Crop tour finds strong corn, soy potential along with diseases in Illinois, western Iowa

Spencer, Iowa | Reuters — Corn yield potential and soybean prospects are significantly above average across Illinois and western Iowa, though plant diseases could threaten final yields, scouts on an annual crop tour of the Midwest said on Wednesday.

The four-day Pro Farmer crop tour, which started on Monday and covered seven major corn and soybean states, found strong production potential so far. Grain market participants have been monitoring the tour’s findings to gauge the size of the 2025 harvest in the United States, the world’s largest corn exporter and No. 2 soybean supplier.

Above-average Illinois soy potential

The tour, which does not project soybean yields, estimated the number of soybean pods in a 3-by-3-foot square in Illinois, the top soy-producing state, at an average of 1,479.22, above last year’s tour average of 1,419.11 pods and the highest in tour records, which date back to 2003.

The tour projected the Illinois corn yield at 199.57 bushels per acre (bpa), down from 204.14 bpa in 2024, but the second-highest on tour records.

In Iowa’s western third, the tour’s corn yield forecasts and soybean pod counts were well above the three-year averages. It will release full statewide figures for Iowa on Thursday.

Rust, fungal issues

Timely rains benefited crops in western Iowa but also promoted the growth of fungal diseases such as southern rust in corn and sudden death syndrome in soybeans, which tend to lower crop yields.

“I think we’ve lost 10 per cent of the yield due to disease,” Roger Cerven, an Iowa farmer who is on the tour, said of sudden death syndrome in soybeans.

For corn, southern rust was so widespread in some Iowa fields that scouts emerged with sleeves covered in dusty orange-colored residue from rust spores on corn leaves.

The extent of any impact of diseases on yields won’t be fully known until crops are closer to harvest, scouts said, but some effects may emerge sooner.

“The crop, I think, is going to look a whole lot different in 10 days or two weeks than what it does right now,” said Chip Flory, one of the tour’s leaders.

Roughly 100 crop scouts are on the tour, which wraps up in Rochester, Minnesota, on Thursday. The editors of Pro Farmer, a newsletter, will release their own estimate of U.S. corn and soybean production on Friday.

—1 acre = 0.405 hectares