Released: August 07, 2007

Wheat Test Weight or Variety: Which is More Important this Year?

MANHATTAN, Kan. – Many wheat producers in central and eastern Kansas are facing a dilemma this summer: Is it better to buy low-test-weight certified seed of a variety

well adapted to their area, or high-test-weight certified seed of a variety that is not well adapted to their area?

The first criterion producers in central and eastern Kansas should consider is whether the variety they buy is resistant to soil-borne mosaic, said Jim Shroyer, agronomy state leader for K-State Research and Extension.

“Many of the varieties grown widely in western Kansas do not have soil-borne mosaic resistance. Producers in central and eastern Kansas would be putting their wheat crop at risk of getting soil-borne mosaic by planting these varieties,” he explained.

But some varieties grown in western Kansas are resistant to soil-borne mosaic, he added.

“The problem is, some of these varieties are quite susceptible to leaf rust and powdery mildew, and have not performed especially well in central and eastern Kansas in recent years,” Shroyer said. “Newer varieties have performed well in central and eastern Kansas, and have better leaf disease resistance. But most of these varieties are not grown on many acres in western Kansas yet, and there won’t be a good supply of high quality certified seed of those varieties available this fall.”

Variety selection isn’t the only consideration. Seed quality also has to be considered, the agronomist said. “It has been documented that wheat with a test weight below 54 to 56 pounds per acre may have lower yield potential, and less seedling vigor, than higher-test-weight seed. It is understandable that producers would want to plant seed with a test weight of 58 pounds or higher if possible,” he said.

If producers in central and eastern Kansas are faced with a decision of whether to buy low-test-weight seed of a variety with soil-borne mosaic resistance or high-test-weight seed of a variety susceptible to soil-borne mosaic, the best choice would be to buy seed of the variety with soil-borne mosaic resistance, Shroyer said.

“It is critical to select a variety adapted to the area where it will be planted,” he said. “That is by far the most important criterion. As long as a variety is adapted to the area, then seed quality is the next most important criterion.”

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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:
Steve Watson,
swatson@ksu.edu
K-State Research& Extension News