sealPurdue News

November 4, 2002

Field of extremes: Purdue corn trial yields widely varied

WEST LAFAYETTE, Ind. – Purdue University agronomists can sympathize with Indiana corn growers. The same delayed planting schedules, isolated showers and drought-induced yield losses that did a number on farmers' corn crops this year also shaped agronomists' test plots.

As a result, Purdue's annual corn performance trials produced crops that ran the gamut from fair to excellent. The data – diverse as it is – should help farmers better select dent corn hybrids best suited for them in 2003, said Phil DeVillez, Purdue agronomist and field trial coordinator.

Preliminary field trial results are available online. The full report will appear on the Web and in print form later this month.

The 2002 trials tested approximately 150 conventional and Bt hybrid varieties, representing about 40 large and small seed corn companies. Trials were conducted at 13 locations across the state, including Purdue research farms and on land owned by cooperating farmers.

Excessive spring rain pushed test plot planting to May 5, with the last plots seeded on June 3, DeVillez said. Except for a few plots, harvest was completed by Oct. 20. In between planting and harvest, conditions were mostly dry.

While yields overall were down from the 2001 trials, many plots did better than expected, DeVillez said.

"We were pleasantly surprised with some of the yields," he said. "Even in the locations where they didn't get much rain it seemed like we had decent yields.

"Yields ranged from over 200 bushels per acre in some locations – with test averages of 170 bushels or so – down to around 100 bushels per acre. Some of our higher yields were at the West Lafayette, Cloverdale and Washington, Ind., locations. Some of the lower yields were at the Pinney-Purdue farm, which is in northwest Indiana near Wanatah, and the northern region in general."

Hybrid performance depended more on location and rainfall than other factors this year, DeVillez said. In some cases, the same hybrid variety that produced good yields in one location produced poor yields in another. Crop diseases and insect problems were few, he said.

"At the dry locations we did see some incomplete fertilization of the ears, sporadic kernels on the cobs and things like that," he said. "Leaf diseases were relatively low this year, simply because of the lack of rainfall. Many diseases need rainfall to get going."

Test weights at the 13 trial locations varied from 51.3 pounds per bushel to 56.4 pounds per bushel, with moisture levels coming in between 16.9 percent and 27.6 percent. Plant lodging was as low as zero percent and as high as 17 percent. Stands were consistently in the upper 80 percent to mid-90 percent range.

Field tests were conducted uniformly at each location. Hybrid varieties were planted in four-row plots, with only the middle two rows counted toward test data. Common fertilization and tillage practices were used. Similar maturing varieties were tested together to ensure fair comparisons.

Participation in the performance trials is voluntary. Seed companies provide Purdue agronomists with seed corn. About 10 percent of the hybrids tested this year were Bt varieties, DeVillez said.

In addition to releasing 2002 test results, agronomists are preparing two-year trial summaries for the 2001-02 crop years.

"We strongly recommend that people look at the two-year summaries, because you have hybrids that did well last year and this year, but it's a pretty short list," DeVillez said. "We had two extremely different years weatherwise. When you have years like that it makes hybrid selection a little easier, because you have fewer hybrids that are still at the top of the test."

Copies of Purdue's field test report, Agronomy Bulletin B-816, "Performance of Commercial Dent Hybrids in Indiana 2002," will be available at county offices of Purdue Extension by Thanksgiving.

Writer: Steve Leer, (765) 494-8415,

Source: Phil DeVillez, (765) 494-0406,

Ag Communications: (765) 494-2722; Beth Forbes,;

Related Web site:
Purdue University Department of Agronomy

Purdue News Service: (765) 494-2096;

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