CHICAGO: Chicago Board of Trade corn futures extended a rally early on Thursday above eight-year highs as dry weather threatened harvest yields in major exporter Brazil and kept the focus on ebbing global supplies.

Soybeans approached an 8-1/2-year peak reached last week, buoyed by rallying vegetable oil prices, while wheat was little changed.

Corn crop losses due to dryness in Brazil could shift export demand to the United States, which is already grappling with tight inventories, analysts said.

“We’re still very dry in Brazil,” said Brian Hoops, president of US brokerage Midwest Market Solutions. “That crop is in retreat.”

The most-active corn contract was up 5-1/4 cents at $7.13-3/4 a bushel by 11:25 a.m. CDT (1625 GMT). It earlier touched the highest price since March 2013 at $7.22-1/2. December corn that represents the next US harvest was up 15-1/4 cents at $6.20 a bushel, after setting a contract high of $6.22-1/4.

CBOT wheat was flat at $7.44-1/2 a bushel.

The most-active soyabean contract soared 24-1/2 cents to $15.66-3/4 a bushel. November soyabeans that represent the next harvest set a contract high and were up 26-1/4 cents at $14.09.

Rising new-crop soya and corn prices reflected the battle to incite US farmers to increase plantings to replenish tight stocks, analysts said.

Brokers are beginning to grow nervous that cool weather will slow the emergence of recently planted corn. “There’s some concerns that this year’s crop is not off to one of the greatest starts ever,” Hoops said.

A 13-year high for palm oil, against a backdrop of tight global edible oil supplies, helped boost soyabean futures, traders said.