Asian stocks slipped as investors fretted about a broadening global economic slowdown, with sentiment not helped by the absence of any positive signs for a resolution in the US-China trade row.
The most-active soybean contract on the Chicago Board Of Trade was down nearly 0.5 percent for the week, while corn futures were little changed after two consecutive weekly declines.
Wheat was down about 2 percent for the week, its first weekly fall in three.
Soybeans were under pressure as US President Donald Trump and China's Xi Jinping are unlikely to meet, dashing hopes that the two sides were progressing on a deal to end a bitter trade fight.
"There is not much positive news on US-China trade negotiations as Trump said that he will not be meeting his Chinese counterpart before the deadline," said Phin Ziebell, an agribusiness economist with the National Australia Bank.
"Looks like talks aren't going anywhere at this stage."
Market participants were waiting for a long list of US Department of Agriculture crop forecasts and estimates due on Friday after key reports were delayed due to the 35-day partial government shutdown.
The soy harvest in Brazil's second-largest producing state of Parana is well ahead of last season, with limited damage to the fields from drought, state agricultural research body Deral said on Tuesday.
France exported 1.4 million tonnes of soft wheat in December, including 882,000 tonnes shipped outside the European Union, customs data showed on Thursday.