
By Karl Plume
CHICAGO, Feb 27 (Reuters) - U.S. wheat futures rallied to a one-year high on Friday as worries about a U.S.-Iran military conflict sparked short covering by funds that hold large short positions in the market.
Corn scaled a seven-week top, fuelled by technical buying and spillover support from wheat. Soybeans held firm near a 20-month peak as investors weighed likely strong demand from biofuels makers against uncertainty about purchases by top importer China and a likely record harvest in Brazil.
Commodities markets have been unsettled as investors fret about inconclusive talks on Thursday between Washington and Tehran, despite mediator Oman's talk of progress. Other markets are taking cues from crude oil, which rose 2%. O/R
"People remember the Russian-Ukraine invasion when wheat took off to ten dollars. The funds are caught short and I think this is one of those 'seller beware' situations going into a weekend where anything could happen," said Don Roose, president of U.S. Commodities.
Chicago Board of Trade May wheat futures WK26 were up 18-1/4 cents at $5.92-3/4 a bushel at 11:45 a.m. CST (1745 GMT) after touching the highest point for a most-active contract Wv1 since February 2025. Buying accelerated as the contract topped a high posted on Monday.
CBOT May corn was up 5 cents at $4.48-1/2 a bushel after breaking through technical chart resistance at its 100- and 200-day moving averages. May soybeans SK26 rose 3-1/2 cents to $11.67 a bushel, just below a 20-month high posted a day earlier.
Soybeans remained underpinned by recent bullish biofuels news and hopes that China would book more U.S. shipments, although a record harvest in rival supplier Brazil capped gains.
A Reuters report on Thursday, which said the U.S. administration plans to require big oil refineries to make up for at least half of the biofuel blending exemptions, reinforced expectations that upcoming revisions to U.S. biofuel policy will boost demand for feedstocks like soyoil.
But Chinese demand for U.S. soy remained unclear after a Supreme Court ruling against some U.S. tariffs prompted President Donald Trump to introduce other levies.