Corn prices have climbed to a three-year peak, driven by reduced US production forecasts and persistent geopolitical friction in the Black Sea region, which together have fueled concerns over global supply availability.

Chicago's most-active corn futures contract jumped as much as 2.7% to $5.22 per bushel, marking the highest intraday level since early August 2023. Data from last Friday's Pro Farmer crop tour indicated that harvest expectations across several states are running below earlier projections, prompting traders to reassess this season's output potential. Pro Farmer now estimates US corn production at 15.34 billion bushels, with an average yield of 173.2 bushels per acre—a figure that trails the US Department of Agriculture's prior forecast of roughly 16 billion bushels.

"Corn is benefiting from a strong bullish impulse driven by the Pro Farmer crop tour data," said Joe Davis, commodity sales director at Futures International LLC. The tightening outlook for US supplies has intensified market anxiety over potential disruptions in the Black Sea, a critical export corridor for both corn and wheat.

Over the weekend, Ukrainian President Volodymyr Zelensky stated that Kyiv had proposed a ceasefire arrangement with Moscow to safeguard grain-carrying vessels from attacks in the region, but Russia declined the offer. As Ukraine stands as a major exporter of corn and wheat, any further strikes on shipping routes or infrastructure could severely hamper supply flows while pushing freight and insurance costs higher.

In parallel, Chicago wheat futures advanced as much as 2% to $7.13 per bushel on Monday, reaching the highest intraday level since May 2024. Still, ample global stockpiles are likely to cap further upside in the market.