2008 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 2008 test are listed in footnotes below the tables. At the time this publication went to press, soil test analyses were not yet completed. When the results are available, they will be posted online.

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 STARCH). 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. At the time this publication went to press, grain protein, oil, and starch analyses were not completed. When the results are available, they will be posted online at http://www.oardc.ohio-state.edu/corntrials/ and http://agcrops.osu.edu/~perf/ .

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 $3.75 per bushel and $0.05 drying charge for each percentage of moisture above 15.5%.

2008 GROWING CONDITIONS

Environmental conditions varied greatly across Ohio during the 2008 growing season, especially with regard to the amount and distribution of precipitation. At most test sites, rainfall from planting through the mid to late vegetative stages of corn development was above normal. It was the wettest June on record in many areas of Ohio. Excessively wet soils in May and June limited early season root development and resulted in shallow root systems. Dry weather conditions persisted from the late vegetative stages through maturity at most sites. Water deficits were especially severe in the Northwestern region especially at the Hoytville test site. At other test sites, water stress was limited by timely rains and adequate soil moisture. On September 14, record high winds associated with hurricane Ike caused severe root and stalk lodging at the test sites in Southwestern/West Central region and at the Hoytville test site in Northwestern Ohio. Slower than normal crop development in parts of northern Ohio contributed to higher than normal harvest grain moisture at the Beloit and Bucyrus test sites. Disease and insect pests were not a significant factor at most test sites. However, the western corn rootworm variant was observed for the first time in the hybrid performance trial at S. Charleston (which followed soybean) and caused considerable root lodging among hybrids without the Bt rootworm resistance trait.

RESULTS

Results of the 2008 testing program are presented in Tables 1 to 10. The seed source and table location for hybrids tested in 2008 are shown in Table 11. The transgenic herbicide and insect resistant events and insecticide and fungicide seed treatments associated with each hybrid entry (information provided by seed companies) are indicated in Table 11. Hybrids that do not contain transgenic events are specified as “NON-GMO”. 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.

Performance data for the Van Wert test site in the Northwestern region are not presented. At this site, drought stress damage combined with variable field conditions resulted in inconsistent yields. Although growing conditions were drier than normal during the grain fill period (approx. mid July through early September) and stalk and root lodging was greater than normal, excellent yields were recorded at most test sites. Yields, averaged across hybrid entries, exceeded 200 bu/A at S. Charleston, Washington C.H., Greenville, Bucyrus and Coshocton.

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 2008 corn hybrid testing program. We are grateful for the assistance provided by Clarence Renk and Joe Davlin, OARDC Western Branch, Lynn Ault, OARDC Wooster, Matt Davis, OARDC Northwest Branch, Jim Rich, FFA/Riverview High School, Gary Prill and Andy Kleinschmidt, OSU-Van Wert Co. Extension, and Steve Prochaska, OSU- Crawford Co. Extension. We thank Tim Bowman in Communications and Technology for his assistance in preparing the test results for publication.

11/2008
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