McLean corn survey estimates yields above five-year average

BLOOMINGTON, Ill. — McLean County corn yields are estimated to be above the five-year average for the second straight year.

First Mid Ag Services in its 29th annual yield survey of McLean County corn estimates an average of 233.9 bushels per acre, 11.96 bushels above the five-year average.

The yield estimate is based on 1,510 samples from 151 locations taken on managed farms from every township in the county by 10 First Mid Farm managers.

Sample yield estimates ranged from 177.02 bushels per acre to 288.87 bushels per acre.

The county averaged 246.7 bushels an acre in 2024, according to the U.S. Department of Agriculture.

Ninety-four percent of the locations returned a yield estimate over 200 bushels per acre, compared to 89% in 2024 and 88% in 2023.

A majority of the samples used for this estimate were taken the second week of August.

The number of kernels around was 16.24 compared to the previous five-year average of 16.52. Meanwhile, the average ear population was 33.62 compared to the previous five-year average of 32.41.

The average number of kernels per bushel used was 80,100 in 2025. Hot and dry conditions in August may affect the final kernel weight.

“The crop was fairly consistent across the wide geography of the county. Disease pressure has shown up later and will be monitored to recognize its effect on the final yield. The weather until harvest will play a big factor in determining kernel weight,” the survey concluded.

The survey also documented various other aspects of the McLean County yield story.

Weather

Adequate soil moisture and above-normal temperatures allowed the crop to grow very quickly in June. Timely rains continued until the end of July.

Small pockets of wind damage from summer thunderstorms were observed throughout McLean County.

August temperatures have been above normal with more spotty showers.

Planting Dates

Planting dates in 2025 were earlier than the five-year average. There were fewer fields planted in May, with 37 counts, than April, with 114 counts.

Planting dates for the samples taken ranged from April 16 through May 29, with an average planting date of April 29.

The April-planted corn estimated a roughly 7 bushel advantage — 235.6 versus 228.7 — in yield estimate versus May-planted corn.

Emergence

With a majority of the farms getting planted into good soil conditions, plant emergence was good.

Final ear populations of about 33,600 ears per acre were measured, which was above the five-year average of about 32,400 ears per acre.

The average plants per acre counted were about 34,400 compared to the five-year average of about 33,400 plants per acre.

Fungicide Application

Each year, the yield survey tracks samples sprayed with fungicide. Application typically occurs during the R1 timeframe between tassel and brown silk.

This year, 91.4% of samples received a fungicide, slightly less than the 93.6% sprayed last year.

While pulling checks, very little disease pressure was noticed in both sprayed and not-sprayed fields. Tar spot, gray leaf spot and rust were noted, but were not severe at the time of sampling.

Standability

Plant health was a non-issue throughout most of the season. The average stalk quality rating was determined to be 8.88 on a scale from 1 to 10.

There were very small pockets of green snap and lodging, especially where there were heavy amounts of wind and rainfall in McLean County.

As the corn moves toward harvest, stalk qualities should be monitored with the possibility of tar spot and other diseases to have a negative effect on stalk quality and kernel weight.