Soybeans returned to the front foot, helped by evidence that rain had stabilised, rather than improved the US crop as many investors had expected, which fuelled a somewhat Turnaround Tuesday feel.
The US Department of Agriculture in weekly crop data overnight rated the domestic soybean crop at 50% in "good" or "excellent" condition – the same as the week before.
Investors had expected an improvement of 1-2%, but declines in crops in some western and southern growing states offset improvements in the eastern Corn Belt.
That put the brakes on ideas that Midwest rains have done a substantial job in repairing yields, although the real measure, of course, will be what farmers take in the combine.
Still, with the harvest only 3% complete, little can be drawn from yield findings so far, and with contrasting chatter anyway on what growers have found.
Many are talking of forecast-beating results, with one broker noting that the "latest soybean yield reports have been better than expected which may be weighing on prices along with the typical harvest pressure we see at this time of year".
But US Commodities said that "yields on soybeans are variable thus far" - if in a range of 30-60 bushels per acre. The USDA's estimate for the national average is 41.4 bushels per acre.
The data played to an idea that, technically, the selling on soybeans had gone far enough for now, after the fall of some $0.90 a bushel in Chicago's benchmark November contract in less than two weeks.
"The market is technically oversold heading into Tuesday," Benson Quinn Commodities said.
And, after all, demand has been decent, with weekly US exports last week hitting 16.8m bushels, well ahead of expectations, if still below the average of 27.3m bushels that it needs to hit to reach the USDA's forecast for US soybean exports of 1.37bn bushels in 2013-14.
Export levels should be supported by the increase in crop volumes as harvest proceeds.
Still, there was still some bearish talk around, with one broker reminding that "funds have a massive long soybean, short corn position which could lead to large price swings if they decide to unwind that spread in the near future".
At RJ O'Brien, Richard Feltes flagged ideas of "slowing Chinese interest in US soybeans", as state auctions releases supplies within the top importing country, although other observers, such as Standard Chartered, have higher hopes on this score.
And Mr Feltes also highlighted talk that farmers will prove far more willing to sell soybeans, which are at a relatively high price, at harvest rather than meet cashflow needs from selling corn, which is at a far lower price by historical standards.
Furthermore, the macroeconomic backdrop was negative too, with not all investors agreeing with Morgan Stanley that the Federal Reserve's decision to delay tapering of emergency economic support will prove more than a short-term support, and with attention turning to the prospect of another US budget deadlock too.
Nonetheless, soybeans for November added 0.9% to stand at $13.19 ¼ a bushel at 09:00 UK time (03:00 Chicago time).
'Fast pace of exports'
That was enough to outpace wheat, which has been something of a surprise performer of late, standing firm even as corn and soybeans have declined.
Demand for US wheat has been strong, as evidenced in US weekly exports of 42.3m bushels.
"US wheat inspections were very good, and continue to trend much better than year ago levels," up 36% in fact, CHS Hedging said.
Brian Henry, at Benson Quinn Commodities, said: "Soft red winter wheat to China and hard red winter wheat to Brazil and Nigeria remain the features on the fast pace of US wheat exports, while Mexico quietly purchased a large amount of US wheat in the first quarter.
"The fact that they did so while US corn supplies were lacking is a valid indication of how much wheat was fed during the first quarter," a factor "to keep in mind prior to the September 1 quarterly stocks data being released next Monday".
Quarterly stocks reports are a market highlight, giving an insight into crop demand which, for grains especially, more than soybeans, is not completely evident from other USDA and industry data.
Also supporting wheat have been some demand concerns, with the likes of Russia receiving too much rain in the late harvest, and Argentina and, to some extent Australia, too dry.
Australia has received some rains, which have eased concerns something, and prompted a slump in prices from Aus$297.00 a tonne on September 3 to an intraday low of Aus$262.00 a tonne on September 17 in Sydney, for east coast wheat for January delivery.
Still, rainfall has not been universal, and values have recovered since to close at Aus$269.00 a tonne on Tuesday.
In Chicago, December wheat was 0.3% higher at $6.55 ¾ a bushel.
That was just enough to keep the grain's newly-rediscovered $2-a-bushel premium to corn, which for December delivery added 0.6% to $4.55 ¾ a bushel.
Corn has been finding some support in the extent of this premium, getting towards levels which have triggered downwards corrections in the past, and in ideas that investors may indeed unwind long soybean-short corn spreads en masse.
The overnight USDA crop progress data, while showing an expected, if counter-seasonal, improvement in the domestic corn crop condition, by two points to 55% good or excellent, also showed the US harvest proceeding far more slowly than investors had expected.
Just 7% was complete as of Sunday, less than half the average rate, and well below market expectations of a figure of at least 10%, with a slower harvest meaning less harvest pressure on prices.
Soft commodities got off to a broadly positive start too, with arabica coffee building on its gains of the last session and adding 0.5% to 117.60 cents a pound in New York for December delivery.
"The harvesting of Brazil's bumper crop was threatened by rains in the top grower of coffee," Joyce Liu at Phillip Futures said.
And cotton added 0.6% to 84.77 cents a pound, despite the USDA crop progress data showing some improvement in the condition of the US crop, by one point to 44% "good" or "excellent".
"The improvement in both Chinese and European [economic data] is encouraging for final apparel demand," Luke Mathews at Commonwealth Bank of Australia said.
Raw sugar gained 0.3% to 17.30 cents a pound in New York for October delivery, ahead of data from cane industry group Unica later expected to highlight rain delays to the Brazilian Centre South cane harvest.