There was blood on the floor in Chicago. But who was to blame?
"We have had a lot of liquidation days in the grains in the last two weeks, but this one will go down as the harshest," Darrell Holaday at Country Futures said.
And that was a fair summation of a day which saw wheat tumble to its lowest price since July last year in Chicago, and stand 8% lower in Paris too at one point.
Chicago corn closed down the daily exchange maximum.
"I know harvest is round the corner. But this was some sell-off," Jerry Gidel at North America Risk Management Services told Agrimoney.com.
The absence of China, and appearance of Russia, appeared to have a lot to do with it.
That is, talk faced of Chinese buyers having [already] bought US corn on the break. And certainly, no sale confirmation emerged through the US Department of Agriculture's daily reporting system.
However, what did appear was news that Tunisia had bought 75,000 tonnes of wheat at around $290 a tonne, freight included, believed from Black Sea exporters, but whatever some $15 a tonne cheaper than French wheat is going for.
"A sale to Tunisia at very aggressive levels suggests Russian or Ukrainian origin, which has depressed EU prices," the UK grain arm of a big European trading house said.
Most of the money was on Russia, whose return to grain trading had been taken with some equanimity, given the reluctance of buyers such as Egypt to trust the country with orders again following its export ban. Trust it, at least, until this year's harvest is in the silo.
Paris wheat for November closed down 7.4% at E196.75 a tonne for November delivery, a three-month finishing low for the contract, and having fallen E1 further at one point.
London wheat for the same month slid 5.8% to a two-month closing low of £164.00 a tonne.
That unnerved Chicago too. "What happened in Paris scared us over here," Mr Gidel said.
And this when political opposition to Greece's austerity plans, raised the idea that the country's problems might not be nearing an end (for now) after all.
If investors needed more reasons to sell, concerns over weather are fading - even over the ridge of hot pressure forecast for the US next week.
"The bulk of the Midwest would welcome warmer temperatures. To this point, the demise of the crop due to hot temperatures has been a tough sell," shallow roots or not, Benson Quinn Commodities said.
And for "now rain makes grain", rival broker US Commodities said.
"Weather has improved around the world. The dry areas of the south east US are now getting moisture. The same is true with some of the dry wheat areas. The central Corn Belt is receiving ideal rain"… and so on.
Funds certainly sold in volume, by an estimated 30,000 contracts in corn, 8,000 in wheat and 7.000 in soybeans.
And this despite some better news on the ethanol front, with production pegged at a healthy 901,000 barrels a day, signalling steady use of corn by biofuels plants.
Nonetheless, July corn locked down the exchange limit of $0.30 a bushel in Chicago to finish at $6.77 ½ a bushel.
July wheat ended down 5.3% at 6.38 ¼ a bushel in Chicago, and off 4.2% at $7.70 a bushel in Kansas.
Among soft commodities, the sell-off managed to throw new crop
The July lot maintained its upward swing, adding 4.2% to 161.22 cents a pound.
And it prompted some caution in
"Overall, we are uneasy with fresh longs around present levels and expect the market to weaken," Thomas Kujawa at Sucden Financial said.
Jurgens Bauer at PitGuru said the "break out on the upside seems based purely on technicals", but others cited factors such as disease and hurricane risks in Florida, the top US citrus-producing state.
The July contract ended down 0.3% at 194.20 cents a pound.