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 that have unique
environments. The Coshocton location (east central Ohio) is in an area of high
gray leaf spot incidence. The Piketon location (southern Ohio) is representative
of river bottom fields in southern Ohio. Evaluation techniques for hybrids at
these sites 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 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/ 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 2002 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 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.
Environmental conditions varied greatly across Ohio during the 2002 growing season, especially with regard to the amount and distribution of precipitation. Cool, rainy weather delayed planting, and wet soil conditions during emergence and early vegetative growth resulted in restricted, shallow root systems. These factors combined with a drought that began in mid June severely reduced yields at Wooster, Upper Sandusky, Hoytville, Van Wert, and Greenville. Rainfall deficits were most pronounced at test sites in the Northwest and Northeast.
Results of the 2002 testing program are presented in Tables 1 to 11. The seed
source and table location for hybrids tested in 2002 are shown in Table 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.
Unfavorable early season growing conditions followed by drought sharply cut yield potential at five test sites. Results of the Upper Sandusky test in Northwestern Ohio and the Wooster test in Northeastern Ohio were not presented because of field variability and very low yield levels.
Take precautions when using hybrid performance data this year. Severe stress can undermine the value of test plot information. Drought and other yield limiting factors may accentuate the natural "variability" already existing in the field, and may "mask" the true treatment effects that are being compared. Stress conditions coupled with slight differences in soil organic matter, drainage, weed control, etc. across a field may magnify differences in crop performance.
Interpretation of test plot data becomes an important consideration when evaluating results of a hybrid performance trial severely affected by drought. Slight variation in growth and development among hybrids may translate into major yield differences. Did a hybrid yield well under drought stress because it genuinely possesses some drought resistance or because it "escaped" the drought by flowering before or after the worst of the stress? If it was the latter, then the hybrid's superior performance may be of limited value under different drought conditions in the future. When a drought occurs late in the season, then short season hybrids may have an advantage over full season hybrids; if the drought occurred earlier, but is broken by rains later in the season, then the full season hybrids may have the advantage.
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.
Results of the 2002 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 2002 corn hybrid testing program. We are grateful for the assistance provided by Clarence Renk, OARDC Western Branch, Lyn 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.
Go to Ohio Crop Performance
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868