By Jesse Newman

CHICAGO--Wheat futures sank Wednesday amid forecasts for better weather in the U.S. Plains, where much of the nation's crop is grown.

Corn and soybeans also declined.

Prices for wheat slid nearly 2% as traders eyed forecasts for rainfall to douse the U.S. wheat belt over the weekend, reducing dryness there and potentially benefiting winter crops which are in their dormant phase.

Pessimism in the wheat market was amplified by expectations that the U.S. Department of Agriculture in a monthly report Thursday will forecast domestic wheat stockpiles at the end of the current season next May at a 29-year high, reflecting an ongoing glut of grain. Still, analysts saidwheat prices could get a boost from another report due out the same day expected to show U.S. farmers likely seeded the fewest acres of winter wheat in over a century this season.

Wheat futures for March delivery dropped 8 cents, or 1.9%, to $4.18 3/4 a bushel at the Chicago Board of Trade.

Corn and soybean prices eased amid expectations that the USDA on Thursday will report stockpiles at the beginning of last month hit all-time records, following the biggest-ever hauls of the crops brought in by U.S. farmers last summer.

Analysts widely expect the USDA to report corn inventories on Dec. 1 at 12.358 billion bushels, almost 10% more than a year earlier. Soybean reserves on the same date likely totaled 2.951 billion bushels, up nearly 9% from the year prior, analysts said.

CBOT January soybean futures fell 2 1/2 cents, or 0.3%, to $10.03 a bushel.

Uncertainty in global export markets added to bearish sentiment in the corn market. Analysts said China had raised tariffs on imports of U.S. dried distillers' grains, an ethanol by-product used in animal feed, for a period of five years.

The move, which will hamper exports of the ingredient, casts more doubts over trade disputes with China just as President-elect Donald Trump prepares to take office. Mr. Trump has been sharply critical of China's trade policies.

"There are building concerns this may just be the start of a trade war between the two countries," said Karl Setzer of MaxYield Cooperatives.

CBOT March corn slid 1 cent, or 0.3%, to $3.57 1/4 a bushel.

Write to Jesse Newman at jesse.newman@wsj.com

(END) Dow Jones Newswires

January 11, 2017 15:59 ET (20:59 GMT)

Copyright (c) 2017 Dow Jones & Company, Inc.