SINGAPORE  - Chicago soybeans slid 2 percent on Tuesday to their lowest since March 2016, while corn dropped for a fifth consecutive session on concerns over a deepening trade war between Washington and Beijing.

Wheat lost more ground on pressure from the rapidly expanding U.S. winter crop harvest.

"China has set higher tariffs on U.S. beans which means Brazil will grab a bigger share of the Chinese markets," said Phin Ziebell, agribusiness economist at National Australia Bank.

"At the same time we are seeing very good crop weather in much of the U.S. Midwest."

The Chicago Board of Trade most-active soybean contract dropped to a low of $8.87-1/2 a bushel, the weakest since March 2016. It was trading down 2.1 percent at $8.89-1/2 a bushel by 0327 GMT.

Corn slid 2 percent to $3.49 a bushel, the lowest since January and wheat fell 0.7 percent to $4.86-1/2 a bushel.

U.S. soybeans are set to lose market share in China, the biggest bean importer, as trade tensions escalate between the two nations.

U.S. President Donald Trump last week announced hefty tariffs on $50 billion in Chinese imports, and China hit back, announcing 25 percent tariffs on 659 U.S. goods, including soybeans, starting July 6.

China's most-active soymeal futures rose as much as 5 percent to 3,095 yuan a tonne as the market opened after Beijing's move to slap 25 percent import duty on soybean from the United States.

There is additional pressure on corn and soybean prices from crop-friendly weather across the U.S. Midwest which is boosting crops.

After market hours on Monday, the U.S. Department of Agriculture said 78 percent of the corn crop was in good to excellent condition as compared with 77 percent a week ago and above last year's 67 percent.

For soybeans, the agency said 73 percent of the crop was in good to excellent condition versus 74 percent a week ago and 67 percent at the same time last year.

Brazil's soybean trading has practically ground to a halt as uncertainty over freight costs has kept buyers and sellers at bay despite expectations of stronger sales after an escalation of the U.S.-China trade fight, brokers and farmers said on Monday.

Commodity funds were net sellers of CBOT corn, wheat and soymeal futures contracts on Monday and net buyers of soybeans and soyoil, traders said.

(Reporting by Naveen Thukral; Editing by Sunil Nair)

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