The June plots in general in a research study at the Throckmorton Research Center likely yielded more corn at dry yield than any other plots or bulk corn on the farm. That's a true statement. However, it's true only for the topsy-turvy 2012.
Bob Nielsen, a Purdue University Extension corn specialist, has cautioned against making too much out of 2012. Even though these were replicated plots, he still cautions that the results apply to this one situation in this one year. There are reams of data indicating that early planting pays over a period of years in terms of higher yields.
The June 7 plot yielded better than the same trial planted May 20. While final yields have yet to be calculated, the likely advantage was 10 bushels per acre or more. However, the higher yield came with a cost.
According to the readout on the yield monitor, the corn for the same hybrid in the latest-planted plot was about 3 full percentage points wetter than corresponding plots in the May 20 planting. That was true even though the plots were harvested on the day before Thanksgiving. Obviously, little or no dry-down was still occurring in the field because of weather conditions in late November.
The other difference was in lodging. There was noticeably more lodging and down corn in the June 7 planted corn. In some cases plants were flattened at ground level. In other cases lodging was due to a break in stalk integrity higher up in the plant. Many stalks didn't respond when pushed over, indicating the presence of stalk rot. The later-planted corn also appeared to consist of more spindly stalks than the earlier-planted plot. However, this observation was purely objective. No measurements were taken for comparative purposes.
When you sit down to determine which planting date made the most profit, you would have to balance the higher yield by the wetter moisture, which either meant a drying charge, shrinkage and or a dock per moisture point, depending on if you dried it yourself or where you sold the corn.