Wheat's close limit up in Chicago's last session implied that some buying pressure had gone unfulfilled.

And this was released in early deals on Friday with gusto.

Indeed, Chicago's September lot came within 5 cents a bushel of going limit up again at one point, before retreating a touch to $8.33 a bushel as of 06:45 GMT (07:45 UK time), up 6.0% on the day.

The rise also took the contract's gains to the week above 25%. Near-term Chicago wheat has now rebounded 88% from a low at the end of June.

'Bullish development'

Russia's grain export ban was cited as the reason behind the rise, removing the world's third biggest wheat exporting country in 2009-10 from shipments, and potentially taking Kazakhstan with it, is a request from Moscow goes fulfilled.

"Yes, there could be a quick sell off coming" on profit-taking, Mike Mawdsley at Market 1 said. "But longer term it is a bullish development."

The curbs have caused shockwaves around the world, sparking fears for food prices, let alone for jumps in other crops, and have not been universally popular even at home, despite preserving domestic grain supplies after drought damage to this year's crop.

The Russian Grain Union urged the government to postpone the start of the ban to September 1, from August 15, allowing some 650,000 tonnes in ports or on their way there to depart the country.

Still, the extent of the rising demand for wheat within Russia was illustrated by comments from the state's United Grain Company that it was tightening security around its silos.

Chicago vs Kansas 

And in Chicago, the demand for wheat, notably among funds, has sent it soaring through, for instance, the $7.70 a bushel resistance level suggested by Fibonacci pattern chart analysis.

Another one, the so-called 50% retracement level (from the last spike), is set at $8.80 a bushel, according to Mr Mawdsley.

It is indeed Chicago that has actually been the epicentre of recent buying, moreso for instance than Kansas, where December wheat traded at a discount of nearly 30 cents a bushel to its Chicago peer at one stage on Friday.

"Historically, Kansas has not traded much more than at a 20-30 cent [a bushel] discount to the Chicago, but back in August of 2007 it did trade as much as 50 cents under," Dave Lehl at Benson Quinn Commodities noted.

In Australia, by the way, New South Wales wheat for January jumped by 11.3% to Aus$330 a tonne, with the Western Australia lot up 11.4% at Aus$347 a tonne. While the east of the country is on for a bumper harvest, dry weather has raised a big question mark over the crop in Western Australia, the top grain state.

Corn competition

But will the high world wheat prices hold? UK grain merchant Gleadell said that selling into the rally "surely makes sense", noting the huge US wheat stocks, and the relative cheapness of corn.

"Corn is now undercutting wheat on a worldwide basis - in the European Union by upwards of E30 [a tonne]. At this level many feed compounders will switch out of using wheat," Gleadell said.

The discount was only getting bigger in early deals, with corn for September delivery up a modest 0.7% at $4.06 � a bushel in Chicago.

Soybeans, which have less interchangeability with wheat among users, and have trod more of their own path, were 8 cents lower at $10.46 � a bushel for August delivery, and up 2.25 cents at $10.31 � a bushel for November.

Palm high 

In Kuala Lumpur, palm oil added 0.9% to 2,643 ringgit a tonne in morning trade, after hitting 2,648 ringgit a tonne at one point, its best for nearly four months.

The rise was attributed to the broad surge of interest in commodities, and to the potential for stockpiling ahead of festivals such as Ramadan to deplete Malaysia's stocks of the vegetable oil.