CHICAGO: US corn and soybean futures eased on Tuesday as better-than-expected rain in parts of the Midwest and forecasts for more showers lessened concerns about further yield losses in dry areas of the farm belt.

Wheat futures declined as pressure from an advancing US harvest and a firmer US dollar dragged down prices and triggered technical selling.

Fears of a prolonged US-China trade war hung over grain markets a day after the US Treasury Department branded China a currency manipulator.

US President Donald Trump on Tuesday dismissed concerns over a protracted trade war with China, despite a warning by Beijing of financial market chaos.

Grains markets shrugged off the optimistic view and remained focused on Midwest weather. Corn and soybeans are heading into key production phases when stressful conditions can hurt yield prospects.

Below-average condition ratings for both crops have not deviated much in recent weeks, although concerns about dryness have steadily grown.

"We got a little bit more rain than we were expecting last night so that's adding some pressure," said Ted Seifried, chief ag market strategist with Zaner Group.

More rain is expected in the 11- to 15-day forecast, with near-normal temperatures over the next two weeks, according to the Commodity Weather Group.

The US Department of Agriculture pegged 57% of US corn crop in good-to-excellent condition, down 1 percentage point from a week earlier, while soybean conditions were unchanged at 54%. Conditions for both are below average following an overly wet spring planting season.

Chicago Board of Trade September corn fell 1-1/4 cents to $4.04 per bushel. The contract held chart support at its 200-day moving average.

CBOT November soybeans shed 3 cents to settle at $8.65-3/4 a bushel.

CBOT September wheat dropped 10-1/2 cents to $4.84 a bushel as the dollar strengthened. The contract failed to breach technical resistance at its 20-day moving average and selling accelerated as it fell below its 100-day moving average.

"The dollar is giving wheat its cue today. A stronger dollar means weaker wheat," said Mike Zuzolo, president of Global Commodity Analytics.

Abundant global supplies of wheat remained an obstacle for US export sales prospects. A firmer dollar can make US wheat even less attractive to buyers holding other currencies.

No US wheat was offered in a tender by Egypt's state grain buyer. Russian, Ukrainian and Romanian wheat was purchased.