Even early planting dates haven’t arrived for part for the Corn Belt yet. But in the central part, at least, farmers have grown accustomed to targeting April 15 as a date to start, or at least the last two weeks of April. Rainy conditions and excess flooding, leading to saturated soils in many areas, have many wondering when they’ll get that first chance to look for a planting window for ’08, let alone an ideal planting window.
Agronomists would caution that historically it’s still very early in the season. But data from many sources confirms reality- over the past several years the highest yields tend to come form late April to very early May planted corn, depending upon your exact location. Even Purdue University’s touted pocket field scouting guide begins to slow a very slight decrease in yield potential by May 5 vs. April 20. Potential doesn’t take serious drops in the table, based on averages over years, until past the middle of May.
Experiences at the Corn Illustrated plots near Edinburgh, Ind., in the central Corn Belt in ’07 indicated that in any year, whether it starts with an early spring or a late one, there are still good and not-so-good days to plant. The very first days may not be the ideal window, although the toughest days to plant may not always be the last ones in the season either. Adding to the frustration, there’s no way to know which days will be the best or worst in advance. Hindsight is always 20-20 when it comes to picking the best or worst days to plant corn. But even hindsight doesn’t become 20-20 in this case until the crop is in the bin in the fall.
The best day to plant in Edinburgh last year was around May 11, notes Dave Nanda, consultant for the Corn Illustrated project. That’s based upon a planting date demonstration study, not replicated data. And even though the Purdue table would favor May 7, the first date for which data was available in the study, May 11 yielded more last season.
The real losers last year at Edinburgh was anything planted on or after May 21. Those plantings looked good early, but ran out of gas when dry weather and extreme heat set in later in the season, The plots were on droughty soils, and these demonstration plots were not irrigated.
Nanda suggests looking for the best window you can find once conditions clear up. Ideally, find it by at least the first tow weeks in May, no matter where you live. After that time the capability fro capturing as much sunlight as possible during the season for maximum photosynthesis and yield begins to decrease in most years, he concludes.