Ohio Soybean Performance Trials 2005

James E. Beuerlein, Professor, Dept. of Horticulture & Crop Science
Steve St. Martin, Professor, Dept. of Horticulture & Crop Science
Anne Dorrence, Associate Professor, Dept. of Plant Pathology
Chris D. Kroon Van Diest, Research Associate, Dept. of Horticulture & Crop Science

Ohio State University Extension /OARDC
The Ohio State University, College of Food, Agriculture and Environmental Science

The purpose of the Ohio Soybean Performance Trials is to evaluate soybean varieties, brands and blends for yield, and other characteristics. This evaluation gives soybean producers comparative information for selecting the best varieties for their unique production systems.

METHOD OF CONDUCTING TRIALS

Entries in trials. Entries in the Ohio Soybean Performance Trials are accepted if the seed will be available to Ohio farmers for the planting season following the trials. All 2005 entries were submitted voluntarily by seed companies and the Ohio Seed Improvement Association. Entry fee charges were made per entry and location.

Normal and Roundup Ready (RR) Test. The same production, testing and evaluation techniques, except for weed control, were used for Normal tests and Roundup Ready tests. The performance of Normal entries and Roundup Ready entries is not comparable statistically because they were not tested together and because different weed control programs were used for the two tests.

FIELD PLOT DESIGN

The entries for each test site were planted in a randomized complete-block design. Each entry was replicated four times and planted in plots 45 ft. long and 5 ft. wide containing four rows seeded at 170,000 seeds per acre.

PRODUCTION PRACTICES AND RAINFALL

The production practices used at each location are shown in Table 1 and 2005 rainfall is shown in Table 2.

MEASUREMENTS AND RECORDS

Relative maturity. Relative maturity is a rating designed to account for all of the factors that affect maturity date and includes variety, planting date, weather, latitude and disease. Maturity is defined as the “95% brown pods” stage. A variety with a Relative Maturity rating of 3.5 will reach the 95% brown pod stage 5 days later than a variety with a rating of 3.0. September and October weather increased the length of time over which varieties matured and many varieties reached maturity up to 16 days later than normal although their “relative maturity” increased by only two to four days. All the varieties in a table were tested as a group, and their performance analyzed and reported for that group regardless of their 2005 relative maturity rating.

Plant height was taken just prior to harvest from the N1 and S2 sites where plants were moderately tall with little lodging.

Lodging score. There was no lodging in 2005.

Seed size is reported as 1000s of seeds per pound.

Protein and oil % analysis was determined by near infrared transmittance technology. The test was performed by the OSU Grain Quality Lab using a Tecator Infratec whole grain analyzer calibrated with the Composition Systems Calibration developed at Iowa State University and is reported at 13% moisture.

Phytophthora Resistance Genes. Phytophthora resistance genes were determined using a hypocotyl inoculation test. In this test, several races of Phytophthora are used to determine the presence or absence of a particular Rps gene. The Rps genes (Rps1a, Rps1c, etc.) detected in a variety are listed in Tables 3 8. “SEG” indicates the variety is segregating for resistance and not all of the plants carried an Rps gene. “2gen” indicates that the variety has an Rps gene combination of either 1c+3a or 1k + 3a. “2gen(8)” indicates one of the two genes is the new Rps 8 phytophthora gene. “None” indicates no resistance genes were detected.

Phytophthora Partial Resistance. All varieties were evaluated for partial resistance. Partial resistance is a multi genic characteristic that provides some level of protection against all known races of Phytophthora. Ratings of 3.0 to 3.9 are considered high levels of partial resistance and will provide good levels of control. Ratings of 4.0 to 5.9 are considered moderate and will allow some yield loss when environmental conditions favor Phytophthora. Ratings over 6.0 indicate very little partial resistance or protection against Phytophthora. For Ohio Producers with fields with a history of Phytophthora root and stem, varieties should have a combination of Rps genes plus partial resistance to Phytophthora for the best protection. Data for some varieties was not available at press time but is available on the Internet at: www.agcrops.osu.edu

Cruiser Use. For Ohio Producers with fields with a history of Phytophthora root and stem, varieties should have a combination of Rps genes plus partial resistance to Phytophthora for the best protection.

Yield. Each soybean variety was harvested at a moisture content between 9 and 15 percent and yields computed to bushels per acre at 13 percent moisture.

LSD. A Least Significant Difference (LSD) for yield was computed for each maturity group. LSD's are reported in bushels per acre at 13 percent moisture. Yields of two varieties within a maturity group are significantly different 70% of the time if their yields differ by more than the LSD value shown for that maturity group.

DATA USE

Inclusion of entries in the Ohio Soybean Performance Trials does not constitute an endorsement of a particular entry by the Ohio State University, Ohio Agricultural Research and Development Center, or the Ohio State University Extension.

11/2005
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Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.