2007 U of M corn hybrid performance trial report is available

By David Nicolai and Thomas R. Hoverstad, University of Minnesota Extension

Results of the Minnesota Corn Hybrid Evaluation Program are now available on the internet at http://sroc.coafes.umn.edu/. The corn yield trials were conducted by the University of Minnesota Agricultural Experiment Station to provide unbiased information for use by corn growers when they choose hybrids to buy and grow. The program was financed in part by entry fees from private seed companies that chose to enter their hybrids for testing. A paper copy (Varietal Trials) of these trials will be available at local County Extension offices in late December.

Corn variety testing is conducted on multiple test locations: Test zones, locations and maturities are as follows:

Southern zone: Lamberton, Waseca, and Plainview; Early Maturity Trial — 103 relative maturity and earlier hybrids; Late Maturity Trial — 104 relative maturity and later hybrids.

Central Zone: Morris and Rosemount; Early Maturity Trial — 95 relative maturity and earlier hybrids; Late Maturity Trial — 96 relative maturity and later hybrids.

Northern Zone: Staples, Rothsay and Crookston.

The benefit of multiple testing locations in a single year is that they represent possible weather patterns an individual farm may encounter in the future. Weather variability influences hybrid performance more than any other variable, because weather interacts with most of the other yield-limiting factors. If a hybrid performs consistently well over many sites (i.e., weather patterns), then it will likely perform well on your farm in the future.

Testing procedure used in 2007:

Each seed corn company (35 companies participated in 2007) could enter up to six hybrids per zone. Entries in each replicated trial were based on the relative maturity provided by the company. The University of Minnesota Corn Testing Committee could also choose and enter hybrids in each test. For this reason, there may be more than six hybrids for a company in a test.

Presentation of plot data results:

Yields are given for individual locations along with yields and harvest moisture contents averaged across locations for 2007. Reported yields are adjusted to 15.5 percent grain moisture. Hybrids are ranked within maturity group by moisture content averaged across locations for 2007. A statistical formula called least significant difference is used to help growers determine when real differences occur between hybrids. The least significant difference is a number at the bottom of the yield columns in the tables which is a statistical measure of variability in the trials. These numerical values may be used to determine whether the difference between any two hybrids is likely to be a real difference or just natural variation.

If the yield difference between two hybrids is equal to or greater than the least significant difference, then one can be confident that the two hybrids probably differ in yield potential. We show least significant difference values with a 0.2 alpha level which means that when two hybrids differ in yield by the least significant difference value or more, one can be 80 percent confident that the two hybrids differ in yield potential. The higher yielding one is the better hybrid from the yield standpoint. If the yield difference between two hybrids is less than the least significant difference, the two hybrids probably do not differ significantly in yield potential.

(David Nicolai is a crops Extension educator with University of Minnesota Regional Extension in Hutchinson. Thomas R. Hoverstad is a scientist with the University of Minnesota Extension Southern Research and Outreach Center in Waseca.)