DuPont Pioneer research has consistently shown the value of timely soybean planting. Recent research efforts have also looked at the effects of planting varieties of different maturities at normal and earlier timings.
DuPont Pioneer scientists conducted a 2-year study evaluating planting dates to see if there is an advantage to earlier planting (late April and early May) at 9 Midwestern research locations. Results from this study indicate that yields were generally higher with a late April to early May planting date compared to later planting dates (Figure 1). These yield increases can be attributed to timing of soybean development stages and day length. Soybeans obtain higher yields when their critical developmental stages occur during longer summer days.
A subsequent research study evaluated the interaction of planting date and variety maturity on soybean yield. This study was conducted at 58 locations in Illinois and Indiana in 2011 and 2012.
In 37 locations, varieties differed by an average of 1 full maturity group. Results showed a significant interaction between planting timing and soybean variety maturity. Full-season adapted varieties had a greater average yield when planted early; whereas early maturing varieties yielded similarly across planting timings (Figure 2).
At the other 21 testing locations, varieties differed by half a maturity rating, on average. Varieties showed no significant interaction between planting timing and maturity (Figure 3).
Hybrid and variety responses are variable and subject to any number of environmental, disease and pest pressures. Individual results may vary. The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and management suggestions specific to your operation.