SELECTION -- Soybean variety selection
should be based on maturity, yield, seed quality, lodging, iron-deficiency chlorosis tolerance, soybean cyst nematode and disease reaction. Later-maturing varieties tend to yield more than early maturing varieties
when evaluated at the
same location. After determining a suitable maturity for the farm, comparing yields of varieties that are of similar maturity is important. In the tables the varieties are sorted by maturity provided by the companies and by company name. Although late maturity increases yield potential, later-maturing cultivars are more risky to grow than earlier-maturing varieties because an early fall frost, like in 2011, may kill a late-maturingvariety before the beans have completely filled in the pods, which will reduce yield greatly. Varieties of maturity groups 00 (double zero), 0 (zero) and 1 are suitable for eastern North Dakota and northwestern Minnesota. Maturity group 00 is very early and primarily grown in the northern Red River Valley and the northcentral area of North Dakota.
The best way to select a high-yielding variety is to use data averaged across several locations and years. Because weather
conditions are unknown in advance, averaging across several years’ data will identify a variety that likely will yield well across different weather conditions. Selecting a variety that has performed well in dry and
moist conditions is the best way to pinpoint a variety that does relatively well, regardless of weather fluctuations.
IRON-DEFICIENCY CHOLOROSIS - Iron-deficiency chlorosis (IDC) is a major problem in the eastern part of North Dakota and northwest Minnesota. Iron chlorosis symptoms might be present
during the two- to seven-trifoliolate-leaf stages. Plants tend to recover and startto turn green again
during the flowering and pod-filling stages. However, IDC during the early vegetative stages can reduce yield severely. Some varieties are more tolerant to IDC than others. For high pH soils with known IDC problems, select an iron chlorosistolerant variety of suitable maturity that is high yielding. The 2001-10 variety IDC scores are posted at www.yellowsoybeans. com.
Tn the table, IDC data is presented from 2010 as the trial in 2011 was flooded and no reliable data could be generated.
The IDC is expressed as a score between 1 and 5, with 1 being a variety without IDC symptoms and 5 a plant which is showing severe IDC symptoms. There is also a letter grade, from A to D-, representing how a variety rated compared with the other varieties. The range in the scores of commercial varieties is divided into 11 categories (A, A-, B+, B, B-, C+, C, C-, D+, D, D-), and the varieties were placed i Harvesting soybean variety trials with a research plot combine. nto these 11 categories. In other words, the most resistant commercial variety defined the top end of the “A” range, and the most susceptible commercial variety defined the bottom of the “D-” range.
YIELD TABLE - In 2011 about 370 Roundup Ready
company named varieties were entered in North Dakota and Minnesota University variety trials. Due to limited space, only varieties with multiple observations could be included in this publication. In Table A, the
full company names are given and the abbreviated form used in the table as well as the websites for additional information.
Producers are encouraged to look at the tables for a quick overview of the yield across different sites. The yield is
expressed as a percent of the mean of the test location. If the number is 100, it indicates that the yield was equal to the mean of all varieties tested at that location. If the number is higher than 100, it
indicates that the yield was higher than the trial mean. The mean of each location is found on the top of each location column. For more detailed information about each North Dakota location see the 2011 ND
Soybean performance booklet. http://www.ag.ndsu.edu/pubs/ plantsci/rowcrops/a843.pdf. For information about the varieties tested in Minnesota see http://www.soybeans.umn. edu/crop/variety/State_Trials/index.htm.
Northwest Minnesota trial information can also be obtained from the Regional Extension Center in Crookston.
The tables are based on the information provided by numerous researchers including, Blaine Schatz, Carrington; Walter
Albus, Oakes; Mark Halverson, Minot; Ted Helms, NDSU main campus; Jay Goos, IDC; Bryan Hanson, Langdon; Jim Orf, Seth Naeve, P.J. Schaus and Art Killam, official U of M trials; Russ Severson, Howard Person, Carlyle
Holen and others, NW Minnesota county plots; and Ken Pazdernik, Norman County.