2007 Ohio Corn Performance Test

R.J. Minyo Jr.¹,  A.B. Geyer¹, P.R. Thomison¹, B.L. Bishop², and D.G. Lohnes²

Ohio Corn Performance Test, ¹Department of Horticulture and Crop Science and ²Computing & Statistical Services, The Ohio State University, Ohio Agricultural Research and Development Center.

TEST LOCATIONS

The purpose of the Ohio Corn Performance Test is to evaluate corn hybrids for yield, grain quality, and other important agronomic characteristics. Results of the test can assist farmers in selecting hybrids best suited to their farming operations and production environments. Corn hybrids differ considerably in yield potential, standability, maturity, and other agronomic characteristics that affect profitable crop production. Hybrid selection should be based on proven performance from multiple test locations and years. The presentation of data does not imply endorsement of any hybrid by The Ohio State University.

EVALUATION PROCEDURES

Seed companies marketing corn hybrids in Ohio were invited to enter hybrids in the test. An entry fee was charged to cover expenses. Companies were permitted to enter an unlimited number of hybrids. Ten sites were available for hybrid evaluation. Testing was available in three regions of Ohio (Southwestern and West Central; Northwestern; North Central and Northeastern). Companies were required to enter a hybrid in three sites within a testing region. Testing was also conducted at Coshocton (east central Ohio) in an area of high gray leaf spot incidence. Evaluation techniques for hybrids at this location were similar to those used in the regional testing program. Each hybrid entry in the regional trials is evaluated using three replications per site in a randomized complete block design. In the regional tests, hybrids were planted either in an early or full season maturity trial based on relative maturity information provided by the companies. In the Southwestern and West Central region, the relative maturity of hybrid entries in the early maturity trial was 110 days or earlier; the relative maturity of hybrid entries in the full season trial was 111 days or later. In the Northwestern and North Central and Northeastern regions, the relative maturity of hybrid entries in the early maturity trial was 108 days or earlier; the relative maturity of hybrid entries in the full season trial was 109 days or later. At Coshocton, four replications were used and hybrids were not evaluated separately by maturity.  

Hybrids were planted with a commercial type planter adapted for plot planting. Each plot consisted of four 30-inch rows approximately 25 feet long. Seed corn producers selected a final stand and percent overplant for each hybrid entered. Fertilizer, herbicides and insecticides were applied according to recommended cultural practices for obtaining optimum grain yields. Details concerning the establishment and management of each 2007 test are listed in footnotes below the tables.

MEASUREMENTS AND RECORDS

YIELD. The center two rows of each plot were harvested with a self propelled two row picker sheller combine. Yields were reported as bushels of grain per acre (BU/A) at 15.5 percent moisture.

MOISTURE (HARV MST). A grain moisture determination was made from each plot with an electrical conductance moisture meter. Grain moisture was reported as percent grain moisture.

LODGING (STK LDG). The number of broken stalks in each plot was determined just prior to harvest. Only those plants with a stalk broken below the ear were considered stalk lodged. Stalk lodging was reported as a percentage of final plant stand.

FINAL STAND (FINAL STD). Seed corn producers selected a desired planting rate for each hybrid entered. Differences between the planting rate and the final stand may be attributed to seed quality and/or environmental conditions present. Populations were reported in hundreds (100/A) per acre.

EMERGENCE (EMG). An emergence count was made on each plot after plant emergence. The emergence percentage was computed based on the number of plants and the number of kernels planted, and was reported as a percentage of the kernels planted.

MID SILK (SILK). The mid silk date is the Julian day of the year in which 50% of the plants show silks at one site in a region.

TEST WEIGHT (TW). Test weights were recorded in pounds per bushel on grain samples at field moisture. The results are an average of all three sites in the regional tests.

PROTEIN - OIL - STARCH (PROT-OIL-STRCH). An analysis for crude protein, oil, and starch was performed on dried samples by the OSU Grain Quality Laboratory using a near‑infrared transmittance whole grain analyzer with a SystemOne program calibration. Results are reported as percent protein, oil, and starch content at 15.0 percent grain moisture.

LSD 0.05 - Least Significant Differences at probability level 0.05 (LSD 0.05) are reported for yield and other agronomic characteristics. Differences between hybrids are significant only if they are equal to or greater than the LSD value. If a given hybrid out yields another hybrid by as much or more than the LSD value, then we are 95% confident (i.e. the odds are 19:1) that the yield difference is real, with only a 5% probability that the difference is due to chance variation (such as soil variation, etc.). For example, if Hybrid X is 19 Bu/A higher in yield than Hybrid Y, then this difference is statistically significant if the LSD is 19 Bu/A or less. If the LSD is 20 Bu/A or greater, then we are less confident that Hybrid X really is higher yielding than Hybrid Y under conditions of the test. If 'NS' is indicated for a characteristic, then the differences among hybrid entries are not significant at the 5% probability level.

GROSS INCOME IN $/ACRE. Calculated using corn price of $3.5 per bushel and $0.04 drying charge for each percentage of moisture above 15.5%.

2007 GROWING CONDITIONS

Environmental conditions varied greatly across Ohio during the 2007 growing season, especially with regard to the amount and distribution of precipitation. Temperatures were above normal and rainfall below normal at planting. These warm, dry conditions promoted crop establishment and root development. Warm, dry weather persisted through maturity at the test locations near S. Charleston and Washington CH in SW Ohio. However, drought stress damage was averted by timely rains. Rainfall deficits at the other test sites were alleviated by above average rainfall in August. Rainfall accumulation was 7 to 8 inches above normal at NW test sites and 1 to 2 above normal at NE sites. Hot, dry conditions in September and October resulted in rapid grain drydown and unusually low grain moisture at harvest at several locations. Despite periods of drought stress, stalk quality was excellent and stalk lodging negligible across locations. Disease and insect pests were not a significant factor at test sites.

RESULTS

Confidence in test results increases with the number of years and the number of locations in which the hybrid was tested. Data from a single test site should be avoided, especially if the site was characterized by abnormal growing conditions. Look for consistency in a hybrid's performance across a range of environmental conditions. Grain moisture percentage at harvest can provide a basis for comparing hybrid maturity, especially when grain moisture levels average above 20% at a test site. Yield, standability, test weight, and other comparisons should be made between hybrids of similar maturity to determine those best adapted to your farm. Since environmental conditions affect grain composition, the values reported for protein, oil, and starch should be used for comparison purposes and not as absolute values for feeding.

Acknowlegements

We thank our farmer cooperators for their contributions to the 2007 corn hybrid testing program. We are grateful for the assistance provided by Clarence Renk and Joe Davlin, OARDC Western Agricultural Research Station, Lynn Ault, OARDC Wooster, Matt Davis, OARDC Northwest Agricultural Research Station, Jim Rich, FFA/Riverview High School, Gary Prill and Andy Kleinschmidt, OSU-Van Wert Co. Extension, Adam Shepard, HCS graduate associate, Steve Prochaska, OSU- Crawford Co. Extension. We thank Tim Bowman in Communications and Technology for his assistance in preparing the test results for publication.

11/2007
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