US wheat futures rose on Tuesday, supported by concerns about the US crop following drought in the growing region and a temporary ban on grain shipments by top exporter Russia to former Soviet countries.
Corn and soybeans fell on fears that demand from top consumer China could moderate because of rising Covid-19 cases.
The most-active wheat contract on the Chicago Board of Trade (CBOT) rose 1.4% to $10.85 a bushel, as of 0401 GMT, after falling 15% in the last four sessions.
Russia on Monday temporarily banned grain exports to ex-Soviet countries and most sugar exports, but a senior minister said it would keep on providing special export licences to traders within its current quota.
A worsening drought in the southern US Plains is threatening the region's winter wheat crop just as the Ukraine crisis dents global supplies.
Corn dropped 0.77% to $7.42-1/2 a bushel and soybeans fell 0.87% to $16.56 a bushel.
Near-term feed demand could moderate in China as coronavirus cases are rising at an alarming pace and this could force Beijing to impose more restrictions, said a New Delhi-based trader with a global trading firm.
China reported a steep jump in daily Covid-19 infections on Tuesday, with new cases more than doubling from a day earlier to a two-year high as a virus outbreak expanded rapidly in the country's northeast.
Soybeans have also come under pressure as a drop in palm oil and soyoil prices has reduced the crush margins sharply in a week, the trader said.
Malaysian palm oil futures fell 3% on Tuesday, extending losses to a fourth session.
The market is closely monitoring progress in Russia-Ukraine peace talks, traders said.
Ukraine's President Volodymyr Zelenskiy said late on Monday that negotiations with Russia were to continue on Tuesday.
Oil prices slid to a two-week low on continued ceasefire talks between Russia and Ukraine and concerns about demand in China after a surge in Covid-19 cases.
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