Just what is going on with Argentine wheat?
First, the South American country's farm ministry, late on Thursday, pegs the domestic wheat crop at 8.8m tonnes.
That figure, well below market expectations, sends market prices higher, to a four-month high for a spot lot of $7.11 ¼ a bushel in Chicago, for the December contract.
The fear was not just that Argentine export volumes would suffer, at a time when neighbouring Brazil requires extra import volumes, but halt altogether, with the small harvest and risk of spiralling flour and bread prices prompting the government to ban shipments.
Mistake, or not?
However, the ministry on Monday, ie four days later, said it got the wheat estimate wrong, and that it was only a "partial" figure.
That was on the face of it a negative for values, and indeed Chicago wheat fell back to $6.94 a bushel.
But the contract didn't stay there, recovering some lost ground to close at $6.99 ¼ a bushel down 0.9%.
Was the figure really so wrong?
The ministry's inability to confirm an immediate correction, potentially until next week – after mid-term elections on Sunday – raised ideas that the figure had been withdrawn to cut talk of an export ban, which would be deeply unpopular with farmers, ahead of a poll at which the ruling coalition is expected to lose considerable ground.
It would certainly reduce the threat of a protest by Argentina's farmers, who have a habit of demonstrating, ahead of the elections.
'Weather continues to improve'
The one definite negative for values from Argentina was an improvement in the weather, with rains boosting hopes for a crop which has suffered from a lack of moisture.
"Argentina weather continues to improve in central and southern Argentina. This is helping the wheat and newly-planted corn," US Commodities said.
Furthermore, in the Black Sea weather turned more benign too for sowings, meaning a drier spell.
"Drier conditions in the Black Sea Region are allowing more winter wheat planting and the finish of the fall harvest this week," Darrell Holaday at Kansas-based Country Futures said.
'Seedings are aggressive'
Meanwhile, in the US weather remains strong for winter wheat plantings too.
"The Canadian wheat crop is large and the US winter wheat seedings are aggressive with adequate moisture levels," US Commodities said.
Just how aggressive, investors will find out later with the USDA's first crop progress report of the month, after two weeks missed because of the US government shutdown.
And as for demand, weekly US exports, as measured by cargo inspections, were not so hot either, at 20.6m bushels, down from 27.2m bushels the week before.
In Paris, wheat for November ended higher, but only by the minimum E0.25 to E204.75 a tonne, well below an intraday top of E206.50 a tonne.
For soybeans, signs of export demand were a lot more buoyant, and futures with them.
For a start, the USDA unveiled through its daily alerts system the sale of 235,000 tonnes of the oilseed to "unknown" destinations.
(This following 362,000 tonnes announced on Friday, split between China and "unknown".)
Then, the weekly export data showed a hefty 59.3m bushels of soybeans shipped last week, up from 47.4m bushels the week before, and indicating that new crop supplies are indeed finding buyers.
"Soybean cargo inspections were bullish," CHS Hedging said.
And this against a backdrop of rumours of continued Chinese orders, and of decent demand within the US too.
"Strong domestic and export demand for soybeans and soymeal offers support," Benson Quinn Commodities said.
Sure, "harvest pressure and a little better production estimates offers resistance", but hopes for the US harvest are only getting a little better, with the latest Reuters poll at 41.9 bushels per acre, only up 0.2 bushels per acre from the last.
Soybeans for November closed at $13.03 ¼ a bushel, up 0.9%, and enhancing their technical credentials by ending over $13 a bushel for the first time this month.
Corn had its own positive export news, with weekly US cargo inspections coming in at 32.3m bushels, up 10.0m bushels week on week and three times the level for the same week last year.
And prices have been held up by - besides those of fellow grain wheat, to which corn's discount is unusually large – growing competitiveness against Ukraine supplies, which have been held up by a rain-delayed harvest.
A firm US cash market, a reflection of a reluctance by growers to sell at relatively low prices, has helped too.
But for how long? The Reuters poll shows analysts believe the US corn harvest will come in at 157.2 bushels per acre, up 0.7 bushels per acre from the previous poll.
Corn gains, but it headway was limited to 0.6%, taking the December lot to $4.44 a bushel.
'Feeling the market should fall'
Among soft commodities, the big question was whether raw sugar could keep up the pace, after closing the last session at the highest finish this year for a spot contract, lifted by news of the fire at the Copersucar sugar terminal in the Brazilian port of Santos.
In fact, Copersucar lowered ideas of the amount of sugar destroyed, to 180,000 tonnes from the 300,000 tonnes floating in the market on Friday.
However, "given that a global supply surplus of 4.5 million tons is anticipated, such losses should not pose any serious problem", Commerzbank said.
Indeed, "the real case in point should be how logistics will be affected," Sucden Financial said, flagging initial talk "that the terminal will be a good six months before being fully operational again".
Still, with the relative strength index for sugar, a key momentum indicator, showing that the sweetener has been "overbought, there is more feeling that the market should fall over this week", Sucden said.
And, indeed, raw sugar for March eased 0.4% to 19.42 cents a pound.
Coffee fared worse, falling 2.0% in London to $1,585 a tonne for January delivery, the lowest for a spot contract since September 2010, pressed by expectations for a strong Vietnamese harvest.
Cash prices in Vietnam itself have fallen to three-year lows too, below the equivalent of $1,650 a tonne.
And, robusta's performance dragged on arabica beans, which ended down 1.7% at 112.70 cents a pound in New York for December delivery.
Goldman Sachs and Societe Generale last week issued bearish comments on arabica prices.