Exchange traded notes that follow cotton and sugar prices have been among the leaders during the commodity boom the past couple years, but now they are moving in opposite directions.

After trading steadily lower through most of 2011, iPath Dow Jones-UBS Sugar ETN (NYSEArca: SGG) has rebounded nearly 20% over the past month and is among the top performers for the period.

A nearly 3% rally on Thursday pulled the sugar ETN above its 200-day moving average, a closely watched technical indicator.

Sugar prices are expected to remain higher this decade after a recent 30-year peak, but will see swings tied to government policies in India and conditions in Brazil, a top producer and exporter, Reuters reported Friday.

Conversely, iPath Dow Jones-UBS Cotton ETN (NYSEArca: BAL) is among the steepest decliners over the past four weeks with a more than 10% pullback. It crashed below its 200-day average on Thursday after suffering a nearly 5% loss for the session.

The House of Representatives on Thursday voted to reject sending an annual $147 million subsidy for Brazilian cotton farmers.