Source: Greg Roth, Grain Crop Management, Penn State University

Everyone is anxious about the wet spring and the potential of yield reductions from delayed planting. But it's still not time to hit the panic button on this issue. First, it is still early for most parts of the state and these days we have lots of potential to plant acres rather quickly, with our larger and newer planters. Secondly, corn yields really don't start to decline steadily in plot yields until after May 1 in many areas and even later in May in some of our shorter season areas. A recent Illinois planting date study demonstrated this. Third, planting date is only one of many variables that influence yield in a given season, and some of our best yields have occurred in years when planting dates have been delayed. In this USDA NASS plot of planting date progress in 2010 and 2009, notice that corn planting was only 50 percent complete in 2009 by mid May compared to about 75 percent complete in 2010. Statewide, yields averaged 143 bu/acre in 2009 or about 15 bu/acre higher than in 2010, despite the delayed planting. In recent Kentucky analysis, my colleague Chad Lee compared corn yields and planting dates from a large number of fields over a four year period. He found the highest yields occurred in central Kentucky between April 29 and May 10, a bit later than his recommended optimum planting dates. To me, this suggests that in years with wet springs, the response to early planting may not be as great. The bottom line is that we still have potential for good corn yields, even if corn planting gets delayed a bit.

Wet Conditions and Delayed Corn Planting