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Posted 26 September 2014. PMN Crop News.

What is the Relationship Between Soybean Maturity Group and Yield?

Source: Michigan State University Press Release.

East Lansing, Michigan (September 17, 2014)--Producers are looking for ways to improve soybean yields and profitability and many are planting longer maturing soybean varieties as a way to reach these goals. The theory behind this strategy is that later maturing varieties will have a longer reproductive period and take full advantage of the growing season. However, planting later maturing varieties carries some risk. The most obvious risk is that the crop could be damaged by frost or freeze events, reducing yield and quality and increasing harvest delays. Additional risks include a greater potential for delayed wheat planting, early snow cover, harvest losses and soil compaction from harvesting when the soil is too wet.


Soybean agronomists recommend planting varieties representing a range of maturity groups that are adapted to a given area. Depending on the source, adapted varieties can range from one-half maturity group (e.g., 2.5 to 3.0) to one full maturity group (e.g., 2.0 to 3.0) for a given location. Planting varieties from a range of maturity groups reduces the risk of yield losses due to pests and environmental stresses occurring during the season. It also reduces harvest losses due to shattering by preventing all fields from being ready to harvest at the same time.

Information from the 2009-2013 Michigan Soybean Performance Reports was used as the basis for a preliminary investigation into the relationship between soybean maturity and yield in Michigan. The highest yielding varieties in each maturity group were selected from each of the trial locations from 2009-2013. The top four varieties were selected from the trials in the central zone and the top five varieties were selected from the southern zone trials. The average yield for each maturity group was calculated for each location and for each zone over the five-year period. This information and the average planting dates for each of the locations are presented in the following tables. The analysis assumes that producers will select the highest-yielding varieties for their farms.

This analysis does not show a strong relationship between soybean maturity group and soybean yield for the maturity groups listed. However, there was a trend for the 1.7 maturity group varieties to yield less than the other maturity groups in the central zone and for the 2.2 and 2.3 maturity group varieties to yield less than the other varieties in the southern zone. Based on this information, the range of maturity groups adapted for the central zone appears to be from 1.8 to 2.6 and between 2.4 to 3.2 for the southern zone. Based on this information, Michigan State University Extension continues to recommend planting a range of soybean maturity groups as long as the highest yielding varieties within the adapted maturity range for the area are selected.