A broad-based commodity selloff swept cotton futures along on a rough ride last week amid a re-evaluation of risk as concerns about economic growth mounted and the dollar strengthened.

The lead July contract shed 516 points to 146.86 cents, its lowest close since Jan. 25, for the week ended Thursday and December lost 450 points to 122.08 cents. December posted back-to-back closes below its 50-day moving average.

Weak economic data from the United States and Europe drove world stocks lower and battered commodities. The Reuters-Jefferies CRB index, a global benchmark for commodities, headed for its biggest weekly loss since December 2008 on widespread liquidation.

Growing yarn inventories and stagnant sales in China, the world’s largest cotton consumer and importer, fed worries about demand. Weigiao Textile Co., the world’s largest yarn maker, continued to back off the price it was willing to pay for raw cotton.

Net U.S. old-crop export sales cancellations slowed to 5,100 running bales during the week ended April 28. This was the sixth straight week of cancellations. However, 2010-11 commitments of 15.691 million statistical bales were only marginally below USDA’s export estimate of 15.75 million.

New-crop sales quickened to 74,600 running bales, lifting 2011-12 commitments to a bulging 5.487 million for the marketing year beginning Aug. 1. This is 6.5 times forward sales a year ago of 843,300 bales.

Increased shipments of 432,700 running bales boosted exports for the season to 11.214 million or 11.55 million statistical bales. This is 73 percent of the estimate, against 67 percent of final exports a year ago. Traders looked ahead to USDA’s supply-demand estimates Wednesday. The report will feature the agency’s first official forecasts for 2011-12 and updated estimates for 2010-11.

The International Cotton Advisory Committee said in its supply-demand report that slowing demand seemed mainly responsible for snapping in April a string of seven straight months of rising world cotton prices.

The Cotlook A Index of world values hit a record high of 243.65 cents on March 8 and finished April at 172.70 cents. Prices remain high by historical standards, ICAC noted. The index slid to 168.70 cents Thursday morning ahead of the futures close.

High cotton prices, problems of credit access and the fact that cotton yarn prices did not increase as fast as cotton prices and started yielding ground in mid-March are all affecting mill use, ICAC said.

Global cotton use is projected by ICAC at 115 million bales this season, essentially unchanged from last season. Cotton’s share of world fiber use is declining, ICAC indicated.

Production is forecast to increase by 11 percent to a record 127 million bales in 2011-12, despite early weather problems. Larger supplies will feed demand but high prices and synthetic fiber competition are expected to limit growth in mill use to 3 percent or 119 million bales.

With world production projected to exceed mill use, world ending stocks are expected to rebound to 46 million bales from 39 million estimated for this season.

The world stocks-to-use ratio, forecast at an all-time low of 33 percent this season, could climb to 39 percent in 2011-12, ICAC said. This would remain lower than the 10-year average of 49 percent prevailing before 2009-10.

The Cotlook A Index is expected to average around 165 cents in 2010-11, ICAC said. The secretariat believes the 2011-12 season-average index will drop but probably remain well above the 10-year average of 60 cents.

On the U.S. crop scene, cotton planting advanced five percentage points to 18 percent complete during the week ended May 1, up five a widened six points behind a year ago and the five-year average.

Progress lagged sharply in most of the five-state Delta because of excessive wetness and flooding. Planting trailed the average pace by up to 24 points in some Delta states.

Dry soils retarded progress in top-producing Texas where growers had planted 16 percent of the acreage, down from 24 percent a year ago and 23 percent on average.

Progress was mixed in the Southeast, ranging from as much as eight points ahead of average to 15 points behind, and also in the West at up 10 points to down five points.

On the international crop scene, domestic cotton arrivals in Indian spot markets rose by 2.5 percent through May 1 from a year earlier, according to the state-run Cotton Corp. of India.

The arrivals stood at 28.6 million bales (170 kilograms or 375 pounds), compared with 27.9 million a year ago. The great bulk of the crop is believed likely to have hit gin yards by late May.

Reports have indicated the government will consider permitting more exports only after the new marketing year begins. The decision will hinge on crop prospects. Grower and trader interests have pushed for additional exports this season, a move firmly opposed by India’s textile industry.

Various groups have forecast increases of 10 percent to 14 percent in India’s cotton area this year from an updated USDA estimate of 11.2 million hectares (27.68 18 million acres). A 10 percent increase would put the area at 12.32 million hectares (30.44 million acres).

However, short supplies of Bt cotton planting seeds are expected to result in lower yields.

Meanwhile, speculators increased their net long cotton futures position by half a point to 12.5 percent of the open interest during the week ended April 29, according to the exchange’s spec-hedge report.

The specs liquidated 2,523 longs but covered more shorts, 2,853, raising their net longs by 330 lots to 19,277. Trade interests covered 1,582 short hedges and lifted 1,912 long hedges.

Open interest fell 4,435 lots to 153,644 and declined further to 149,389 lots Tuesday, lowest since October 2009, before rising slightly to 149,712 lots going into Thursday’s session.