April 29 (Bloomberg) -- Rice plunged the most in three weeks after a government report showed planting of the U.S. crop accelerated, easing concern that global food supplies will lag behind demand.

About 44 percent of the U.S. crop was planted as of April 27, compared with 26 percent a week earlier and 56 percent a year earlier, the U.S. Department of Agriculture said yesterday. The average for the date from 2003 to 2007 is 58 percent. About 20 percent had emerged from fields versus 30 percent a year ago.

The cereal, the staple food for half the world, has tumbled for four days, declining 7 percent, after doubling in a year as China, Vietnam and India curbed exports. Record prices stoked social tension in Asia and Africa and prompted Wal-Mart Stores Inc.'s Sam's Club to limit purchases of jasmine, basmati and long-grain white rice in U.S. stores.

``Supplies of the grain are sufficient, but there was a bottleneck because of speculative hoarding in some countries,'' Nicholas Chung, senior manager at Korea Development Bank, said by phone today from Seoul.

Rice for July delivery fell as much as 74.5 cents, or 3.2 percent, to $22.935 per 100 pounds in after-hours electronic trading on the Chicago Board of Trade, the biggest intraday decline since April 8. The commodity traded at $23.155 at 6:13 p.m. Singapore time.

The cereal has fallen from a record $25.07 per 100 pounds April 24 after Thailand and Brazil said they won't curb exports and Pakistan announced plans to sell 2.5 million tons of the grain, easing concern that global supplies were short.

Vietnam Supplies

Vietnam, the second-biggest supplier after Thailand, said April 27 it will produce enough to meet demand from exporters and local consumers, and banned speculators from the domestic market to help stem price increases.

``Our rice output this year will be sufficient for consumption and export,'' Prime Minister Nguyen Tan Dung said in a statement posted on the government's Web site. Brokers and anyone not involved in the food business will be immediately banned from speculating on rice prices, he said.

Thailand will gradually sell 2.1 million tons of the grain stored in state warehouses to domestic consumers as the government tries to keep a lid on soaring prices, Prime Minister Samak Sundaravej told reporters today in Bangkok.

The country hasn't limited overseas sales and plans to ship 9 million tons this year, raising concern that there may not be enough local supply to keep down prices. The government plans to rebuild stockpiles with supplies from the new harvest.

UN Call

United Nations Secretary-General Ban Ki-moon said today he will chair a new UN task force to tackle the crisis provoked by soaring food prices.

The crisis is an ``unprecedented challenge'' that has ``multiple effects on the most vulnerable,'' Ban told a press conference in the Swiss capital Bern. ``We must feed the hungry,'' and ``full funding'' is needed, he said.

Ban is attending a two-day meeting with UN development agencies. Rising food prices are creating the biggest challenge the UN World Food Program has faced in its 45-year history, ``threatening to plunge more than 100 million people on every continent into hunger,'' the agency said on April 22.

Global food prices surged 57 percent last month from a year earlier, according to the UN, and the World Bank warns civil disturbances may be triggered by rising food prices in 33 countries.

To contact the reporter for this story: Jae Hur in Singapore at jhur1@bloomberg.net

Last Updated: April 29, 2008 06:49 EDT