CHICAGO: US wheat edged higher on Wednesday as dry conditions kept crop concerns in focus, but corn and soybeans slid in choppy trading the day before the US Thanksgiving holiday.
Trading was light ahead of the break, leaving markets vulnerable to sudden changes earlier in the session.
"In a thin market like this you can push it down a few cents, and then get to some technical or psychological level and I wouldn't be surprised if two hours from now to see it up a few cents," said analyst Bill Nelson of Doane Advisory Services.
Chicago Board of Trade December wheat rose 0.2 percent, or 2 cents, to $8.47 per bushel by 12:06 p.m. CST (1806 GMT), shrugging off comments by Russia's deputy agriculture minister that Russian grain exports could reach 15.5 million tonnes in the current crop season.
Fears about the declining condition of the US winter wheat crop underpinned prices. Dry weather and record-setting high temperatures are maintaining "severe stress" on hard red winter wheat from South Dakota to Texas, the US Department of Agriculture (USDA) said on Wednesday.
"I'm surprised we're not getting more publicity out of the poor wheat conditions," said Jason Roose, vice-president at US Commodities.
The USDA said on Monday its rating of the winter wheat crop fell to 34 percent good-to-excellent, below analysts' expectations, due to persistent dry conditions in the US Plains.
Chicago December corn was down 0.5 percent, or 3-3/4 cents, at $7.39-1/2 a bushel, on course to snap a three-day winning streak.
After recent disappointing weekly corn export data from the USDA, more poor results are expected Friday, as US corn remains too pricey to be competitive, Roose said.
"You have historically very high prices, and I think even the best merchandisers in the country are saying, 'how long can we keep these strong premiums?'"
Firm US cash markets and tight supplies underpinned corn prices, said Rabobank analyst Erin FitzPatrick.
Chicago January soybeans lost 0.4 percent, or 5-1/4 cents, to $14.07-1/2 a bushel, on technical selling and profit-taking.
Traders were also digesting contradictory demand signals from China during the past week.
Private exporters reported the sale of 120,000 tonnes of US soybeans to China for delivery during the 2012/13 marketing year, according to the USDA on Wednesday.
China, the world's top soy importer, is expected to step up purchases from the overseas market with the government halting the sale of state reserves. Just last week, however, China cancelled orders for 600,000 tonnes of US soybeans, sending soybean prices to a five-month low.
The South American weather forecast appeared slightly supportive for soybean and corn prices, with Argentina looking wetter and southern Brazil drier in the longer term, said Dan Cekander, director of grain market analysis for Newedge USA.
The shorter-term outlook for southern Brazil's dry soybean farms is more favorable, with rain expected by the weekend and into next week, weather forecaster Somar said on Wednesday. That would help kick-start germination of the newly seeded crop.
Hamburg-based oilseed analysts Oil World on Tuesday cut their forecasts for 2013 soybean harvests in Argentina and Brazil by a combined 3 million tonnes because unfavorable weather disrupted sowing.