Etter, Texas
August 22, 2008
At the end of the day, drought
tolerance in corn has to equate to good yields and good quality,
not just good looks, said a
Texas AgriLife
Research scientist.
Dr. Wenwei Xu, AgriLife Research corn breeder from Lubbock, is
working with crosses between temperate and tropically adapted
varieties of corn to find a drought-tolerant plant that performs
well under reduced irrigation.
“With the continuing decline of the Ogallala Aquifer water level
and increasing cost of pumping water, the use of
drought-tolerant and high-yield corn hybrids is a key for
sustainable corn production under limited irrigation,” Xu said.
A field day was held recently at the North Plains AgriLife
Research Station near Etter to demonstrate the differences
between the parent plants and the offspring, or crosses.
“We hope to reduce the amount of water required for corn by at
least 10 percent,” Xu said.
Already the AgriLife Research program out of Lubbock has
released four inbred lines of corn and numerous others are in
the process for release, he said.
“The new multiple-stress-tolerant corn lines can be used to
produce corn hybrids adapted to Texas and other southern
states,” Xu said. “They can be a powerful tool to save water and
produce crops with yield and grain quality under stressful
environments.”
The research station at Etter is one of three test sites in Xu’s
program. The others are located at Halfway and Lubbock.
About 500 hybrids are being evaluated this year for either grain
yield or silage yield and quality, he said.
Xu said there has been an increasing demand for silage corn in
the Texas High Plains, and producers need new hybrids adapted to
the local environment. Corn produced in the U.S. is primarily
based on two races of maize, but there are more than 250 races
identified around the world, Xu said.
“Most of our breeding efforts start by crossing tropical corn
with temperate elite lines,” he said. “Then we select for
desirable traits to broaden genetic diversity and introduce
useful genes from exotic corn to improve stress tolerance,
agronomic productivity, disease resistance, insect resistance
and value-added grain characteristics.”
Xu said some of the experimental hybrids they are working with
have produced the same silage yield under irrigation equaling 75
percent evapotranspiration as with 100 percent
evapotranspiration irrigation.
Evapotranspiration is the loss of water from the soil both by
evaporation and by transpiration from the plants, and is
reported on a daily basis through the Texas High Plains
Evapotranspiration Network
(
http://txhighplainset.tamu.edu/).
Bruce Spinhirne, AgriLife Research associate based in Lubbock,
said they reduced the irrigation on a few hybrids by 50 percent
and had a severe yield and quality limitation, so they followed
that by the 75 percent water application.
Those results are due in part to the use of stored moisture in
the soil profile, Spinhirne said.
“At 75 percent (evapotranspiration), you have 3 to 4 inches of
available moisture that is used, where if you are watering at
100 percent, it is wasted,” he said.
The average silage yield of 20 corn hybrids at two locations
(Etter and Halfway) was 26.84 tons per acre under 75 percent
evapotranspiration irrigation, just slightly lower than the
27.49 tons per acre under 100 percent evapotranpiration
irrigation, Spinhirne said.
However, he said, there were significant differences among
hybrids in each environment.
“One of our experimental hybrids produced the same amount of
silage in both locations when irrigation was reduced from 100
percent to 75 percent,” Spinhirne said.
“Developing and using new corn hybrids with improved tolerance
to drought and other stresses is important and a viable
water-saving approach,” he said.
More information on the corn and silage trials can be found at
http://lubbock.tamu.edu/corn . |
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