Benchmark soybean futures rebounded nearly back to $14 a bushel after US officials warned that domestic supplies would rise only marginally in 2013-14 from last season's levels, which were among the tightest in history.
The US Department of Agriculture's monthly Wasde crop report turned out to be a bit of a slow burn affair, in terms of encouraging price rises.
Initially, investors focused on a bearish data point - an unexpected rise of 0.9 bushels per acre to 155.3 bushels per acre in the estimate for the US corn yield, and a surprise uplift to the estimate for end-season stocks, to 1.855bn bushels, too.
While the USDA edged lower, by 1 bushel per acre, its forecast for the corn yield in Iowa, the top producing state where dryness has been particularly marked, it lifted expectations for results in some more southerly states which had more rain.
The Arkansas yield estimate was lifted by 5 bushels per acre, and that in Tennessee by 6 bushels per acre, with the Plains state of Kansas seeing a 9 bushels-per-acre upgrade.
Still, that tallies with harvest results.
US Commodities said: "Thus far yield results continue to be better than expected. Southern yields are consistently large."
'Basis levels falling apart'
There were some other reasons to get bearish on corn too, with the USDA also lifting its estimate for world inventories at the close of 2013-14, a reflection also of downgrades to hopes for corn feeding in Argentina, Canada and Serbia.
Furthermore, separate USDA data on US exports came in below forecasts, at 332,600 tonnes, of which more than half were for Mexico.
Indeed, with US corn export offers not that competitive, "at the current world price situation, the USDA's export number for 2013-14 is very vulnerable to downward revision", Darrell Holaday at Country Futures said.
And the US corn basis is flagging too under the weight of supplies released from the accelerating harvest.
US Commodities said: "Basis levels continue to fall apart as harvest picks up. Corn basis levels were mixed to down $1.00 a bushel across the Corn Belt yesterday."
Soybeans vs corn
Still, Chicago corn for December, which fell more than 3% at one point to $4.56 ¼ a bushel, its lowest for nearly a month, recovered some ground to finish at $4.66 ¼ a bushel, a drop of 1.3%.
The revisions, after all, were really about the size of a US corn supply cushion which will be huge, whatever.
The grain also felt a tug from soybeans, which soared 2.8% to $13.96 a bushel for November delivery, the contract's best close in a year, boosted by the altogether-more-bullish revisions to USDA balance sheets for the oilseed.
At the closing price, the price ratio of November soybeans to December corn was a mammoth 2.99:1, up from 2.17:1 reached early in 2013.
Figures anywhere near 3.0:1 are rarely chartered territory, and many analysts, such as Bill Tierney at AgResource, have highlighted that high ratios are not sustainable for too long.
The bullish boost to soybeans sprung in part from a cut to the yield forecast of 1.4 bushels per acre to 41.2 bushels per acre – bang in line with market expectations (to the surprise of many investors, given that a downgrade of this extent is unusual in a September Wasde).
However, also supporting prices was that the USDA slashed its forecast for US soybean stocks at the close of 2013-14 to 150m bushels, just 25m bushels above the historically low carryout from last season, and below market expectations too.
"The soybean balance sheet continued its steady march to last year's carryout level with the yield reduction," CHS Hedging said.
"In fact, without a cut in use totalling 36m bushels, carryout would have dropped below 125m bushels, instead of the published 150m bushels."
Sure, there were some other negatives for investors to take note of too, including disappointing weekly US export sales, at 478,100 tonnes.
For soybeans too, cash markets are weakening too as harvest begins, with basis "down 10-130 cents a bushel across the grain belt", US Commodities said.
Rains are building in the Midwest, providing some late refreshment to parched crops, if viewed as too late for many.
And the strong soybean prices, compared with corn, look like encouraging huge sowings in Brazil, set to overtake the US in 2013-14 as a producer of the oilseed.
However, all this was trumped by the low US stocks number to give November soybeans their second highest close, for the contract, and only by a small margin too.
Wheat revives too
For wheat, the Wasde took on a less bearish tinge too as investors focused on the details.
While the world production estimate was lifted by 3.0m tonnes to 708.9m tonnes, that was largely down to an upgrade for the Canadian harvest which, as CHS Hedging noted, was "foreshadowed by the Statistics Canada number" earlier this month.
Furthermore, the USDA made no changes were made to southern hemisphere production from Australia, Argentina, or Brazil, in all three of which wheat crops have suffered weather setbacks.
"South American production remains vulnerable due to early season weather adversity," CHS said a little before the close, adding that "the wheat report had a neutral tone, but futures markets are getting pressure from lower corn markets".
Still, wheat recovered by the close to end up 0.8% at $6.53 a bushel in Chicago for December delivery.
The recovery came too late to prevent Paris wheat for November closing down 0.7% at E188.75 a tonne, despite huge weekly European Union export data for this week, of 715,000 tonnes.
Still, Paris wheat felt the weight of two upgrades to the European Union crop on Thursday, from the USDA and Strategie Grains.
Cotton recovers too
Among soft commodities, cotton, also a rival with soybeans for South American sowings, also staged a recovery from early lows prompted by what were deemed bearish Wasde revisions.
The USDA cut its estimate for domestic production, as many investors had expected, by 150,000 bales to 12.9m bales.
But it lifted its forecast for US stocks at the close of 2013-14 all the same, by 100,000 bales to 2.9m bales, thanks to higher carry-in inventories and weaker expectations for inventories.
The world stocks figure was raised too, by 1.0m bales to a record 94.7m bales.
Still, New York cotton for December revived from a lot of 83.56 cents a pound to finish at 84.75 cents a pound, a gain of 0.5%.
And cocoa for December close up 0.7% at $2,591 a tonne in New York, the best finish for the contract in nigh on a year, helped by supportive comments from London-based Marex Spectron.
The broker pegged the world cocoa production deficit 2012-13 at 161,000 tonnes, three times the estimate from the International Cocoa Organization two weeks ago, and forecast the figure for 2013-14, which starts next month at 134,000 tonnes.
The stocks-to-grind ratio, a key pricing metric, will fall to 40% by the end of next season, from 50% at the close of 2011-12, and looks like maintaining its passage downward.
"A rare combination of higher average prices and favourable weather are required to prevent this ratio falling further thereafter," Marex said.
'Uncomfortably low levels'
With level of supply cover among major cocoa users at "uncomfortably low levels", a sell-down by non-commercial investors of their huge net long is needed for consumers "to maintain or extend cover at levels lower than currently available".
Hedge funds have their largest net long in five years in New York cocoa futures and options.