Maturity Bell Curve

As harvest continues many producers have been or soon will be looking at what hybrids they will be planting next year. Yield is always paramount in those decisions; however agronomic placement is a close second as well. One factor not always apparent in some on of these decisions is maturity considerations or as some have put it the “Maturity Planting Bell Curve.” 

Maturity Planting Bell Curve is where you plant 10-25% of your crop to an early maturing hybrid or variety 50-80% to your standard maturity range and 10-25% to a later maturity. 

Planting multiple hybrids with different relative maturities helps reduce the risk of all crops pollinating during a hot and dry spell. By spreading out your relative maturity you, in theory, also spread out your harvest and drying facility load or bottleneck.

Agronomists and seed sellers over the years have typically recommended that producers plant hybrids that reach maturity 7 to 12 days before the average first freeze date. This allows time for products to reach R6 or Physiological Maturity / Black Layer naturally. (This in turn generally produces the best yield, test weight and also allows for better dry down.) The rule of thumb I use is that for every one day increase in relative maturity, you need to increase the Growing Degree Day or Unit (GDU) by 20-25 GDU to reach maturity. Conversely, in my experience, grain moisture will increase at harvest .2 to .5 percent for every one day increase in relative maturity.

I often recommend that growers begin planting with an early or standard maturity hybrid in their first field, followed by later-maturing hybrids, and then complete the rest with a mix of their remaining selections. The reason being is not to have all of hybrids pollinating at the same time. If you plant all of your later day relative maturity first, followed by your normal relative maturity and then your early day maturity, odds are they will all pollinate at the same time, which increases your risk of inclement weather at pollination. The other aspect of this is that by planting an early relative maturity first on a field or two, you are also allowing for greater harvest flexibility and or capturing a grain marketing opportunity.

If you have question regarding what hybrids or maturity range is best for your operation, please contact your local Dairyland Seed Dealer, District Sales Manager or Agronomist to help with these needs.