With corn harvest lagging by 25% or more behind the norm, moisture spot checks indicating very wet grain and more unfavorable drying weather in the near-term forecast, some corn growers may already be considering leaving corn stand in the field until spring.

"Many factors influence the decision to harvest yet this fall or delay until spring," says Nick Schneider, a University of Wisconsin county ag extension agent. "Some factors can be assessed now, such as stalk strength, ear health, insect damage and shank attachment."

Schneider says a crop that has weak plant integrity now is at greatest risk of crop losses if harvest is delayed. Fields with good stalk strength and a soundly attached ear might be good candidate fields for delaying harvest.

"However, crop health only has one direction to go — down," Schneider says. "Beyond plant integrity, factors such as wildlife damage and weather will play a major role in ear retention the following spring."

If a corn grower is seriously considering leaving corn stand through winter, Schneider says the most important question that needs to be answered is whether the revenue lost by winter crop damage will be less than the cost of drying this fall.

"If the value of corn loss over the winter from ear drop, fungus or animal feeding is more than the drying bill would have been if harvested this fall, then it doesn’t make sense to leave corn stand until spring," he says.

As corn prices increase, the producer can tolerate paying a greater price for drying, Schneider says. Additionally, as the percentage of yield loss through winter increases, the producer also can justify paying a greater drying cost.

For example, Schneider says if this winter has heavy snowfall, similar to 2000, with a 38% yield loss by April harvest, the producer would be able to pay just over $1.31 per bushel for drying corn worth $3.75 per bushel (2009 price) to generate the same amount of revenue.

But if conditions are more like the winter of 2001 with only a 10% yield loss and a price of $3.75 per bushel, then the grower keeps more revenue by letting the corn stand in the field if drying costs are more than 38 cents per bushel.

If in an average year, 25% of corn yield is lost over the winter, at $3.75 per bushel the grower can pay up to 94 cents per bushel for drying and break even with field loss.

Schneider adds that growers that view field drying as a secondary form of storage —  thereby reducing storage fees — then the total of drying and storage costs should be combined and compared to the percent yield loss through winter.

Another option is rather than leaving the crop stand in the field until the following spring, which can create problems preparing for the next crop, the grower might consider harvesting sometime in midwinter.

Data from the Arlington, Wis., research station gathered over five winters found mid-May planted corn had the following grain moistures: December 22%; January 22%; February 18%; March 16%; and April 10%.

"Drying continues through winterm but at a slower rate than fall," Schneider says. "Unfortunately, it's difficult to predict in October if there will be heavy snowfall or ice sheeting come January, so the decision largely becomes a matter of risk management.

Schneider adds that the 2009 corn crop was one of the most expensive corn crops ever grown and the financial losses from a large yield decline could be large. Once the grain is harvested, dried and securely stored, the harvest risk largely has been managed.