Story highlights: The impact of the months-long climb is leading to higher retail coffee prices on several major brands This week's rally appears to be largely due to speculative trading because fears have eased about weather and supply issues Sen. Charles Schumer, D-N.Y., says he wants U.S. Trade Representative Ron Kirk to warn some major coffee growers in Brazil and Vietnam not to stockpile their crops. He said that could boost coffee futures contracts even more. ---- By Sandy Shore Associated Press September 8, 2010 Coffee prices hit a 13-year high Wednesday, extending a rally that has sent prices up about 43 percent in the past three months. Coffee for December delivery settled up 2.25 cents at $1.9455 a pound Wednesday after hitting $1.9865 per pound earlier in the day. Trading volume was light, which can exaggerate price movements. The impact of the months-long climb is leading to higher retail coffee prices on several major brands, including Folgers, Dunkin...