McLean County yields below 5-year average

BLOOMINGTON, Ill. — The yield average in the Prairie State’s top corn-producing county is estimated to be the lowest in five years.

First Mid Ag Services released its 30th annual McLean County corn yield estimates, based on 1,570 samples from 157 locations of managed farms, representing every township. Ten farm managers from the firm conducted the survey.

McLean County’s average corn yield is estimated at 212.39 bushels per acre, down from the five-year average of 230.02.

According to the U.S. Department of Agriculture, the county averages the previous five years were: 205.7 in 2021, 232.2 in 2022, 223.3 in 2023, 246.7 in 2024 and 243.1 in 2025.

Sample yield estimates ranged from 153.75 to 268.80 bushels per acre.

The survey noted 71% of the locations returned a yield estimate over 200 bushels per acre, compared to 89% in 2024 and 94% in 2025.

The majority of the samples were taken before the Aug. 16 storms.

The number of kernels around was 15.65, compared to the previous five-year average of 16.45. Meanwhile, the average kernel length was 31.69 compared to the previous five-year average of 34.13.

The average number of kernels per bushel used was 80,070 in 2026.

“The crop benefited from strong emergence, above-average plant and ear populations and generally good plant health, but weather limited yield potential,” the survey, led by Michael Rhoda, First Mid Ag Services farm manager, said.

“Excessive June rainfall and saturated soils were followed by above-normal July heat and below-normal rainfall, while August storms brought additional wind damage and concerns about harvestability.

“Reduced kernel rows per ear and shorter kernel length indicate that kernel development and fill were the primary factors limiting yield.

“With 71% of sampled locations estimated above 200 bushels per acre, the 2026 crop was not a poor crop overall, but it fell short of the exceptional yields seen across McLean County in recent years.”

The survey also provides a look back at the growing season thus far and its impact on corn yield potential.

Weather

The county’s median planting date was May 9, later than the five-year average. Samples ranged from April 21 to May 20.

There were fewer fields planted in April, 56 counts, than May, 101 counts. April-planted corn estimated a roughly 6-bushel advantage versus May-planted corn.

Growing season weather varied in extremes. June was the fifth wettest on record for Illinois, with overly saturated soils negatively affecting top end yield potential.

Meanwhile, July was above normal for heat with below-normal rainfall, helping fields dry out.

There was above average rainfall and significant winds in Bloomington and east-southeast in the county during August.

Emergence

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

Final ear populations of approximately 34,400 ears per acre were measured, which was above the five-year average of about 33,076 ears per acre.

The average plants per acre counted were estimated at 35,070, compared to the five-year average of approximately 33,800 plants per acre.

Fungicide Application

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

This year, 89% of samples received a fungicide, slightly less than the 91.4% sprayed last year. While pulling checks, disease pressure was noticed in both sprayed and not sprayed fields.

Tar spot, gray leaf spot and anthracnose were noted, but not severe at the time of sampling.

Standability

Plant health was a non-issue throughout most of the season. The county’s average stalk quality rating is 8.64 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 we move 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,” the report said.

Other Conclusions

The county corn yield estimates report concluded with the following notes:

• The crop had noticeable tip-back across the county.

• Disease pressure has shown up later and will be monitored to recognizes its effect on final yield.

• Wind damage from storms will negatively affect harvestability.

• Weather until harvest will play a big factor in determining kernel weight.