Chicago crops continued to decline, with soybeans ending particularly weakly, as the long retreat from the frost-fuelled rally continued, spurred by worsening sentiment in many financial markets.
Oil lost 3%, and gold slipped back below $1,000 an ounce, as investors dug in at the start of a week which will bring a Federal Reserve interest rate decision and a meeting of G20 finance ministers.
Predictably, with investors seeking to reduce their exposure to risk, the dollar recovered ground, hitting a two-week high against the yen and recovering to $1.4647 against the euro.
This made dollar-denominated assets, including crops, more expensive to foreign buyers.
With China reassuring on crop production, despite frost and drought threats which raised question marks in recent weeks, bulls had little in the way of fundamentals to latch on to.
Although New South Wales, Australia's second-biggest wheat producing state, cut its forecast for wheat production by 1m tonnes, it was not clear – either to Agrimoney.com or to London and Sydney analysts – to where, or from where, the cut was made.
Analysts at one Sydney bank contacted by Agrimoney.com said they were going with the official data for now.
The market was left at the mercy of the weather forecasts, which showed little risk of the frost threat which sent prices soaring last week.
Indeed, temperatures may even be warmer than usual this week, some forecasters said, raising the prospect of corn yields and soybean crops breaking records by even greater margins than analysts are currently expecting.
November soybeans closed down 31.0 cents at $9.10 a bushel in Chicago, with forward contracts showing similar declines.
December corn dipped 2.25 cents to $3.15 ¾ a bushel, if closing well above its day low, while December wheat ended 2.5 cents lower at $4.54 ¾ a bushel, treading back nearer two-year lows.
Wheat slipped in Europe too, down E0.75 to E120.50 a tonne in Paris for November delivery.It also fell £0.75 to £96.75 a tonne in London, despite continuing weakness in sterling following comments by the