WASHINGTON — The U.S. Department of Agriculture’s September World Agricultural Supply and Demand Estimates report issued Sept. 12 included bearish surprises for wheat and corn.

In the case of wheat, the surprise came in the U.S.D.A.’s world supply-and-demand forecasts, as there were no changes to the 2018-19 domestic all-wheat outlook. The U.S.D.A. forecast 2018-19 world wheat ending stocks at 261.29 million tonnes, up 2.33 million tonnes from the August projection but down 13.07 million tonnes, or 5%, from a record 274.36 million tonnes in 2017-18. Pre-report trade estimates averaged 257.58 million tonnes. World wheat production in 2018-19 was forecast at 733 million tonnes, up 3.37 million tonnes from August but down 25.27 million tonnes, or 3%, from a record 758.27 million tonnes in 2017-18.

As expected, the U.S.D.A. lowered its production forecasts for Australia (down 2 million tonnes) and Canada (down 1 million tonnes), but it unexpectedly raised its estimate for Russian wheat production by 3 million tonnes, to 71 million. With the Russian crop larger than expected, the U.S.D.A. held its export forecast for Russian wheat in 2018-19 at 35 million tonnes.

In corn, the surprise was a larger-than-expected increase in average corn yield, which had ripple effects across the domestic corn supply-and-demand balance sheet. The U.S.D.A. forecast the average corn yield at an astounding and record 181.3 bus per acre, up 2.9 bus from 178.4 bus per acre as the August forecast.

The higher yield forecast prompted the U.S.D.A. to raise its projection for the 2018 crop to 14,827 million bus, up 214 million bus from the August outlook. Given the larger forecast supply, the U.S.D.A. raised its forecast for 2018-19 feed and residual use of corn by 50 million bus, to 5,575 million, its food, seed and industrial use of corn forecast by 25 million bus, to 7,130 million, and its exports forecast by 50 million bus to 2,400 million.

Despite the larger disappearance forecasts, the U.S.D.A. projected the carryover of corn on Sept. 1, 2019, at 1,774 million bus, up 90 million bus from August and compared with 2,002 million bus in 2018.