Cotton fell to a six-week low after exports from the U.S., the world’s largest shipper, tumbled 72 percent.

U.S. cotton sales dropped to 69,498 bales in the week ended April 7, from 251,501 bales a week earlier, as shipments decreased to China, Bangladesh and other Asian countries, the Department of Agriculture said today. Prices have more than doubled in the past 12 months as demand surged in China, the biggest consumer.

“The numbers show that there has been some demand destruction,” said Gary Raines, an economist at FCStone Fibers & Textiles in Nashville, Tennessee. “It will be a big cause of concern if exports continue to dip over the next few weeks.”

Cotton futures for July delivery dropped 2.64 cents, or 1.5 percent, to settle at $1.78 a pound at 2:47 p.m. on ICE Futures U.S. in New York. The price earlier touched $1.7693, the lowest since Feb. 25.

The fiber dropped 19 percent since reaching a record $2.197 on March 7.