Chicago soybeans and corn rose on Tuesday, remaining near 6-1/2 year highs hit on Monday, as concerns about South American crops and disruptions to exports supported prices.

Wheat rose as the weaker dollar supported grains and soybeans, making U.S. exports more attractive in export markets.

Chicago Board of Trade most-active soybeans rose 1.2% to $13.30 a bushel at 1223 GMT. Soybeans on Monday hit $13.49-1/2 a bushel, the highest since June 2014.

Corn rose 0.2% to $4.85 a bushel, after on Monday hitting $4.97-3/4, also a 6-1/2 year high. Wheat rose 1.1% to $6.49-1/4 a bushel.

Brazil’s soybean harvest started slowly in some areas in top producer Mato Grosso state. Local farmers say harvesting is behind last year’s pace due to scarce rainfall earlier in the season.

“Soybeans are supported again by concern about the Brazilian crop being reduced by recent dry weather,” said Matt Ammermann, StoneX commodity risk manager.

Some Brazilian crop estimates are being reduced but there is concern in the market that larger cuts in forecasts of Brazil’s soybean crop could be on the way.”

Argentina will suspend sales of corn for export until Feb. 28 as the government seeks to ensure ample domestic food supplies.

“Corn is seeing support from concern about dryness in Argentina and the ban on Argentine corn exports,” Ammermann said. “Argentina has had some rain but the debate is whether this is enough as some areas are looking dry.”

“Wheat is being supported by the dollar’s weakness which is positive for U.S. exports as Russia’s export tax approaches in February.”

“Export limitations on Argentine wheat are feared if adverse weather persists given their actions with corn last week. The question is also when will Russia return to export markets, but in the meantime U.S. wheat export prospects are looking positive.”