U.S. soybeans eased for a 10th straight session on Monday to touch a new two-month low as the spread of a coronavirus continued to cause concern about an economic hit to China, including in oilseed demand.
Chicago wheat was down for a seventh consecutive session on Monday after hitting a near four-week low, with a stronger dollar adding pressure as it dented U.S. export prospects.
Corn also ticked lower but remained underpinned by a run of recent export sales.
The most active Chicago Board of Trade soybean contract was down 0.1% at $8.72 a bushel by 1324 GMT, after falling earlier to $8.68-3/4, its weakest since 3 December.
The death toll from the new coronavirus in China surpassed 350 on Sunday, and Chinese share and commodity markets tumbled on Monday as trading resumed after an extended Lunar New Year break.
China's central bank unexpectedly lowered the interest rates on reverse repurchase agreements by 10 basis points, as authorities stepped up measures to relieve pressure on the economy from the virus outbreak.
The health emergency in China has added to uncertainty about import demand in China, the world's largest soybean buyer.
A swine fever epidemic has already reduced soybean use for pig feed and a lack of major Chinese purchases since a trade deal last month between Beijing and Washington has also dampened demand sentiment.
"This week, markets will continue to watch the severity of the Coronavirus and any signs of Chinese purchases with the Lunar New Year holiday over," brokerage Allendale said in a note.
A firm dollar, which rose against a basket of other currencies, also curbed export sentiment on the U.S. market.
CBOT corn lost 0.3% to $3.80 a bushel, while wheat eased 0.6% to $5.50-1/4 a bushel, after dropping earlier to its lowest since Jan. 8 at $5.46-1/2.
"The stronger greenback is challenging for wheat prices," said Tobin Gorey, director of agricultural strategy, Commonwealth Bank of Australia.
Chicago wheat has been retreating from a 1-1/2 year high struck on 22 January, curbed by the potential for a large Russian harvest this year and stiff export competition from suppliers in the Black Sea region and Europe.
Overseas demand for U.S. corn has been more promising at a time of tight availability in South America.
The U.S. Agriculture Department said on Friday morning that private exporters reported the sale of 134,000 tonnes of corn for delivery to South Korea in the 2019/20 marketing year.