DEER CREEK, Ill. – Illinois’ corn yield will average just 189.4 bushels per acre at harvest, according to results from the 2020 Pro Farmer Midwest Crop Tour. That estimate, which takes into account the effects of the Aug. 10 derecho and recent near-drought conditions, comes in far shy of the 207 bushels pre-derecho USDA projection for the 2020 Illinois corn yield.

Pro Farmer’s projections came in lower than those of USDA’s Aug. 1 report in every state save South Dakota. Pro Farmer is projecting average corn yields in Indiana at 179.8, Iowa at 177.8 and Ohio at 167.6.

Independent crop yield tours were taking place throughout Illinois in early August. In central Illinois, known as home to some of the richest soil in the world, Bell Enterprises released a dual-scenario for corn yield based on kernels per bushel.

“Industry standard for estimating yield includes a factor of 90,000 kernels per bushel assumption,” said Kim Craig, grain merchandiser for Bell Enterprises, whose elevators serve farmers in Woodford, Tazewell and McLean counties. Corn and soybean yields in those counties are routinely among the highest in the nation.

“We have a similar to last year kernel weight based on the average ear weights divided by average kernel count per ear,” Craig said. “Based on that observation I have adjusted the factor in the calculation to 82,000 kernels per bushel from 90,000.”

Bell’s 106 scorecards recorded an average yield of 192.57 (raw yield at 90,000 seeds per acre) with an adjusted yield of 211.36 (82,000 seeds). This final adjusted yield comes in 3 bushels per acre below the 2019 actual yield of 214.71, a 1 percent decrease. The adjusted yield will be 5.4 percent less than the five-year actual yield of 223.32. 

In addition, Bell found that the kernel count per ear, at 550 kernels, is five below the five-year average of 554 kernels per ear due to average smaller ear size. “There is some minor tipping back of the ears in the late planted corn. The later planting,  better populations in the late planted corn and July heat this year may be some of the reason for the minor tipping back,” Craig said. 

Fifty-eight percent of the Bell tour participants rated the early planted corn as the best. Ninety-two percent of the tour participants concluded that the crop would not be mature (black layer) by Sept. 1. Ninety-two percent of participants also agreed that additional rains would add yield to the crop.

“While seeding rates were mostly unchanged, again difficult spring seeding conditions resulted in slightly less plant populations overall,” Bell added. “Approximately 35 percent of the crop was planted in April and resulted in some average ear populations in those field checks. We recorded a 31,590 average ear population, which is 480 less population than last year and 560 less than the five year average. We found more smut (fungal disease in grains) this year than usual.”

The DTN/Progressive Farmer 2020 Digital Yield Tour determined average corn yields for Illinois at 200.3 bushels, 7 bushels below USDA’s estimate. The tour projected Indiana corn at 190.4, above USDA’s 188 and pegged Ohio at 175.8, just above USDA’s prediction of 175. “If true, the tour’s estimated yields would be new state records for Indiana and Ohio, two states that looked in trouble earlier this season,” DTN Lead Analyst Todd Hultman said.

DTN’s tour is powered by Gro Intelligence, which uses real-time yield maps, generated with satellite imagery, rainfall data, temperature maps and other public data, to take an in-depth look at corn and soybean progress. While neither Gro nor USDA’s estimates incorporated the impact of the Aug. 10 Midwest derecho, it is increasingly clear that the storm system rolled over some of the region’s most promising fields, noted DTN farm business editor Katie Dehlinger.