An escalation of chatter over some of the concerns that Agrimoney.com has been breaking over the last few days kept farm commodities just ahead on a day when many risk assets had a tougher time.

The prospect on Wednesday of the next round of talks on a eurozone rescue package kept many investors sidelined.

Barclays Capital said: "Expectations for more decisive action emerging from the next summit appear to be growing.

"[But] we remain cautious on the euro and risky assets in the run up to the summit and beyond."

That explained negative closes on many share markets, with Tokyo shares ending 0.9% lower and Sydney stocks shedding 0.6%.

In another sign of a more "risk off" atmosphere, the dollar added 0.2%, a headwind for dollar-denominated exports such as many commodities in making them less affordable to buyers in other currencies.

'Wetter than average'

Still, wheat managed to edge higher, by 0.4% to $6.44 ¾ a bushel in Chicago for December delivery as of 07:50 GMT (08:50 UK time), after the rumours of Chinese purchases of the grain, revealed by Agrimoney.com last week, were taken up by Reuters, which put the purchases at about 500,000 tonnes in the last two weeks.

The grain, for delivery early in 2012, appears to have been of milling grade, so mitigating against the idea of large-scale wheat-for-corn substitution.

Also the forecasts of rain on its way to Australia, which this website reported on Monday, made the mainstream too, after official meteorologists took up the theme to warn of a "wetter than average" summer over much of the country.

The rains are not expected to come near those of last year, when they sent crop quality plunging. But it does speak of harvest delays and ample supplies of feed wheat for another season.

'Rather poor rating'

Also, a US Department of Agriculture report out overnight pegged the condition of drought-tested US hard red winter seedlings at 47% in "good" or "excellent" health, the same as a year ago – but that's not saying much.

"This is a rather poor rating," Luke Mathews at Commonwealth Bank of Australia said.

Two years ago, the figure was above 60%.

Still, much of that has already been factored into prices of hard red winter wheat, which gained 0.2% to $7.36 ¼ a bushel in Kansas for December delivery.

Chinese imports…

Indeed, unlike in the last session, wheat could not keep up with corn, helped by an admission at last from China that it may need hefty imports of corn too.

The CNGOIC crop bureau pegged 2011-12 corn imports at 5m tonnes, well above the 2.0m tonnes that the USDA has forecast, and appearing at odds with some more conservative statements on the country's need for foreign supplies.

(Many external analysts, of course, have for ages been predicting higher figures, with the US Grains Council talking of a figure of 10m tonnes, and FCStone last week saying high prices suggested China's supplies were far smaller than had been suggested.)

Harvest delays

Furthermore, the USDA crop progress data showed US corn harvesting not proceeding quite as effortlessly as many traders had expected, with 65% completed so far thanks to

"Rains in parts of Indiana, Ohio, and Michigan continue to slow the pace in that region of the country," Jon Michalscheck at Benson Quinn Commodities said.

"At face value those three states still show approximately 1.2bn bushels still in the field, or 27.5% of the total to harvest," a proportion he expected to rise in next week's data.

Chicago corn for December added 0.7% to $6.55 ¾ a bushel, re-expanding its premium over Chicago wheat.

Condition dips

And, returning to the China theme, soybeans continued to get a help from Monday's data showing Chinese manufacturing returning to expansion, relaxing fears for the country's economic welfare.

China is the top importer of the oilseed, which rose 0.6% to $12.33 ¾ a bushel in Chicago, for November delivery.

It is the top importer of cotton too, which added 0.1% to 98.08 cents a pound in New York for December delivery, continuing a fragile recovery.

The condition of the US crop also returned to declining, with the proportion rated "good" or "excellent" dropping 1 point to 29%, according to the USDA.

Sugar investors might also like to note a 3.7% jump to 6,772 yuan a tonne in May futures of the sweetener on the Zhengzhou exchange, amid growing expectations of large Chinese purchases.