Should you revisit planting dates for corn?

Corn Corner: Take a long-lens view over time when considering first planting dates.
Oct 31, 2018
 
My early May-planted corn yielded well this year. I’m considering moving my target date from April 15 to May 5. Would that be a wise move? Why or why not?
 
The Indiana certified crop adviser panel answering this question includes Andy Like, Syngenta sales rep, Vincennes; Jeff Nagel, agronomist, Ceres Solutions, Lafayette; and Andy Shemwell, agronomist, Posey County Co-op, Poseyville.
 
Like: Over time, the best corn yields have been from planting in April. However, I have seen May corn outyield April corn with the right weather patterns. I would advise making a planting decision based on current weather, forecasted weather and field conditions. One pitfall would be not planting in April when the weather and field conditions are ideal, and then getting 6 inches of rain in May when you want to be planting corn. You could end up planting corn in June.
 
Nagel: Leaving your starting planting date at April 15 or so would be the wiser move. Most planting date studies over multiple years for Indiana and Illinois would suggest the optimum window for maximum yield is generally between mid-April and early May for corn and soybeans. Environmental conditions that favor good emergence, early establishment and growth during the growing season will ultimately drive yields.
 
Wet soil conditions are the main reason planting delays occur. While most farmers are equipped to plant their corn crop in seven to 10 days or less, waiting to start planting until May 5 could easily place you past the optimum planting window with one rainfall event. If ground conditions are generally favorable by mid-April and the forecast looks reasonable for the next several days, it’s time to plant.
 
Shemwell: If history and our past experiences tell us anything, it would probably be that earlier planting dates on corn, on average, will equate to higher yields in the fall. Soil types, soil conditions and weather conditions usually determine planting date. I have always said that the best planting date as determined by yield is determined by the weather conditions that we experience after planting, not before planting. In 2018, our earlier-planted corn was better than our late-planted corn. This was, in part, due to weather conditions at planting and weather conditions during pollination. 
 
As I said earlier, soil types and soil conditions will help determine planting dates. Our sandy soils should be planted earlier because they dry out earlier, and you can get corn planted early to try to beat the heat at pollination. Our heavier soils will be planted later because they tend not to dry out or warm up very early. We all tend to want to be on the early side when working ground, and that creates problems with soil compaction that we can see all year long. This will affect yield.
 
I would keep my target date in early to mid-April instead of moving it to May. Remember to plant when soil conditions are right to plant, not when you’re ready to plant.