CHICAGO, Oct 14 (Reuters): US corn and soybean futures fell on Monday on supply pressure after the US government reiterated its bumper crop forecast while improving rains in Brazil eased concerns that a dry start to the planting season would dent its harvest prospects.
Wheat futures declined as the dollar strengthened and after the US Department of Agriculture (USDA) raised its outlook for global wheat supply in a monthly report on Friday.
Corn and soy markets remained anchored by generally favorable harvest weather in the US Midwest and a shift to wetter weather in key South American production areas.
"The government is telling us the yields are bigger, not smaller, for (US) corn. And the soybean yields are not as small as we thought given the weather that we had in August and September," said Don Roose, president of brokerage US Commodities.
"The other theme is that Brazil, our big competitor in corn and soybeans, has a weather pattern change for planting."
Soybean planting in Brazil reached 8.2 per cent of the expected area as of last Thursday, behind last year's 17 per cent, according to consultancy AgRural.
Chicago Board of Trade November soybeans hit a one-month low and ended down 9-1/2 cents at $9.96 a bushel. December corn dropped 7-1/2 cents to $4.08-1/4 a bushel, a three-week low.
The USDA's closely followed weekly crop progress and conditions report is due to be released on Tuesday, delayed by a day due to a federal holiday on Monday.
CBOT December wheat settled 13-3/4 cents lower at $5.85-1/4 a bushel, weighed down by technical selling and despite uncertainty around Black Sea supplies.
Russian authorities set a price floor for exports, which could stem the top supplier's brisk exports.
Meanwhile, another Russian missile attack on Ukraine's Black Sea port of Odesa on Monday underscored war risks to Black Sea trade.