Field trials were conducted across the cotton belt in 1996 to evaluate the tolerance of Roundup Ready® cotton (Gossypium hirsutum L.) to various topical and post-directed applications of Roundup® Ultra(glyphosate) herbicide. Current label recommendations limit topical applications to 0- to 4-leaf cotton. After the 4-leaf stage, applications must be post directed at the base of the cotton plant. All trials were replicated small-plot studies maintained weed free by including a full residual herbicide program.