James E. Beuerlein, Professor, Dept. of Horticulture &
Crop Science
Steve St. Martin, Professor, Dept. of Horticulture & Crop
Science
Anne Dorrence, Assistant 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.
2002 Ohio Soybean Performance Trial Entries in Order of Relative Maturity
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 2002 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 maturity grouping of each variety type at 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. 2002 rainfall is shown in Table 2. Wet conditions in early-mid May followed by droughty conditions in June, July and August severely impacted yields at the Mercer and Delaware County sites.
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Table 1. 2002 Cultural Practices by Test Site |
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| N1 | N2 | C1 | C2 | S1 | S2 | |
| Henry Co. | Huron Co. | Mercer Co. | Delaware Co. | Preble Co. | Clinton Co. | |
| Fall Tillage | None | Plow | Chisel | None | None | Chisel |
| Spring Tillage | None | Field Cultivator | Disk | None | None | Field Cultivator |
| Soil Type | Hoytville | Kibbie | Mercer | Blount | Crosby | Westland |
| Soil pH | 6.8 | 5.6 | 6.5 | 6.4 | 6.6 | 5.6 |
| Soil Test P(ppm) | 54 | 57 | 23 | 49 | 78 | 44 |
| Soil Test K(ppm) | 185 | 159 | 199 | 306 | 298 | 153 |
| Fertilizer | 0-0-0 | 0-0-0 | 0-0-0 | 0-0-0 | 0-0-0 | 0-0-0 |
| Previous Crop | Corn | Soybean | Corn | Corn | Corn | Corn |
| Plant Date | 5/23 | 5/22 | 5/24 | 5/27 | 6/2 | 6/3 |
| Harvest Date | 10/10 | 10/11 | 10/9 | 10/3 | 10/8 | 10/7 |
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Normal Variety Weed Control |
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| Preemerge |
Canopy XL/Dual II/Roundup/UltraMax Roundup used at all test sites. |
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|
Postemerge |
Basagran/Flexstar/Select used at all test sites. |
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|
RR Variety Weed Control |
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| Pre/Postemerge |
Roundup UltraMax used at all test sites. |
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Table 2.
2002 Rainfall Data |
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| N1 | N2 | C1 | C2 | S1 | S2 | |
| Henry Co. | Huron Co. | Mercer Co. | Delaware Co. | Preble Co. | Clinton Co. | |
| May | 7.9(3.3) | 4.0(3.6) | 5.5(4.1) | 4.7(3.8) | 7.2(3.8) | 8.1(4.7) |
| June | 3.7(3.5) | 2.5(3.9) | 1.5(3.8) | 2.6(3.8) | 5.3(3.9) | 4.6(3.6) |
| July | 5.3(4.0) | 1.7(4.2) | 1.8(4.4) | 0.9(3.8) | 3.3(3.4) | 5.3(3.9) |
| August | 4.9(3.1) | 3.1(3.5) | 3.0(3.6) | 2.0(3.1) | 1.3(3.1) | 3.6(3.5) |
| September | 6.4(2.8) | 3.9(3.2) | 2.6(3.3) | 3.0(2.9) | 5.1(2.7) | 7.2(3.0) |
| TOTAL | 28.2(16.7) | 15.2(18.4) | 14.4(19.2) | 13.2(17.4) | 22.2(16.9) | 28.8(18.7) |
MEASUREMENTS AND RECORDS
Relative maturity. Relative maturity is a rating designed to account for all of the factors that affect maturity date and number of days from planting to maturity. These factors include variety, planting date, weather, latitude and disease. The method used to determine maturity was the 95% brown pods reading. 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.
Plant height was taken just prior to harvest from the S2 site where plants were moderately tall with some lodging. The average height (inches) of several plants was recorded.
Lodging score. Data collected at S2. 1 = nearly all plants erect; 2 = most plants leaning slightly; 3 - most plants leaning moderately (45); 4 = most plants horizontal well above soil surface; 5 = 80 percent or more of plants down on soil surface.
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 Tekator 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. An "S" indicates the variety is segregating for resistance and not all of the plants carried an Rps gene. Two genes indicated by "2Gen" that the variety has an Rps gene combination of either 1c+3a or 1k+3a. "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.
Sclerotinia Rating. There are no known sources of resistance to Sclerotinia that will totally eliminate disease development. The resistance to Sclerotinia is a type of partial resistance where less disease - fewer plants develop Sclerotinia than more susceptible varieties. In this year=s test, all of the varieties were susceptible. Varieties identified with "n" have normal (high) susceptibility. Some varieties have a moderate level of resistance to Sclerotinia and are identified with an "MR." If inoculum levels are high and the environment is very favorable, all varieties will develop Sclerotinia stem rot. The moderately resistant varieties will develop much less disease than varieties without the MR designation.
Yield. Each soybean variety was harvested at a moisture content between 10 and 17 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.
11/2002
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State University Extension are available to clientele on a nondiscriminatory
basis without regard to race, color, creed, religion, sexual orientation,
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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.