Soybean Experimental Procedures

Test Descriptions:

Glyphosate Resistant Soybean Test: This test includes glyphosate resistant varieties and receives a postemergence application of glyphosate.

Non-Glyphosate Resistant/ Special Traits Soybean Test: This test is a combination of the Non-Glyphosate Resistant Soybean Test and the Special Traits Soybean Test. Examples of soybean lines with special traits include tofu, natto, food grade, isoflavone, high oil, fatty acid profile, and high protein. Three high yield check varieties were included in these tests for comparison.

Entries:
All producers of soybean varieties were eligible to enter the 2008 soybean evaluation tests. Participation was voluntary and the test coordinators exercised no control over which or how many varieties were entered. To help finance the evaluation program, the participants paid $100 per location for each variety entered.

Plot Management:
All test plots were planted and harvested with commercial equipment modified for small plot work. Row spacing for soybean tests in the North, Central and Southwest Regions was 15 inches. Row spacing for soybean tests in the Southeast Region was 30 inches. Seeding rate for the 15-inch and 30-inch row spacing was 174,200 seeds/acre. Fertilizer was applied at each location at the discretion of the farmer or the station manager. Weed control was achieved with Roundup herbicide for the Glyphosate Resistant Tests and various other herbicides for the Non-Glyphosate Resistant/Special Traits Tests and additional hand weeding was done as required. Management details varied from location to location and are specified in the regional crop management summaries.

Data Recorded:
Maturity group classification is provided by the entry sponsor. Maturity data are recorded when approximately 75 percent of the pods have turned color. Lodging and height are determined immediately before harvest. A scale of 1 to 5 is used to score lodging. Interpretation of the scale is as follows:

1 = all plants erect
3 = all plants leaning moderately or 20 to 50% down
5 = all plants down

Data on maturity, plant height, lodging and yield are given for each entry and location. Yield is measured in bushels (60 pounds) per acre at a moisture content of 13.0 percent. An electronic moisture tester is used for all moisture readings.

All soybean locations were tested for the presence of SCN eggs in the soil before planting. Every effort was made to locate the test sites in fields of low to moderate levels of SCN. These numbers are given in the heading information of each table.

Field Plot Design:
Statistical designs used to analyze the field data included randomized lattice with three replications and randomized complete block with four replications, depending on the size of the test. Individual plots were four rows wide for the 15-inch row spacing and two rows wide for the 30-inch row spacing with a row length of 25 feet for both. All four rows of each plot were harvested for the 15 inch row spacing test and both rows of each plot were harvested for the 30-inch row spacing to determine yield.