Efficacy of Roundup Ultra for control of common lambsquarters (Chenopodium album), prickly sida (Sida spinosa), and velvetleaf (Abutilon theophrasti) is sometimes low while Command 3ME readily controls these weeds preemergence. Likewise, Command 3ME is poor on pigweed species (Amaranthus spp.) which can be controlled with Roundup Ultra. Treflan is commonly used PPI for grass and small-seeded broadleaf weed control in cotton (Gossypium hirsutum) but requires incorporation which is costly and may delay planting in wet years. Since Command 3ME PRE seems to fit well with Roundup Ultra systems, our objective was to evaluate Command 3ME PRE versus Treflan 4EC PPI in systems for weed control in Roundup Ready cotton. The study was conducted at Rocky Mount, NC in 1997. Treatments included: Command 3ME PRE at 1.3 pints/A (Command), Treflan 4EC PPI at 1 pint/A (Treflan), Command or Treflan followed by (fb) Roundup Ultra at 1.5 pints/A (RU), Command or Treflan fb Cotoran 4L PRE at 2 pints/A (Cot), Command or Treflan fb Cot fb RU, Command or Treflan fb RU fb Bueno 6 at 2.7 pints/A + Bladex at 1.6 pints/A Layby (layby), and Command or Treflan fb Cot fb RU fb layby.