Jitters ahead of US President Barack Obama's State of the Union Address, and the US Federal reserve meeting; a stronger dollar; rain forecast in Argentina; rumours of cancelled Chinese soybean orders.

There were no shortage of reasons to sell crops on Wednesday. And investors weren't too shy to take them, sending all Chicago's big three crops lower, with funds sellers of 3,000 wheat contracts and 5,000 each of corn and soybean lots with an hour or so of trading to go.

A lot of the selling spilled over into crops too, sending cocoa, coffee and sugar down some 3%. (Orange juice, as ever, took a contrarian stance, leaping 2.3% on residual fears for frost damage to Florida groves earlier this month.)

The conclusion of Vic Lespinasse, the GrainAnalyst analyst, that "prices continued their afternoon sell-off, ending at new lows for the day in several pits" applied well beyond Chicago.

Decree nicey or nasty? 

Crops had, in fact, little respite, with concerns about what further anti-bank cards President Obama had up his sleeve for today's speech widely cited as a reason for caution, even before live trading started.

"The president has already threatened to curb prop trading by banks and traders will be watching to see if he provides further directives on this initiative," Benson Quinn Commodities said.

Then there was the prospect of the US Federal Reserve's latest interest rate decision, another reason for uncertainty, and lingering concerns about a Chinese slowdown.

Even if these did not affect crops directly (China did, see below), they did so indirectly by sending the dollar, investors' favoured safe haven, to a six-month high against the euro of nigh on $1.40.

So much for the competitiveness of dollar-denominated exports. Indeed, oil fell below $73 a barrel for the first time in a month, another blow for crops, such as corn, used in making biofuels.

Bearish spirit 

As for China, the world's biggest buyer of soybeans, Darrell Holaday of broker Country Futures said: "Uncertainty in China continues to haunt this market."

And that's not just down to the broader economic picture.

As rival broker US Commodities said: "Rumours continue to swirl that China is cancelling soybeans," adding that with some 7m tonnes of soybeans ordered yet to be shipped "this is possible".

Record breaker

Factor in moisture relief for somewhat parched Argentine crops – "rains are forecasted to start on Friday with a couple of more systems expected to move across the region the following week," Benson Quinn said.

Mr Holaday added: "The very good conditions now have the industry talking about a corn yield in Argentina over 150 bushels per acre.  The previous record was 128 bushels per acre."

The scene was set for a 2.0% drop to $9.29 a bushel in March soybeans, a fresh three-month low.

Interestingly, soymeal did worse, sliding 2.1%, and soyoil somewhat better, slipping 1.2%, which was the kind of trend that Oil World forecast in a report on Tuesday.

London landmark

The grains also set fresh three-month lows, with wheat tumbling 2.1% to $4.83 ¾ a bushel for March delivery.

Beside the huge stocks scenario, there was some concern over a low pace of Russian wheat exports in December which, in inferring a huge overhang of stock left to sell, was given a negative spin by investors.

In relative terms, corn's close down 1.1% at $3.58 ¼ a bushel for March looked modest.

Still, surely with the euro at a six-month low, at least European crops would produce something more positive?

No. Partly in sympathy with Chicago's debacle, and amid some disappointment at losing out on Egypt's latest tender, Paris wheat for March ended down E1.00 at E125.75 a tonne.

London wheat, indeed, had a strengthened pound to deal with. The March contract ended down £1.80 at £98.75 a tonne, its first slide below a ton a tonne since September.