By DANIEL GRANT

FarmWeek

After an unseasonably cool start to the grain fill period, a blast of hot air the final week of August kicked the crop maturation process into overdrive.

The National Agricultural Statistics Service reported 10 percent of the corn crop was mature and 62 percent was dented in Illinois as of Aug. 26, which was ahead of the average pace by 7 and 15 points, respectively.

Meanwhile, 93 percent of soybeans were setting pods and 6 percent were dropping leaves as of the same date, both well ahead of the average pace across the state.

“Corn has had a pleasant grain fill period, but the 90-(plus)-degree temperatures will speed up maturity,” Karen Corrigan, an agronomist with McGillicuddy-Corrigan Agronomics, noted in a recent ILSoyAdvisor report.

Temperatures in Illinois averaged just 68.7 degrees (4.6 degrees below normal) Aug. 19-26 but heated up well into the 90s with triple-digit heat index readings in many parts of the state to close the month.

“Temperatures this (past) week could push that (crop maturation) along rapidly,” said Jeff Guilander, a FarmWeek CropWatcher from Jersey County. “Soybeans are getting a yellow tone as they begin to mature.”

Guilander believes harvest in his area could begin near or just after Labor Day weekend as crops continue to progress rapidly. Temperatures were expected to moderate by that time. Other farmers look for harvest to begin later this month around the state.

Champaign County CropWatcher Daniel Herriott reported a similar situation in his area.

“The early maturing corn that was planted in early April is racing to the finish line,” he said.

The recent run of hot, dry weather could also slow the spread of some crop diseases, particularly tar spot, according to Corrigan. She advised farmers to note weed escapes to consider for 2025 cropping plans.

But the recent heat and dryness could have a negative impact on some crop yield potential, depending in part on planting dates and previous weather.

“Variation in fields is dramatic as the stressed areas really stand out,” Guilander said.

Some areas of the state received rainfall at the peak of the heatwave Aug. 27, including small pockets that received two-plus inches.

Overall, topsoil moisture was rated 61 percent adequate, 38 percent short to very short and just 1 percent surplus statewide as of Aug. 26. 

All or parts of 12 Illinois counties in the northeast were rated abnormally dry, according to the U.S. Drought Monitor.

This story was distributed through a cooperative project between Illinois Farm Bureau and the Illinois Press Association. For more food and farming news, visit FarmWeekNow.com.