in U.S.

* Developers of drought-hardy corn see broad expansion

* More research needed on high heat impact on plants

* Results still early, but encouraging, developers say

Sept 18 (Reuters) - Corn seed developers who have been racing to build better varieties for low rainfall and high heat say results have been encouraging despite the worst U.S. drought in half a century.

Triple-digit temperatures (Fahrenheit) coupled with historically dry conditions ravaged farm fields across the nation, with some of the most severe conditions gripping the top U.S. corn growing states in the Midwest and Plains states.

In some of the driest growing areas, virtually all of the corn crops failed, drought-tolerant or not. Still, those companies rolling out corn designed specifically to grow well in drought have been reporting better-than-expected results.

“This is a really great year to validate that research work,” said Jeff Schussler, senior research manager in maize stress product development at Pioneer Hi-Bred International, a unit of DuPont and a top global corn seed producer.

He said Pioneer’s “Optimum Aquamax” corn was “inhibited” by the extent of this year’s drought but confirmed expectations.

“It has to have water to grow. But we’re showing some stability,” Schussler said. “We don’t have nearly all the data in yet. So far seen everything we’ve seen has been very positive.”

Duan Martin, Syngenta AG’s product lead for its version of a drought-hardy corn, Agrisure Artesian, echoed that assessment.

“A percentage of our fields did not make an acceptable crop, but in most cases where water was enough to make a crop, we saw it out-perform those hybrids without the trait,” said Martin.

The U.S. Department of Agriculture estimates U.S. farmers will harvest 10.7 billion bushels of corn this year, the smallest crop in six years. Farmers are expected to see an average yield of only 122.8 bushels per acre, the lowest since 1995 and the third straight year of falling corn yields, largely tied to drought.

Plant breeders say final data will be in within the next six weeks as harvest wraps up. But so far, test plot yields and farmer harvest reports are encouraging enough that seed sales for next season should expand dramatically, both in the western corn belt, and into eastern areas of the Midwest, where drought tolerance once was not seen as a big need.

“No technology will replace all the yield lost to drought. “But at $8 per bushel this is very significant money to a grower,” Martin said.

Syngenta’s corn, introduced in 2010, has been engineered - though not through transgenic modification - to deliver 15 percent yield preservation under drought stress. This year, the corn met or exceeded those expectations, said Martin.

The company sold seed for about 15,000 acres (6,070 hectares) to growers for this season. Seed sales are kicking off now for spring planting in 2013 and Syngenta is pegging sales of seed for 400,000 acres.

Sales will be expanded east in Ohio and north into Minnesota, not typically areas where drought is considered a significant problem.

“This is not technology that is limited to the western corn belt where drought occurs regularly. This is technology that applies across the corn belt. This is something we’ve believed quite some time and the 2012 drought confirmed it for us,” Martin said.

Pioneer provided seed for about 2.5 million acres in 2012, and plans for an “aggressive” expansion of seed sales for the 2013 planting season. The company is currently identifying which hybrids can be expanded in central and eastern corn belt and into the deep south, Schussler said.

Pioneer is also establishing additional research sites in the southern U.S. to intensify its research on how to improve corn performance in persistent high heat like seen this summer.

“One of the things we’ve learned this year is the additional value of heat tolerance in addition to drought tolerance. Heat definitely makes the stress much worse,” Schussler said. “We need to be prepared for more extreme weather years.”

Global biotech seed developer Monsanto is launching commercial sales of its licensed genetically modified Genuity “DroughtGard” hybrids for the 2013 growing season after testing the corn with 250 farmers this summer. Some farmers were finding a 6 bushel per acre advantage over other hybrids, Monsanto officials said.

For Kansas farmer Clay Scott, one of the farmers testing Monsanto’s corn, the experimental varieties yielded about 10-15 bushels above the plot average.

“Those are not huge amounts but still pretty exciting,” said Scott, who also grows wheat and raises cattle. “This was a tough year.”