CHICAGO - U.S. soybean futures plunged 1.5 percent to a one-year low on Friday on concerns that escalations in a trade fight with China would threaten shipments to the biggest buyer of the oilseed, traders said.

U.S. President Donald Trump announced hefty tariffs on $50 billion of Chinese imports on Friday, with collection beginning on July 6. China said it plans to impose tariff measures of a similar size and intensity in its bid to fight back.

China has published a list of threatened tariffs on $50 billion in U.S. goods, including soybeans, aircraft, and autos, and said it would hit back if Washington followed up with further measures.

"We've spent much of the last couple months expecting this to be saber-rattling and something that would be resolved far before actual action takes place," said Angie Setzer, vice president of grain at Citizens LLC, a grain elevator in Michigan. "But here we are."

Trade concerns also weighed on the corn market as Mexico could strike at $4 billion in annual imports of U.S. corn and soybeans if Trump escalates a trade spat with new tariffs, officials told Reuters this week.

Corn futures sank to their lowest in more than five months overnight before rebounding on bargain buying.

At 8:52 a.m. CDT (1352 GMT), Chicago Board of Trade soybean futures for July delivery were down 12-3/4 cents at $9.14-1/2 a bushel.

Prices for the front-month contract bottomed out at $9.03 a bushel, the lowest since June 23, and threatened to fall below the key $9 a bushel threshold for the first time since March 31, 2016.

Soybean futures have fallen for eight of the previous nine sessions as the rhetoric between China and the United States has heated up. Prices for the November contract have shed more than $1 a bushel since the start of the month, threatening profitability on the crop that farmers will harvest this fall.

CBOT July corn futures were up 2-1/2 cents at $3.65-1/2 a bushel but on track to post a weekly loss of 3.4 percent, which would be the third straight weekly decline.

Forecasts for good weather around the U.S. Midwest added to the pressure on corn and soybean futures as crops near key development phases.

CBOT soft red winter wheat futures also were caught in the sell-off, with the July contract down 4 cents at $4.97-1/2 a bushel.

The dollar index hit a seven-month high on Friday, providing a rationale for investment funds looking to liquidate their bullish bets on wheat. (Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; editing by Subhranshu Sahu, Jason Neely, Jeffrey Benkoe)

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