US farmers intend to plant the biggest corn acreage since the year Picasso painted Guernica and George Gershwin died, lured by strong returns - and at the expense of soybeans and wheat.
The data sent soybeans to a six-month high in Chicago, where wheat soared 8%, and old crop corn, boosted by a separate inventory report, locked up the exchange maximum.
US growers are to plant 95.9m acres with corn this year, an area bigger than Japan, and the highest acreage since 1937, the US Department of Agriculture said.
"There is a yellow tsunami coming. This is a huge number of acres," Sal Gilbertie, president of commodity-based exchange traded fund specialist Teucrium Trading, told Agrimoney.com.
The estimate, revealed in a long-awaited sowings report, was far bigger than investors had expected, with analysts predicting a figure of at best 95.6m acres, and potentially as low as 93.5m acres.
The extra area will come in part from soybeans, for which sowings were pegged at 73.9m acres, below last year's number and the weakest market forecast.
US futures prices as of 18:45 UK time (12:45 Chicago time)
Chicago wheat: $6.62 ¾ a bushel, +8.2%
Chicago corn: $6.44 a bushel, +6.6%
Minn. wheat: $8.40 ¼ bushel, +6.5%
Kansas wheat: $6.93 ¼ a bushel, +6.0%
Chicago soybeans: $14.11 ¾ a bushel, +4.2%
Chic. corn (Dec): $5.37 ¾ a bushel, +2.6%
Prices for May contracts, except Dec corn
Wheat area, at 55.9m acres, was pegged below expectations too, reflecting a switch by farmers in northern spring wheat states, such as North and South Dakota, where record areas have been allocated to corn.
Indeed, spring wheat seedings in South Dakota are to expected to hit an all-time low.
The switch to corn reflects income prospects from corn, those prices remain at historically high levels.
"Planted acreage is expected to be up in most states compared to last year due to expectations of better net returns in 2012 compared to other commodities," the USDA said.
US sowings estimates, change on last year, and (on market forecast)
Corn: 95.864m acres, +3.943m acres, (+1.144m acres)
Soybeans: 73.902m acres, +-1.074m acres, (-1.491m acres)
All wheat: 55.908m acres, +1.499m acres, (-1.514m acres)
Includes - winter wheat: 41.707m acres, +1.063m acres, (-254,000 acres)
spring wheat: 11.976m acres, -418,000 acres, (-1.337m acres)
The corn market has been kept firm by inventories whose tightness was confirmed in USDA separate data, showing inventories as of the start of this month at 6.01bn bushels.
This was the smallest number in 16 years, and some 140m bushels fewer than analysts had forecast.
Inventories of soybeans and wheat also fell below forecasts, and on year-on-year levels.
On the markets, the data sent prices soaring, led by May corn, which jumped limit up in Chicago, a rise of $0.40 a bushel, on the data showing smaller-than-expected corn stocks.
"What this shows is steady demand for corn, even during a period of higher prices," Mr Gilbertie said.
US stocks data March 1, change on last year, and (on market forecast)
Corn stocks: 6.009bn bushels, -514m bushels, (-140.7m bushels)
Soybeans: 1.372bn bushels, +123.4m bushels, (-14.7m bushels)
All wheat: 1.201bn bushels, -224.6m bushels, (-22.3m bushels)
Sources: USDA, ThomsonReuters poll
The performance pulled the new crop December lot higher despite prospect of higher sowings.
In Minneapolis, the home of trading in US spring wheat, the May lot soared 6% on thoughts of spring wheat area, excluding durum, of 12.0m acres, more than 1m acres below expectations.
While the report was less directly supportive of Chicago soft red winter wheat, a 4% rise in the benchmark May lot was seen as reflecting a rush by speculators to close a huge net short position.
'Most explosive commodity'
Oilseed prices soared too, with the data signalling disappointing US soybean sowings on top of a drought-hit South American harvest.
"The report is all about the soybeans. They are the most explosive commodity on the board," FCStone said.
"Global oilseed supplies are now projected extremely tight and will require demand-rationing price levels."
In Paris, rapeseed closed 1.8% higher at a 14-month high, for a spot contract, of E490.75 a tonne.
Not in the bag yet...
The USDA estimates were based on a survey of more than 84,500 farmers from throughout the US, and is thus viewed as an accurate assessment of grower intentions.
However, analysts warned over the potential for farmers to change their plans between the date of the survey, in the first two weeks of March, and planting.
EU futures closing prices
Paris wheat: E212.75 a tonne, +2.7%
London wheat: £174.75 a tonne, +2.2%
Paris rapeseed: E490.75 a tonne, 1.8%
Prices for May contracts
"In the second half of March, corn prices for both old and new crop have fallen by 8-10% while soybeans have declined just 1-2%," Paul Deane at Australia & New Zealand Bank said.
Regardless of the estimates, investors were still "left partially guessing as to what current price relativities mean for US planted acres".
At Societe Generale, Michael Haigh said recent price rises in soybeans had increased their appeal in particular for growers had been thinking on not rotating out of corn this year, offering the likelihood of weaker yields.