Sponsored By
indiana Prairie Farmer Logo

Will corn in field still dry down in late fall?Will corn in field still dry down in late fall?

Corn Illustrated: Here’s what you can expect from natural drying in late fall.

Tom J. Bechman

October 31, 2023

3 Min Read
a dried-down cornfield with windstorm damage
HARVEST NOW: This picture speaks for itself. This cornfield was a tangled mess after a mid-November windstorm. Tom J. Bechman

Word in many localities is that corn tended to dry down slower this fall. That means higher moisture levels if you harvest, and more time spent drying corn. The natural temptation is to leave it in the field. If you still have corn in the field today, how much more help can you expect from Mother Nature?

“Based on history, the answer would be little to no additional help now,” says Dave Nanda, director of genetics for Seed Genetics Direct. “Once the calendar hits November in most years, corn doesn’t dry down much more in the field. On the other hand, the risk for windstorms and snow that could lead to harvest loss increases. My inclination would be to wrap up harvest as soon as possible.”

What experts say about drydown

Nanda isn’t the only one who has reached this conclusion. Here’s a brief look at opinions from several corn specialists across the Midwest:

Ohio State. Peter Thomison, longtime Ohio State University Extension corn specialist, now retired, penned an article in 2019 after very late planting pushed back corn maturity.

“Once corn achieves physiological maturity, it will normally dry approximately 0.75% to 1% per day during favorable drying weather (sunny and breezy) during the early warmer part of the harvest season from mid‑September through late September,” he wrote. “By early to mid‑October, drydown rates will usually drop to 0.5% to 0.75% per day. By late October to early November, field drydown rates will usually drop to 0.25% to 0.5% per day, and by mid-November, probably zero to 0.25% per day. By late November, drying rates will be negligible.”

Iowa State. Corn matured slowly in 2017, somewhat like this year. Mark Licht, Iowa State University Extension specialist, advised farmers what to expect in this article: “The rule of thumb has been that corn dries at a rate of 0.5% to 1% per day in September, and 0.25% to 0.5% per day in October, with almost no drying occurring in November. Of course, these rules of thumb can change with favorable or unfavorable weather conditions.”

More recently, Iowa State University developed a corn drydown calculator. Pull up the site and map, select anywhere shown across the Midwest, and in seconds, you see a graph showing drydown rates to expect through the rest of fall.

Purdue. Bob Nielsen, Purdue Extension corn specialist, now retired, laid out how corn kernels lose moisture, and noted they lose it less rapidly after a certain point, in this 2018 article: “Grain moisture loss in the field occurs at a fairly linear rate within a range of grain moisture content from about 40% down to 15% to 20%, and then tapers off to little or no additional moisture loss after that,” Nielsen wrote. “The exact rate of field drying varies among hybrids and years.”

He added a cautionary note. Average drydown rates are just that — averages. “It is not uncommon for grain moisture to decline more than 1 percentage point per day over a period of days when conditions are warm, sunny, windy and dry,” he wrote. “In contrast, there may be zero drydown of grain on cool, cloudy, rainy days.”

Read more about:

Dry Down

About the Author(s)

Tom J. Bechman

Editor, Indiana Prairie Farmer, Farm Progress

Tom J. Bechman is editor of Indiana Prairie Farmer. He joined Farm Progress in 1981 as a field editor, first writing stories to help farmers adjust to a difficult harvest after a tough weather year. His goal today is the same — writing stories that help farmers adjust to a changing environment in a profitable manner.

Bechman knows about Indiana agriculture because he grew up on a small dairy farm and worked with young farmers as a vocational agriculture teacher and FFA advisor before joining Farm Progress. He works closely with Purdue University specialists, Indiana Farm Bureau and commodity groups to cover cutting-edge issues affecting farmers. He specializes in writing crop stories with a focus on obtaining the highest and most economical yields possible.

Tom and his wife, Carla, have four children: Allison, Ashley, Daniel and Kayla, plus eight grandchildren. They raise produce for the food pantry and house 4-H animals for the grandkids on their small acreage near Franklin, Ind.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like