Corn Prices Ease as Wheat and Soybean Markets Send Mixed Supply Signals

US corn futures retreat

US corn futures ended lower on Tuesday, August 18, 2026, even as field data pointed to weaker crop conditions and below-average yield potential in two major producing states. September corn settled at $4.63-1/4 per bushel, down 1 3/4 cents. December closed at $4.88, down 1 1/2 cents, while March finished at $5.04, a decline of 1 1/4 cents, according to ZOL.ru.

The ProFarmer Crop Tour estimated average corn yield in South Dakota at 149.09 bushels per acre, 14.41% below last year and 8.37% under the three-year average. Ohio yielded an estimated 180.18 bushels per acre, down 2.97% year on year and 2.25% below its three-year average. Results for Indiana and Nebraska had yet to be released.

US crop ratings also deteriorated. The share of corn rated good or excellent fell to 60%, one percentage point below the previous week and 11 points below the prior-year level. The weaker indicators have not yet reversed pressure on nearby futures, while overseas supply remains substantial. ANEC raised its estimate for Brazilian corn exports in August to 5.63 million tonnes, 0.46 million tonnes above its estimate a week earlier.

Wheat prices diverge by class and delivery

Wheat trading was mixed across US classes. September Chicago soft red winter wheat fell 10 1/4 cents to $6.64-1/2 per bushel, and December lost 8 cents to $6.81-1/4. Kansas City September hard red winter wheat dropped 15 cents to $7.43-3/4, while December declined 13 1/4 cents to $7.58-1/2. Minneapolis spring wheat moved in the opposite direction: September gained 1 1/4 cents to $6.76-1/4 and December added 3/4 cent to $7.04-3/4.

USDA NASS data showed 52% of the spring wheat crop rated good or excellent, one percentage point higher than a week earlier. By August 16, growers in the six leading states had harvested 41% of spring wheat, compared with 33% on the same date in 2025. Winter wheat harvesting was 96% complete in 18 key states, up from 91% a week earlier and 93% a year before.

European trade supplied a contrasting signal. European Commission data put EU soft wheat exports from July 1 to August 16 at 1.48 million tonnes, down 49% from 2.9 million tonnes in the corresponding period a year earlier. The leading exporters were Lithuania, Romania, Bulgaria, Germany and Poland; major buyers included Nigeria, Algeria, Indonesia, Saudi Arabia and Vietnam. On MATIF, September milling wheat fell to €223.25 per tonne, while December rose to €235.75.

Soybeans balance Chinese demand and Brazilian supply

Soybean futures surrendered intraday highs and finished close to unchanged. September settled at $12.00-3/4 per bushel, down 1/4 cent. November added 3/4 cent to $12.16-3/4, and January gained 1/2 cent to $12.31-1/2. USDA reported a private sale of 136,000 tonnes of US soybeans to China for the 2026/27 season.

Crop indicators were less supportive. The good-to-excellent rating for US soybeans fell one percentage point to 61%. ProFarmer counted 945.98 pods in a 3-by-3-foot area in South Dakota, 20.4% below last year and 12.07% below the three-year average. Ohio’s count was 1,197.25, down 6.99% year on year and 4.74% below the three-year average. ANEC estimated Brazilian soybean exports at 10.56 million tonnes, 0.32 million tonnes below its previous weekly estimate, leaving traders to weigh softer US crop data against continued competition from Brazil.