Sugar and wheat found something in common on Thursday – gains of more than 4%.

For sugar, the surge was attributed to persistent concerns about Brazil's supplies, which look set, thanks to dry weather, to tail-off more quickly than had been thought towards the close of the main crushing season in a couple of months.

And then what? Sure, India looks set to have some to spare for the apparent plethora of buyers.

(Note that Thailand, the second biggest sugar exporter, was reported as selling raw sugar for the Japanese market at a record premium of 900 points over New York prices.)

But, as Nick Penney at Sucden Financial said, "worries persist about a hole in supply at the end of the year and until the Brazil 2011 crush begins".

'Take the medicine'

While the sweetener is technically overbought on some measures, investors seem "happy… to add to longs on any decent dip".

"The shorts expecting weakness have had to take their medicine and cover. We would not advocate bucking the trend," Mr Penney added.

New York raw sugar for October ended a whacking 4.9% higher at 22.43 cents a pound, its best finish since early March, easily eclipsing white sugar, which gained 1.5% to $617.70 a tonne in London.

Big sale 

It was also just enough to beat wheat, despite a sprint finish back above $7 a bushel for Chicago's September lot, after an overnight stay below.

A clutch of drivers were credited for the surge, not least that the sell-off in the last session looked overdone.

But one common cause mentioned was the US Department of Agriculture's announcement through its daily reporting system of the sale of 220,000 tonnes of wheat to an unknown buyer, taking the total in two days nearly to 330,000 tonnes.

"Wheat was up slightly when that occurred and at midday was up 19 cents a bushel as a result of that announcement," Darrell Holaday at Country Futures said, terming the deal the "highlight of the morning".

December wheat actually finished 27 cents, or 3.8%, higher at $7.38 a bushel, with the September contract adding 28 cents, or 4.1%, to $7.06 ¾ a bushel.

Frost and rain 

There was also the technical fillip of 20-day moving averages holding, while a firm performance in Europe surprised some investors, given Chicago's poor close to the last session.

Paris wheat ended up 0.4% higher at E227.75 a tonne for November delivery, with its London peer adding 0.5% to £159.00 a tonne.

Furthermore, Canada is poised for cold temperatures at the weekend, according to Enviro Canada, boding ill for a crop which remains mostly harvested, and indeed about one week behind normal in maturity.

All this kept bearish news at bay, of which there was a bit around, what with the Buenos Aires Grains Exchange edging up its forecast for Argentina's wheat sowings to 4.27m hectares from 4.3m hectares.

Meanwhile "welcome rains last weekend brought relief" to dry crops, "making fertilizing possible", the exchange added.

Furthermore, the former Soviet Union "has seen improving weather", US Commodities noted, adding that "about one-third of the winter wheat belt remains dry, but improving".

Too hot

Corn felt a bit of spillover support from wheat too, and was further helped by thoughts of a downgrade to US crop hopes in the USDA's key crop report on Friday.

"Actual yield results remain disappointing as we move north" on the US harvest, US Commodities noted.

Indeed, "the late corn may not improve as much as needed due to the heat and humidity late in the season", the broker said, noting that the crop "remains the cheapest feed grain in the world".

Corn did a bit to question that record by adding 2.0% to $4.56 ¼ a bushel for September delivery, a fresh 23-month high. The better traded December lot added 1.7% to $4.70 ¾ a bushel.

Funds were buyers of an estimated 15,000 lots.

Chinese clampdown? 

No so soybeans, where funds sold 2,000 contracts, set back by an investigation into commodities trading in China.

While the inquiry was into rubber deals, it was enough to unsettle investors, with China the top buyers of the oilseed.

"[It] sparked fear of a wider crackdown on other Chinese commodity markets," US Commodities said.

Furthermore, soybean yields are holding up better than corn's so far from the early harvest. That said, as many dealers have noted, soybeans' is a demand story at the moment, with traders guessing just how think stocks will be pegged at in Friday's USDA report.

September soybeans ended down 0.3% at $10.37 ¾ a bushel in Chicago, with the November lot easing 0.3% to $10.46 a bushel.