The growing season has just begun and pigweed is spreading quickly, towering above the plants, and crowding out sunlight. This new breed of pigweed is resistant to herbicides. Scientists estimate that thousands of acres have already been plowed back, and that it could cost $20 an acre to fend off the weed.

USA Today, July 18, 2008 How will the cost of growing cotton change? What effect will this weed have on the cotton market in the short run? How will the cotton market change in the long run?