In Texas, water is gold.
Germplasm and stay-green technology from Texas AgriLife Research corn breeders could mean growing corn on limited water soon.
Thomas Marek, AgriLife Research irrigation engineer and superintendent of the North Plains Research Field near Etter, walked through fields of corn last season that showed a stark contrast between existing commercial corn varieties and experimental germplasm developed by Wenwei Xu, AgriLife Research corn breeder in Lubbock.
In a study designed to pump only 12 inches of irrigation to supplement whatever Mother Natured provided and still grow 200 bushels of corn per acre, year 2011 certainly demonstrated the extreme differences irrigation and germplasm can make on a crop.
Marek says it also showed the production risks and costs associated with potential limits on irrigation water for a high water-use crop.
“This was an extremely dry year as we had no soil moisture. And we only received a little over 2 inches of total rain during the entire growing season, with most coming too late to help production,” he notes. “We were expecting on average a 10-inch contribution.
“Our irrigation goal with the project was to get the corn crop up, manage the limited irrigation water to pollination, and then let the ‘rainfall chips’ fall where they may with the three varieties,” Marek says.
No ears by full ears
The plots were 12 rows wide, 300 feet long, with four replications each at four-plant populations.
Within the commercial varieties in the extremely dry year, some individual corn plants had no ears or relatively small ears.
However, growing right next to these corn varieties—under the same conditions—was an experimental variety being developed by Xu that had nearly full ears, Marek reports.
Marek says the difference is in the germplasm and stay-green, which is a drought-resistance trait.
“There’s a marked difference in the stress conditions of these commercial corn plots versus the experimental varieties,” he says.
The experimental germplasm variety had a pretty good sized ear on the corn plants, and the plants exhibited good turgor pressure or plant strength, Marek says. In fact, the experimental variety that had not been irrigated in a month “still looked strong and green” this past September, while commercial varieties were beginning to dry out.
“It was apparent the commercial varieties were severely stressed, more so than the experimental variety,” he says. “These types of germplasm being developed by Dr. Wenwei Xu will be integrated into the commercial varieties through the corporate commercial companies’ breeding programs. The desired traits that are being derived through the AgriLife Research corn breeding program will be integrated into those new proposed varieties.”
Marek says germplasm alone won’t be enough to sustain a corn crop through a summer like the one of the past season. Even in wetter years, greater production with fewer inputs, are going to be required to feed the increasing population of the world.
“The irrigation management or scheduling plays a vital role, up to 50 to 60 percent,” he says. “It’s paramount to get the combination of irrigation and genetics correct to achieve these types of production levels.”
The corn research project is jointly sponsored by the North Plains Groundwater District and the Ogallala Aquifer program.
“These particular germplasms show extreme promise,” Marek says. “But it’s a synergistic effect where you need both genetics and irrigation management if you are going to derive the potential of the new variety going forward, especially in the extreme and limited water conditions, which are prevalent throughout the Great Plains region.”
--Ledbetter is with Texas A&M Communications, Amarillo.