Released: January 10, 2002

Dry, Cold Weather Hard on Wheat

MANHATTAN, Kan. – Kansas wheat farmers know something a lot of other Kansans probably don’t – the state is suffering from abnormally dry conditions and in some areas, moderate drought.

The dry conditions, compounded by a recent cold snap, are taking a toll on the wheat crop.

Because of unusually warm weather, wheat planted last fall grew longer into the winter than usual before entering dormancy, said Kansas State University agronomist Jim Shroyer. That extended growth sapped moisture from the soil – moisture that hasn’t been replaced through snow or rainfall around much of the state.

The result of the dryness has been poor crown root development and crop growth in some areas. And the recent cold snap may have set up some wheat for winterkill.

In a report released Dec. 31, the Kansas Agricultural Statistics Service rated Kansas winter wheat 7 percent very poor, 16 percent poor, 35 percent fair, 35 percent good, and 7 percent excellent.

"The cold snap around Christmas put much of the crop into dormancy, but it was kind of a double-edged sword," said Shroyer, who is a crop production specialist with K-State Research and Extension. The quick drop in soil temperatures may have resulted in some winterkill.

Research and past experience shows that wheat can be killed or damaged when soil temperatures drop to 10 degrees F or below, Shroyer said.

Soil temperatures to a depth of 2 inches fell to 10 degrees or less at weather reporting stations near Hays and Manhattan, during the first week of January, said Mary Knapp, climatologist for the State of Kansas. Numerous stations reported temperatures in the teens.

Dry soil cools down and heats up faster than wet soil, Shroyer said.

"Are we going to have widespread winter kill? I don’t think so. Do I think there will be some? Yes," he added.

Shroyer said a good dose of moisture would help the wheat crop and would keep dry topsoil from blowing away, but it may not keep all problems at bay.

"To say a rain will cure all of our ills is not completely a valid assumption," he said. Rain or snow would help wheat root systems and would be welcome across the state.

However, last fall’s longer-than-usual growing season also left the crop vulnerable for a longer period of time to bird cherry oat aphids, which can carry the barley yellow dwarf virus into wheat plants.

"I expect to see more barley yellow dwarf this spring than we usually do," Shroyer said. Wheat streak mosaic may also be more prevalent than usual, he added.

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Mary Lou Peter, Communications Specialist
mlpeter@oznet.ksu.edu
K-State Research& Extension News