All yield and seed data were reported on a 13% moisture basis. Seed protein content for the three standard cultivars in the MG II test ranged from 33.4% to 35.1% averaged over all locations. The seed protein content of the high-protein strains ranged from 35.9% to 43.6%. Yield of the high-protein strains, expressed as a percent of the 3-check average, ranged from 66.3 % to 104.4% of the checks. The high-protein strains produced soybean meal with 49.3% to 55.5% protein. Fourteen strains produced protein meal with an average of over 50% protein and averaged greater than 90% of the standard high-yield cultivars.
For the MG III test, seed protein content for the standard cultivars ranged from 34.2% to 35.7%, while the protein content in the high-protein strains ranged from 36.7% to 41.7% in whole seeds. Yield of the high-protein strains ranged from 78.3% to 100.1% of the average of the three standard cultivars. The high-protein strains produced soybean meal with 49.6% to 54.7% protein. Six strains produced a protein meal with an average of more than 50% protein and yielded greater than 90% of the standard cultivars.
For the MG IV test, seed protein content for the standard cultivars ranged from 35.4% to 35.9%, while the seed protein content in the high-protein strains ranged from 36.6% to 43.3%. Yield of the high-protein strains ranged from 77.0% to 93.6% of the average of the three standard cultivars. The high-protein strains produced soybean meal with 50.1% to 55.9% protein. Three strains produced a protein meal with an average of more than 50% protein and yielded greater than 90% of the standard cultivars.
For the MG V test, seed protein content for the standard cultivars ranged from 33.8% to 35.5%, while the seed protein content in the high-protein strain ranged from 35.5% to 39.7%. Yield of the high-protein strains ranged from 83.6% to 107.2% of the average of the three standard cultivars. The high-protein strains produced a soybean meal with 48.3% to 52.2% protein. Five strains produced a soybean meal with at least 50% protein and yielded at least 90% of the standard checks.
In summary, there are high-protein soybean strains that will produce soybean meal with 50% protein or greater and have competitive yield and good agronomic traits. This regional test is a valuable program for obtaining information on regional performance of new high-protein soybean lines, and for facilitating the exchange of information and germ plasm among breeding programs involved with compositional quality. Results from this research will be transferred directly to the soybean farmer in the form of new high-yield varieties with higher protein content.
Tests were planted in four-row plots with two or three replications per location. The center two rows were used for all data collection.
Yield is measured after the seeds have been dried to a uniform moisture content and is recorded in bushels (60 lbs) per acre, adjusted to 13% moisture.
Maturity is the date when 95% of the pods have ripened. Delayed leaf drop and green stems are not considered in assigning maturity. Maturity is expressed as days earlier (-) or days later (+) than the average of the reference variety. To aid in the maturity classification, one variety from an earlier group and one later (L) check variety from the same group are given in the maturity column for each test in maturity groups 2 and 3. In maturity groups 4 and 5 only one later check is given in addition to the reference variety.
Lodging is rated at maturity according to the following scores:
1 Most plants erect.
2 All plants leaning slightly or a few plants down.
3 All plants leaning moderately, or 25 to 50% down.
4 All plants leaning considerably, or 50 to 80% down.
5 Most plants down.
Height is average length from the ground to the tip of the main stem at maturity, measured in inches.
Seed Size is measured in weight in grams per 100 seeds.
Seed Composition was measured in duplicate on a 500g sample by Dr. Charles Hurburgh, Grain Quality Lab, Iowa State University, Ames, IA. Locations with LSD’s used protein samples from each plot and locations without LSD’s sent in a composite sample from all reps. The protein, oil, moisture, and fiber content of the sample was determined by near-infrared spectroscopy on an Infratec 1229 whole-seed infrared analyzer machine. All seed composition measurements are adjusted to a 13% moisture basis.
Meal Protein and EPV (estimated processed value) were determined using the SPROC program (Brumm and Hurburgh, 1991). The specified product was a 48% protein meal with 3.5% maximum fiber content. For calculation of EPV, the value of mill feed was $0.01/lb, oil $0.155/lb and $148/ton for 48% soybean meal.
Estimated Processed Value per Acre (EPVA) was determined by EPV x Yield.
Yield vs
Checks is the yield of that strain vs. the average yield of the checks
in that test
stated as a percentage.
Yield of the strains was also expressed as a percentage of the 2 or 3-check average in the regional summary for each test.