U.S. soybean futures fell on Tuesday to a more than one-year low, weighed down by favourable crop conditions and weather that point to a bumper harvest.
Corn prices were mixed and U.S. wheat rebounded modestly after the previous day's one-year low.
"For summer crops right now, the path of least resistance is lower because there's just not a legitimate weather threat out there now," said Shawn McCambridge, an analyst at Jefferies Bache in Chicago.
Chicago Board of Trade August soybeans, in delivery mode, dipped 0.4 per cent, or 5-1/2 cents, to $13.24-1/4 per bushel, touching the lowest nearby price since June 2012. New-crop November soybeans fell 1.4 per cent, or 16 cents, to $11.67-1/4 a bushel (all figures US$).
"The trade is (seeing) a large increase in production this year and the stocks year over year, and I think it's still weighing on the market," said Bill Nelson, an analyst at Doane Advisory Services.
Weakness in U.S. stocks and in crude oil, tied to soybeans and corn through biofuels markets, hung over the crops.
Nelson said the U.S. Environmental Protection Agency's (EPA) statement that it would use its authority to lower the volume goal for biofuel use in 2014 added to the negative tone around soybeans. Soybean oil is used to make biodiesel.
Condition ratings for U.S. corn and soybeans edged higher in the latest week, spurred by improving crop health in Illinois, U.S. Department of Agriculture data showed on Monday after U.S. markets had closed.
The USDA said good-to-excellent ratings, the highest ranking, for both corn and soybeans rose one percentage point to 64 per cent as of Aug. 4, slightly beating market forecasts.
Chicago September corn rose 0.6 per cent, or three cents, to $4.72-1/4 per bushel, bouncing modestly after matching the previous day's lowest nearby price since October 2010, supported by tight old-crop stocks. Archer Daniels Midland, one of the world's top agricultural trading houses, on Tuesday warned a delayed U.S. corn harvest will keep crop supplies tight.
New-crop December corn slid 0.3 per cent, or 1-1/4 cents, to $4.59-1/4 a bushel.
McCambridge said there was some support for grains from short-covering "but they're not going to get too ambitious because the fundamentals are still bearish."
Investment bank Goldman Sachs Group boosted its forecast of the U.S. corn crop on Tuesday due to good crop weather, and lowered its price forecast for CBOT corn to $4.25 per bushel from its previous forecast of $4.75.
Corn in west-central Iowa, the top U.S. corn state, was on track for big yields but needs rain to ensure that grain kernels fill out to their full potential, surveyors on an annual crop tour reported on Tuesday.
CBOT September wheat gained 0.8 per cent, or 5-1/4 cents, to $6.50-1/2 a bushel after slumping to a low of $6.41-1/2 on Monday, the weakest level for a nearby contract since June 2012.
Egypt's main wheat-buying agency, the General Authority for Supply Commodities, bypassed U.S. supplies and instead bought 120,000 tonnes of Romanian and Ukrainian wheat for shipment Sept. 21-30.
-- Rod Nickel is a Reuters correspondent based in Winnipeg. Additional reporting for Reuters by Nigel Hunt in London and Naveen Thukral in Singapore.