According to a U.S. Department of Agriculture report, 11% of Ohio's had been planted by May 23. While forecasters predict improving weather, corn planting has already been delayed enough that plant maturity could become an issue.
"One of the biggest agronomic concerns with severely delayed planting is the risk of the crop not reaching physiological maturity before a killing fall freeze and the yield losses that could result," says Bob Nielson, Purdue agronomist. "An economic concern with delayed planting is the risk of high grain moistures at harvest and the resulting costs incurred by drying the grain or price discounts by buyers."
At http://www.agry.purdue.edu/ext/corn/news/articles.11/SafeHybridMaturities-0517.html, Nielsen offers tables that list relative hybrid maturities for corn planted through June 10, based on heat unit requirements and anticipated "normal" accumulation of heat units between planting and an average date of a killing fall freeze.
But while faster-maturing hybrids should reach maturity by their projected dates, severely delayed plantings still are likely to mature later in the fall when further in-field grain drying is at a slower pace.
"Grain moisture at harvest for delayed plantings may be unacceptably high in terms of both the ease of harvest and the cost of artificially drying the grain," Nielsen says.
He also noted that farmers can somewhat mitigate that frustration by planting even earlier-maturing hybrids, but even then there may not be a great difference in grain moisture.
"Typically, a one-day difference in relative maturity rating equals 0.5% difference in grain moisture content at harvest," Nielsen says. "That means there will only be about two points difference between a 106-day hybrid and a 110-day hybrid, for example, at harvest."
Another factor corn growers should consider is the economic gain from corn to soybeans as planting is further delayed.
"The economic estimates are difficult because of the many varied agronomic and economic assumptions that influence the calculation, such as the expected yield from delayed planting," Nielsen says.