Corn regained its lead by the close of trade on Friday, jumping 3%, while its grain partner wheat struggled against a stronger dollar.
The Midwest snowstorms remained one reason for investors to get bullish on the grain, with somewhere around 1.5bn bushels yet to harvest, some of which may now have to wait until next year to get in the silo.
"The market is beginning to respect the fact that roughly 680m bushels of corn is in eight inches or more of snow," US Commodities, the broker said.
But technical factors also played their part, with corn for March getting back above both its 200-day moving average of $3.97 a bushel, and the psychologically imported $4 a bushel mark.
The contact ended 11.5 cents higher at $4.04 ½ a bushel in Chicago.
Other crops had more difficulty facing down a dollar which has now begun rising on good US data – on hopes for economic revival – as well as the poor data which ironically helped it before, as investors opted for a currency viewed as a safe haven in tough times.
Friday bought upbeat US retail sales data and statistics showing an improvement in American consumer confidence.
That helped the dollar strengthen to below $1.46 against the euro for the first time since October.
Wheat for March only just managed a positive close, ending up 0.5 cents at $5.37 ½ a bushel.
Soybeans did a little better, closing up 8 cents at $10.35 a bushel, helped by a fresh order of 232,000 tonnes by China.
The currency moves helped European wheat, at least, with Paris ending E0.75 a tonne higher at E128.75 a tonne for January.
London wheat for the same month jumped £1.95 to £107.10 a tonne.
Not that farmers should get too excited, to judge by comments from Hugh Schryver at grain merchant Glencore.
"For what little business is being done, UK feed wheat is currently €2-3a tonne too expensive against shipments from the European Black Sea – that's Romania and Bulgaria"