Should Wisconsin Farmers Use Soybean Maturity Group as Tool for Variety Selection?

Madison, WI, January 13, 2015 – For 2015, Wisconsin farmers may be asking, ‘how much weight should we give to maturity group when making seed decisions’?  “Not much,” according to Shawn Conley, University of Wisconsin (UW) Extension soybean specialist.

Conley says in recent years, there has been a subtle shift across much of the northern soybean growing region to planting later maturity group soybeans.

“This shift, either conscious or unconscious, may be attributed to earlier planting dates, relatively favorable fall harvest windows, and the drive for maximum yield as influenced by high commodity prices,” Conley says. “As with all trends sooner or later, we have a correction year. 2014 was that year for many farmers.  So now, as farmers, consultants and the battered and bruised seed suppliers sort through the plethora of product offerings for 2015 they again will be considering maturity group decisions.”

In 2011, the Wisconsin Soybean Research Program published an article in the journal Crop Management entitled: “Optimal Soybean Maturity Groups for Seed Yield and Quality in Wisconsin” (Furseth et al, 2011). In this data set, researchers looked at 893 varieties across six growing seasons (2004-2009) and three production regions in Wisconsin.

“Within each region we identified the optimal maturity group range for maximum yield,” Conley says. “Those were 2.6-2.9, 2.1-2.4, and 2.0-2.2 for our southern, central and north central regions respectively. Figures suggest that regardless of growing region in Wisconsin, growers can select a variety that is almost one full maturity group earlier than the optimal maturity group range for maximum yield and still be within 10 percent of maximum yield.”

“In our recently released 2014 WI Soybean Variety Test Results book, the range that included a starred variety (starred varieties do not differ from the highest yield variety in that test) was 1.9-2.8, 1.1-2.4,and 0.9-2.0 in our southern, central and north central regions respectively,” says Conley. “This amplifies my assertion that the “relative” maturity group rating is trumped by individual cultivar genetic yield potential.”

“As seed decisions are made for 2015, it is fine to keep the relative maturity rating on your check list, just don’t have it near the top,” says Conley.

To read Conley’s complete assessment on this topic, visit http://thesoyreport.blogspot.com/.