For most investors, the increasing chance of a deal to settle the US Budget is good news.
The White House and Republican politicians have started talks, which both sides have termed constructive, on ways to approve a short-term extension of the US $16.7tn debt limit.
Shares, which soared 2.2% on Wall Street in the last session, ended up 1.5% in Tokyo on Friday, while adding 1.2% in Hong Kong and 1.7% in Shanghai
For corn investors, however, the return of the government to work comes with a caveat - that it looks like speeding moves to lower the US requirement for blending corn-based ethanol into gasoline.
For bulls on the grain, the US government has not been closed enough in its partial shutdown of the last 10 days or so, with the Environmental Protection Agency using the time to cook up plans to cut the requirement for corn-based ethanol to some 13bn gallons next year.
While investors Agrimoney.com has spoken too had expected a figure below the 14.4bn bushels currently proposed, they had not forecast a number so far beneath this year's 13.8bn bushels.
The move "would lower demand for US corn from the ethanol sector by 500m bushels", compared with the current 2014 target, Joyce Liu at Phillip Futures said.
'Favourable harvest conditions'
While the proposed changes still apparently need to be reviewed by the Office of Management and Budget, fears of a deep cut to ethanol consumption of corn, at a time when US farmers are reaping a record harvest, extended the downward pressure on prices.
Indeed, if many hedge funds last week closed some of their record net shorts in corn futures and options, over concerns at the lack of transparency in markets denied US Department of Agriculture data by the government shutdown, there was considerably less reason now to fear any positive market surprise.
Especially when weather is allowing rapid US harvest progress, and yield reports are still coming in strong.
"Look for favourable harvest conditions in the US to continue into the weekend with mostly dry conditions and mild temperatures," CHS Hedging said.
"Indications continue to show better-than-expected yields for both corn and soybeans."
As to exactly that US crop prospects are, the market is, if course, being denied today the USDA's key monthly Wasde report for the first time in 40 years, thanks to the government shutdown.
However, "there is a mounting risk that the USDA is grossly underestimating 2013 US corn production given ongoing flow of better-than-expected yields", Richard Feltes at RJ O'Brien said.
Informa Economics attempted to fill the gap by releasing outside its usual subscriber base its own proxy Wasde, giving "likely production changes that report would have contained", including an estimate for US corn stocks at the close of 2013-14 of 1.929bn bushels, up from the current USDA forecast of 1.855bn bushels.
For soybeans, end-season stocks were pegged at 180m bushels, up 30m bushels from the estimate in the September Wasde.
For wheat, Informa pegged the world harvest at 709.6m tonnes, up 600,000 tonnes on the September Wasde figure, and reflecting stronger ideas for Australian and Canadian harvests, offset by downgrades to Kazakh and Argentine crops.
(If you have any trouble getting hold of the Informa report, e-mail Agrimoney.com at inquiries@Agrimoney.com.)
'Who needs the USDA?'
Macqaurie, in a report entitled "who needs the USDA?", also came in with some strong ideas on the corn yield, upgrading its forecast to 158.1 bushels per acre, and echoing Lanworth earlier this week in seeing yields above 170 bushels per acre in Illinois, Indiana and Ohio.
Not that all farmers agree. Dawn Peterson, responding to Agrimoney.com's coverage of Lanworth estimates by saying that the consultancy's finding of some strong yields in Illinois "doesn't mean the whole state is like that.
"Northern Illinois is nowhere near those yields," she said.
Furthermore, US cash markets are being supported by a reluctance by growers to sell at low prices.
Still corn for December notched up a fresh three-year low, for a spot contract, of $4.33 a bushel, in early deals before recovering a little ground to stand at $4.33 ½ a bushel as of 09:40 UK time (03:40 Chicago time) down 1.0% on the day.
That was hardly encouraging for wheat, which declined too, although less so, by 0.3% to $6.83 ¾ a bushel in Chicago for December, allowing its premium over corn to get to nigh on $2.50 a bushel.
In fact, there are concerns over the extent of the premium encouraging a wholesale switch in feed demand to corn – which is what markets really should be doing given the contrast between relatively tight wheat supplies and the bumper US corn harvest.
Still, with hopes for Australia's harvest back on the upswing, as Informa noted (above), and talk that India may lower the floor price for its wheat exports, potentially increasing competition on international markets – Egypt cancelling its tender on Thursday because of "high prices" - wheat had its own pressures too.
Indeed, wheat futures "have been overbought", said Brian Henry at Benson Quinn Commodities, adding that "price action in the wheat market looks corrective and likely to continue in the absence of fresh supportive input".
'Whopper of an export sales number'
Of course, such support could yet come from the return of the government to work and a flurry of data showing huge US wheat exports in the last 10 days, with plenty of talk that Brazil is still in the market.
But this is seen as a particularly likely outcome in soybeans.
"There is lots of talk of China picking up one or two cargoes a day off the Gulf and Pacific North West over the past two weeks with crush margins reportedly best in years on a to-arrive basis in China," Benson Quinn Commodities said.
"Some today were already anticipating that USDA, when the government gets back to work, will come out with a whopper of an export sales number that could trigger new fund buying on an increasing demand outlook."
Soybean crush margins in China were reported earlier this week by Morgan Stanley as returning above 100 remninbi per tonne of the oilseed, a marked recovery from the negative margins of 80 remninbi per tonne reached in June.
Still, with pressure on prices from a US harvest in full swing, soybeans for November eased 0.5% to $12.82 ¼ a bushel.
Among soft commodities, raw sugar continued to gain support from the Unica data on Thursday highlighting rain delays to the cane harvest, and sugar production, in Brazil's Centre South.
New York sugar for March added 0.3% to 18.78 cents a pound, setting a near-seven-month high for a spot contract.
Cotton for December added 0.6% to 83.63 cents a pound despite an International Cotton Advisory Committee upgrade to 20.3m tonnes in its forecast for world stocks at the close of 2013-14, and bearish comments from Informa on the US balance sheet too.
Informa pegged the US crop at 13.7m bales, and end-2013-14 domestic stocks at 3.71m bales, both figures up 810,000 bales from the USDA's current estimates.
As an industrial commodity, cotton is more sensitive than food commodities to macro factors, such as the US budget impasse.
Another non-food agricultural commodity, rubber, rose more than 3% in Tokyo to hit 267.00 yen a kilogramme at one stage.