The relative maturity (RM) of a variety is supposed to give farmers a relative indication of how long that variety takes to get to harvest maturity. But the problem with relative maturity is that there is no standardized system by which seed companies assign relative maturities to their varieties.
Because seed companies may have different methods for assigning maturity numbers to varieties, varieties from different seed companies may not necessarily have the same season length even if they’re labeled with the same relative maturity. Also, many farmers worry that companies might not be fully transparent regarding maturity numbers, changing numbers slightly in order to fill gaps in their lineup or end up with a more marketable variety.
The lack of transparency and consistency of current relative maturity values makes it difficult for farmers when they’re making seed decisions. At FBN, we've seen different brands sell the same variety in the same region with as much as a 5 "day" difference in corn, and half a maturity group in soybeans. On top of that, the units of relative maturity are confusing and widely misinterpreted1, since they are not actually calendar days between planting and maturity.
Furthermore, seed companies typically assign a single national relative maturity rating, even though the actual season length required for maturity can vary by region. For example: 101 day corn grown in central Nebraska does not have the same season length as 101 day corn grown in central South Dakota.
Farmers may end up not considering varieties that are actually well suited for their region if they only focus on relative maturity numbers.
At FBN, a big part of our mission is testing conventional wisdom by putting it to the test through an unbiased analysis of anonymous, aggregated data from real farm operations. That’s why we're excited to supplement relative maturity with a very clear, quantitative, and simple metric of season length—simply, the calendar days between planting and the time when the crop reaches the typical harvest moisture for the region.
FBN now shows the estimated Season Length of each variety personalized for a farmer's region in FBN Seed Finder. This leverages real-world data contributed by FBN farmers to measure how long varieties typically take to become ready for harvest. This number is shown next to relative maturity in Seed Finder, and is measured in the average number of days it takes that variety to go from planting to harvest in the enterprise's region.
Season Length is currently available for corn and soybeans, and only for varieties and regions where there is sufficient data to run the analysis. Not all farmers will be able to access season length predictions for the same or all varieties. Since predictions depend on location, farmers need to have fields created in FBN to access predictions for their farm.
Sources
https://www.agry.purdue.edu/ext/corn/news/timeless/hybridmaturity.html
FBN Direct Services are offered by FBN Inputs, LLC and are available only in states where FBN Inputs, LLC is licensed. FBN Crop Marketing is offered by FBN CM LLC and is only available where FBN CM LLC is licensed.