Corn futures fell below $5.10 per bushel, pulling back from an over three-year high of $5.21 hit on September 1, as traders adjusted positions ahead of Friday’s widely anticipated USDA supply-and-demand report. The decline came despite expectations for weaker US yields, which have continued to provide a floor for prices. Commodity brokerage StoneX lowered its estimate of the average US 2026 corn yield to 182.9 bushels per acre from 184.8 in its previous monthly forecast, raising concerns over tighter supplies. Meanwhile, warmer and drier weather across the US Midwest in the coming weeks is expected to limit harvest delays and reduce frost risks, potentially allowing fieldwork to progress quickly. The USDA reported that 5% of the US corn crop had been harvested as of last Friday, while 56% was rated good to excellent. Traders are also watching risks to Black Sea grain exports as the ongoing Russia-Ukraine war threatens to disrupt supplies and tighten global grain markets.