Not for the first time, agricultural commodities ran into a bit of "buy the rumour, sell the fact" thinking.

The casualty was soybeans, whose run of resilience, even when grains were falling, ran into a pre-weekend selling drive, despite having some strong fundamental news to throw at investors.

Strike in Santos

In Brazil, port workers began their strike, as threatened, halting the loading of the likes of soybeans, sugar and corn onto boats in the main port of Santos, and slowing operations at other docks.

And this when queues of boats waiting to load up, and lorries to unload, were already long.

Santos had 59 boats waiting to load grain as of Thursday, twice as many as a year before, according to SA Commodities/Unimar data.

At Paranagua, the queue was 82, compared with 31 a year ago.

China purchases

So it was not perhaps too surprising that the US Department of Agriculture was able to confirm rumours that China had been in the market for more than the 120,000 tonnes of US soybeans revealed so far this week (and maybe more, with a 130,000-tonne order booked separately to "unknown").

China purchased a further 410,000 tonnes of soybeans, including 60,000 tonnes of 2012-13 crop, the USDA said.

However, the fact proved less supportive to prices than the rumour, which had helped drive prices of Chicago's March contract up to \$15.16 ½ a bushel in early deals, the lot's highest since early December.

Having found \$15 a bushel difficult to break through early in the month, the contract found it tricky to keep hold of on Friday, and stood 1.0% lower at \$14.73 a bushel with half an hour's trading to go.

'Disappointing to the market'

In truth, weekly export sales data released separately, for last week, offered cause for some alarm, in showing net cancellations of 119,500 tonnes of 2012-13 soybeans, the worst old crop reading since July 2011.

It was also more than enough to offset sales of 62,000 for 2013-14 crop.

"That was disappointing to the market and was one of the reasons the market backed up," Darrell Holaday at Country Futures said.

That said, the data did refer to a period when many Asian buyers, including China, were out for lunar new year holidays.

"Keep in mind, most of the recent sales have occurred since last Thursday and will not show up until next week's export sales report," Mr Holaday said.

'Negative numbers'

Furthermore, the USDA, at its Outlook forum, forecast a healthy rebound in US soybean stocks in 2013-14, to 250m bushels (6.8m tonnes), which would be a seven-year high.

The forecast reflected the idea of a record, 4.55bn-bushel harvest, as outlined on Thursday, but with the domestic crush not recovering to 2011-12 levels, from volumes this season affected by the impact of drought-hit harvest in shortening supplies.

"The numbers released continue to be negative," broker US Commodities said.

'Sell the rumour…?'

The USDA forecasts were downbeat for corn too, in showing stocks more than tripling, nearly to 2.1bn bushels in 2013-14.

And that figure could prove even greater if the International Grains Council proves correct, and sowings come in nearer 99m acres than the 86.5m acres the USDA is forecasting.

Still, if there was hope, for bulls, it was from a little "sell the rumour, buy the fact" thinking.

After all, "the negative numbers have been anticipated for a number weeks", as US Commodities said.

"Last year the USDA projected similar negative numbers," only to see drought shatter crop hopes.

'Today is the chance'

In fact, "today is the chance" for grain bulls, if they are to pull corn and wheat out of their declines.

US Commodities said: "Corn and wheat are extremely oversold. The market needs to react positive to negative news," if it is to really show bullish credentials.

As an extra help, US corn weekly export sales data came in 380,000 tonnes, old crop and new, above market expectations, and making it the third best week of 2012-13 so far.

And China was reported to have bought a stack of new crop corn too.

'Cut the deficit in half'

However, corn struggled to hold on to positive ground, standing 0.25 cents higher at \$6.91 a bushel, as its fellow grain wheat sank under the weight of snow fallen on needy hard red winter wheat areas.

"The blanket of snow over a large part of the hard red winter wheat area has capped rallies in wheat," Mr Holaday said.

Gail Martell, at Martell Crop Projections, said: "Heavy storm precipitation spells relief in the US heartland where wheat is imperilled by drought.  

"A two-inch moisture deficit had built up in the hard red winter wheat area since early October.  One inch of precipitation would cut the deficit in half."

'Solid exports'

Chicago wheat for March stood 0.3% lower at \$7.19 ¾ a bushel.

And the drop might have been even steeper, but for a strong set of wheat export sales data too, of more than 750,000 tonnes old crop and new - the best figure, but one, in eight months.

"The wheat number was once again solid," Mr Holaday said.

Also offering some support were ideas from the International Grains Council and the USDA that while the world wheat crop may improve sharply in 2013-14, stocks will not see a rebuild.

Earlier, Paris wheat for May closed down 0.3% at E237.50 a tonne, while London wheat for Masy ended down 0.3% at £206.10 a tonne.