Poor export demand and generally lackluster demand prospects for corn and soybeans sent those grains tumbling after a few days of bounceback gains on the CME Group floor Thursday.

At the close, March corn was 6 1/2 cents lower at $5.94 3/4 per bushel, while January soybeans were 3 1/4 cents lower at $11.28, according to Barchart.com. March wheat was the lone grain in the black Thursday, ending up 6 1/4 cents higher at $6.02 per bushel.

• From the Wire: Corn and soybeans driven lower on mounting concerns about slower export demand
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Thursday morning's weekly grain export sales numbers came in lower than anticipated for corn, and that stoked fears that previously though tight corn carryout stocks may stretch further than market-watchers thought earlier this spring. On top of demand concerns like that, some traders entered into profit-taking mode toward the end of Thursday's session, contributing to the lower close.

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