CHICAGO: US wheat futures firmed on Wednesday, rebounding from a sharp decline a day earlier as investors used the drop to cover short positions, traders said.

Soybean futures weakened to their lowest in more than a month, pressured by a steep fall in the crude oil market. Corn was mixed, with old-crop contracts rising on short covering while forecasts for good weather for pollination during early July pressured the back-month contracts.

“It is all about the weather at this point,” said Greg Grow, director of agribusiness at Archer Financial Services. “We had a weather premium in the market Friday. “The market kind of flipped when the weather forecast started to look more favorable.” Renewed fears about supply shortages after a Russian strike on the Ukrainian port city of Mykolaiv, added support to wheat, which had tumbled nearly 6% to their lowest since late March on Tuesday.

At 11:25 a.m. CDT (1625 GMT), Chicago Board of Trade July soft red winter wheat futures were up 19-3/4 cents at $9.95 a bushel.

The sell-off on Tuesday had stemmed in part from fresh Turkish moves to help negotiate sea passage for Ukrainian grain also eased supply worries.

But news that Russian missiles had hit Mykolaiv on Wednesday, a strike reported by regional governor Vitaliy Kim, cast doubt on prospects for Ukrainian ports being reopened. Bunge said its grain facility in the city was hit during the attack and Viterra confirmed that its port terminal there was on fire.

“Everyone keeps talking about shipping corridors but it doesn’t add up,” a European trader said.

CBOT July corn futures were up 3-1/2 cents at $7.64-1/4 a bushel and CBOT December corn was down 5-1/4 cents at $6.96-1/4.