A material used to kill weeds. In cotton, the material usually is characterized by (1) timing: “PPI” (prior to planting and incorporated), “pre” (prior to plant emergence from soil), and “post” (after plant emergence); or by (2) application type: “broadcast” (applied evenly over an area), “banded” (applied over a portion of the total area), or “directed” (targeted at a specific area), usually toward the base of the cotton plant.