Field studies in 1999 evaluated the use of the pre-emergence herbicides Prowl and Treflan and the postemergence herbicides Staple and Roundup Ultra (in conjunction with Roundup Ready cotton) for weed control in ultra narrow row cotton in Arizona. Prowl at 2.4 pints per acre or Treflan at 0.75 pound active ingredient per acre followed by Roundup Ultra at 1 quart per acre at the three to four true leaf stage provided good to excellent weed control. A preplant incorporated application of Prowl at a low rate was as effective as either of the preplant incorporated Prowl rates or preplant incorporated Treflan rates. A sequential postemergence topical application of Staple following the application of Roundup Ultra did not improve weed control. Preplant incorporated Prowl or Treflan application followed by a postemergence topical Roundup Ultra application provided acceptable weed control in fields with low to moderate weed pressure. Difficult to control weeds, such as nutsedge, may require additional applications of Roundup Ultra. 1 ref.