Early Spring: Planting Date and Maturity Groups Factors

Doctors Adam Gaspar and Shawn Conley today released an issue of the Soy Report with major implications for Wisconsin regarding planting date and maturity groups.

Generally speaking, the more and longer the light, the better

Research shows planting in early May has led to increased yield. The engine for this boost? Increased light interception.

The reason boils down to this. Soybeans planted earlier get the benefit of more time in terms of days of reproductive growth—and especially reproductive growth during the longest days of the summer.

But when delays happen, Maturity Groups may help.

We all know things can happen on the farm. Logistical problems, bad weather or both might lead to delayed planting or the need to replant. And that’s where checking into Maturity Groups can be useful.

A recent 3-year study funded by DuPont Pioneer and the Wisconsin Soybean Marketing Board took a close look at five different planting dates across the state to gain the biggest yield.

Here’s what the data from 2014-2016 in trials at Arlington, Hancock and Spooner, Wi Showed. The five planting dates at each location were on or about (1) May 1th, (2) May 20th, (3) June 1st, (4) June 10th, and (5) June 20th.  ( Please note: Planting after June 20th is generally not recommended in WI)

Here is what the data show:

Table 1. Maturity Groups tested within each location and planting date.
Planting Date   Arlington Hancock Spooner
1 (May 1th) 2.5, 2.0, 1.5 2.5, 2.0, 1.5 1.5, 1.0, 0.5
2 (May 20th) 2.5, 2.0, 1.5 2.5, 2.0, 1.5 1.5, 1.0, 0.5
3 (June 1st) 2.0, 1.5, 1.0 2.0, 1.5, 1.0 1.0, 0.5, 0.0
4 (June 10th) 2.0, 1.5, 1.0 2.0, 1.5, 1.0 1.0, 0.5, 0.0
5 (June 20th) 1.5, 1.0, 0.5 1.5, 1.0, 0.5 0.5, 0.0, 00.5

The easy part you’ve heard many times before: the sooner you plant, the better, to maximize yield. If your soil is fit, the temperatures are above 50 degrees F and the forecast is looking good, go for it.

However, when situations or conditions may not be helping you along, earlier MG beans don’t show a quick and dramatic yield drop compared to later maturing varieties. Take a good gander at Figures 2 and 3.

The data show: planting early and using a longer MG soybean variety = no additional cost + opportunity for direct profit from increased yield

The Big Takeaway: Turn Synergies Into Opportunity

Let’s repeat the caption to the figures above because it bears repeating: “Clear yield synergies are demonstrated in Figure 2 and 3 from planting early and using a longer MG soybean variety.  Both management practices add no additional cost, meaning any yield increase is direct profit.”

Bottom line to you, as shown by the research of Drs. Gaspar and Conley,  is “planting a portion of your acres to slightly longer MG than normal within May can result in greater yields with no additional dollars spent.”

To conclude, early planting is best and can be ‘further maximized’ by planting longer maturity group beans. That said, while choosing a longer maturity group isn’t a sure thing for increasing yield, it puts more wind in your sails at no additional cost.

Or, as the good doctors say: “growers should give consideration to MG when selecting varieties, but past local and regional performance, disease package, SCN-resistance, etc. should also strongly be considered.”