Corn futures for December-25 tumbled by 3.7% in Chicago to a contract low, weighing on wheat prices too, after the USDA in its benchmark Wasde report hiked its forecast for the US corn harvest this year by nearly 20Mt more than the market had expected.

The upgrade reflected increases to estimates for both yield and area.

Wheat futures for September-25 shed 2.2% in midday deals in Chicago, also setting a contract low, despite some modest reductions to key indicators for world supplies.

The fall dragged London November-25 futures down 1.3% to their first close below £170/t, while Paris wheat for September-25 settled down 1.0%, also at a contract closing low.

Soybean futures for November-25 bucked the trend, adding 1.3%, after the USDA made a surprise downgrade to the US harvest forecast.

The rise helped rapeseed futures recover some lost ground, after tumbling earlier on a Chinese announcement of a preliminary tariff on imports of Canadian canola, which itself traded 4.6% lower.

Paris rapeseed for November-25 settled down 1.5% at a four-month closing low.

Important revisions in the Wasde are detailed below.

Corn

For corn, the USDA lifted its estimate for this year’s US yield by 0.49t/ha to 11.85t/ha – above even the expectation of the most upbeat forecaster. The upgrade to even further above the existing record of 11.26t/ha, set last year, was the department’s first of the year based on actual crop surveys.

With the area figure expanded by 1.9M acres too, “based on a thorough review of all available data”, the production forecast was upgraded by 26.3Mt to 425.3Mt, also a record high.

While the US corn export forecast was raised by 5.1Mt to an all-time high of 73.0Mt, “reflecting U.S. export competitiveness and expectations of relatively low world market prices”, and the estimate for use in livestock rations raised too, the bumper crop nonetheless fed through into an increased figure for 2025/26 carryout stocks, of 53.8Mt.

That represented an upgrade of 11.6Mt from last month’s figure, and of 20.6Mt year on year, and would be the highest US corn inventory figure in seven years.

At a global level, the corn stocks estimate was raised by 10.4Mt to 282.5Mt, some 3Mt ahead of market expectations, and factoring in modest cuts to inventories in the EU, for which the harvest outlook was cut by 2.0Mt to 58.0Mt, and China.

The estimate for Brazil’s 2024/25 corn output, including the ongoing safrinha corn harvest, was held at 132.0Mt.

Soybeans

For soybeans, the USDA raised its US yield forecast too by more than traders had expected, by 0.07t/ha to a record 3.60t/ha, although the figure remained within the range of market expectations.

However, the harvest was downgraded by 1.2Mt to 116.8Mt nonetheless, as the USDA put the gain in corn area down to soybeans’ expense.

Although the forecast for US exports was trimmed by 1.1Mt to 46.4Mt, based on the “lower supply and the slow pace of export sales to date”, the estimate for US stocks at the end of 2025/26 was reduced nonetheless by 550Kt to a three-year low of 7.9Mt. The market had expected an upgrade in the stocks forecast, to 9.8Mt.

The revisions were reflected in a 1.2Mt downgrade to 124.9Mt in the forecast for world soybean stocks at the close of 2025/26, representing a small reduction year on year – the first inventory decline after four seasons of growth.

Wheat

The USDA left its estimate for this year’s US wheat harvest little changed at 52.5Mt.

However, with the export forecast lifted by 800Kt to 23.8Mt, “on the continued strong early pace of sales and shipments, particularly for hard red winter [wheat],” the forecast for the US wheat carryout was cut by 590Kt to 23.6Mt.

Elsewhere, the EU harvest was upgraded by 1.0Mt to 138.3Mt. However, this was more than offset by reductions to output in Argentine, by 300Kt to 19.7Mt, in Brazil, by 500Kt to 7.5Mt and in China by 2.0Mt to 140.0Mt.

The world wheat stocks forecast was trimmed by 1.4Mt to 260.1Mt, contrary to market expectations of a small upgrade to 261.7Mt.

This reduction factored in a 1.5Mt cut to inventories in the top seven exporters, to a five-year low of 58.8Mt.

The USDA held its estimates for 2025/26 UK wheat supply and demand, including leaving its harvest figure at 12.5Mt.