Commodities fell broadly Tuesday as forecasts for slower-than-expected growth in the third quarter prompted investors to trim risks. The dollar's rise against the euro also weighed on raw materials prices as those holding the single European currency were less compelled to pay more for dollar-denominated commodities. The Reuters-Jefferies CRB, a basket of 19 mostly U.S.-traded commodity futures, finished at a one-week low as oil, copper, corn and