Chicago | Reuters — U.S. soybean futures fell more than three per cent on Thursday as a plunge in the value of Brazil’s currency encouraged Brazilian farmers to step up sales from their record-large harvest, analysts said.

Corn and wheat followed soybeans lower.

Chicago Board of Trade July soybean futures settled down 31 cents at $9.44-3/4 per bushel after dipping to $9.42-3/4, the contract’s lowest since April 11. The 3.2 per cent slide was the biggest daily drop for a most-active soy contract since Aug. 1.

CBOT July corn ended down 5-1/2 cents at $3.66 a bushel, and July wheat fell 1-1/4 cents at $4.25-3/4 a bushel (all figures US$).

Soybeans sank as the Brazilian real tumbled more than seven per cent following corruption allegations against Brazilian President Michel Temer.

Soybeans are priced in dollars, and because Brazilian farmers are paid in the domestic currency, a weaker real means farmers earn more money for their crop.

Brazil just completed the harvest of its largest-ever soy harvest, estimated by the U.S. Department of Agriculture at 111.6 million tonnes. But farmers had sold only about half of it by early May, compared with the five-year average of 65 per cent.

“The big story in Brazil was, when would they sell? Now, with this much of a drop, this will incentivize Brazilian farmers to sell soybeans,” said consultant Michael Cordonnier, president of Soybean and Corn Advisor.

The slide in CBOT soybeans pressured corn futures. But concerns about too much moisture in portions of the U.S. Corn Belt lent underlying support.

“The corn market has a little bit of its own story with weather forecasts suggesting excessive water in recently planted fields. Will they have to plant again? Will it be too late, and will they have to shift to beans?” asked Tom Fritz, a partner with EFG Group, a brokerage in Chicago.

Tempering wheat futures’ fall was support from larger-than-expected weekly U.S. export sales and news from Wednesday that Egypt’s state grain buyer purchased two cargoes of U.S. wheat at its latest tender.

USDA reported export sales of U.S. wheat in the latest reporting week at 640,600 tonnes (old and new marketing years combined), topping a range of trade expectations.

— Julie Ingwersen is a Reuters correspondent covering grain markets from Chicago. Additional reporting for Reuters by Gus Trompiz in Paris and Naveen Thukral in Singapore.