The price of cotton is dropping as traders worry that slower economic growth will reduce consumers' demand for clothes and other goods made from the material.
Cotton for December delivery dropped 3.1 percent Tuesday finish at 71.05 cents per pound. The price has fallen nearly 29 percent in the past 12 months.
There are bountiful global supplies of cotton. At the same time, economies are slower in the U.S., Europe and China. That gives mills an advantage because they can wait until they get orders before they buy cotton.
Other commodities are mixed after Federal Reserve Chairman Ben Bernanke stopped short of saying the central bank would step in to support economic growth.
Prices are higher for oil, wheat, platinum and palladium.
Gold, copper, corn and soybeans are lower.