Corn Height Variable

Posted: July 17, 2023

Later-planted corn shorter than early-planted corn based on shortfall of precipitation

The height of corn has been greatly limited in many areas of the state by the severe lack of moisture so far this season, including DeKalb County.

The majority of the state (92.7%) was in drought, according to the latest U.S. Drought Monitor released June 29, while the remainder, mostly in southern Illinois, was rated abnormally dry.

Most of the northern two-thirds of the state was in severe drought as of June 27.

“We’ve been drier since planting than 1988 or 2012,” said Lance Tarochione, DeKalb/Asgrow technical agronomist. “Things don’t look good.”

“If you have early-planted corn on good soil, it’s held up the best,” he noted. “But, if you have later-planted corn, corn on lighter soils or compacted soils, that stuff looks pretty tough. There’s lots of scary-short corn and lots of nutrient deficiency symptoms.”

But, while much of this year’s corn crop may not grow to the height of a professional basketball player, many farmers can still score some respectable yields if the recent return of regular showers continues.

“There’s a lot of concern about height. There’s going to be a lot of corn six feet tall fully tasseled,” Tarochione said. “And, it’s not going to grow much after it tassels.

Farm girls taller than this corn
These farm girls show their own height exceeds the height of this field of later-planted corn. In early July, (from left) Blake Benson, Finley Wassmann, and Berkley Benson stood by the four-foot corn plants in a field near Waterman. The girls proved the corn was more than knee-high by the fourth of July, based on their knees! Blake, 7, and Berkley, 5, are the daughters of Wade and Carson Benson. Finley, 6, is the daughter of Matt and Mallory Wassmann.

“But there’s really no correlation between height and yield, although there is some correlation with leaf area and yield (which can affect sunlight capture and photosynthesis),” the agronomist noted.

Just 26% of the corn crop and 25% of soybeans were rated good to excellent statewide as of June 26, down dramatically from 70% and 66%, respectively, as of the same date last year.

The key, of course, is the weather pattern for the upcoming pollination season.

“The height of corn is determined in June, but the corn yield is determined in July,” Tarochione said. “This crop still has far more potential than crop insurance levels, but we need a lot of rain soon. If there’s not much rain soon, then it won’t pollinate well and there could be a lot of kernel abortion.”

Soybean growth also remains limited, although that crop has more time to recover this season as yield potential isn’t usually set until August, the agronomist noted.

Rainfall activity increased in the state the last week of June with more forecast off and on in early July.

Moisture deficits reached eight to 10 inches in much of the state through late June, according to Trent Ford, state climatologist with the Illinois State Water Survey. Statewide, topsoil ranked 89% short to very short as of June 26.

Source: FarmWeek