R.J. Minyo Jr.1, A.B. Geyer1, P.R. Thomison1, B.L. Bishop2, and D.G. Lohnes3
Ohio Corn Performance Test, 1Department of Horticulture and Crop Science, 2Computing & Statistical Services, and 3Communications & Technology, The Ohio State University, Ohio Agricultural Research and Development Center.
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.
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. Eleven 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 two other sites, Piketon (southern Ohio) and Coshocton (east central Ohio), that are in areas known to contain a high incidence of corn virus and gray leaf spot, respectively. Evaluation techniques for these hybrids were the same as those used in the regional testing program.
Each hybrid entry in the regional trials was evaluated using three replications per site in a randomized complete block design. At Piketon and Coshocton, four replications were used. 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 111 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/ 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.
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 2001 test are listed in footnotes below the tables.
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 a 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 calendar 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.
Environmental conditions varied greatly across Ohio during the 2001 growing season, especially with regard to the amount and distribution of precipitation. Conditions in late April and early May were generally dry and favorable for planting, but shortly thereafter, corn was subjected to three to four weeks of cool, wet weather which resulted in restricted, shallow root systems and loss of nitrogen (N) through denitrification and leaching. This protracted period of adverse growing conditions coincided with the germination and emergence stages for corn in test plots.
Rainfall in the Southwestern and West Central region was above normal and well distributed throughout the growing season. However, rainfall at sites in northern Ohio, especially the Northeastern region, was sharply below average. The test sites in the Northeastern region received 10 inches less precipitation than sites in Southwestern and West Central region.
Above normal rainfall at the Southwestern and West Central sites during flowering and grain filling promoted high yields, but heavier ears put greater stress on plants with poor root systems, and predisposed corn to stalk rot and stalk quality problems as the crop was maturing. In many cases, plants cannibalized tissues in the lower stalks to provide nutrients to fill the grain. The precipitation and temperatures in October were near ideal for stalk rots. These conditions resulted in extensive lodging of some hybrids in the Southwestern and West Central region. Lodging damage was magnified by strong winds associated with thunderstorms in late October. Conditions were also favorable for poor stalk quality in Northeastern Ohio, but stalk lodging was limited. Reduced stands due to poor emergence at these locations may have limited the potential for lodging.
Results of the 2001 testing program are presented in Tables 1 to 12. In the tables for the regional trials, yields and other agronomic performance characteristics have been averaged across the individual tests and shown under the SUMMARY heading. Hybrids are listed in increasing order of summary grain moisture content at harvest in the regional trials.
The unfavorable early season growing conditions contributed to uneven emergence and poor stands. Results of the Upper Sandusky test in Northwestern Ohio and the Canfield test in Northeastern Ohio were not presented because of the considerable variability in emergence and plant stand from plot to plot.
Confidence in test results increases with the number of years and the number of locations in which the hybrid was tested. 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.
Results of the 2001 corn performance tests programs may be found online at: http://www.ag.ohio-state.edu/~perf/.
We thank our farmer cooperators for their contributions to the 2001 corn hybrid testing program. We are grateful for the assistance provided by Clarence Renk, OARDC Western Branch; Lynn Ault, OARDC Wooster; Matt Davis, OARDC Northwest Branch; Jim Rich, FFA/Riverview High School; Andy Kleinschmidt, OSU-Van Wert Co. Extension; and Steve Prochaska, OSU- Crawford Co. Extension.
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Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
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