Field experiments were conducted at the West Florida Research and Education Center near Jay, FL in 1997, 1998, and 1999. Cotton ‘DP 5415 RR' was planted first week of May in each year and the entire site of each experiment received pendimethalin at 0.84 kg/ha PPI and fluometuron at 1.7 kg/ha PRE. In the first study glyphosate and MSMA herbicide programs were evaluated to determine the effect of long-term purple nutsedge (Cyperus rotundus) control and tuber populations. Treatments were conducted on the same plots in each year. Herbicide treatments included an untreated check; glyphosate at 1.12 kg/ha POST over-the-top at 4 leaf cotton followed by (fb) glyphosate at 1.12 kg/ha POST-directed; norflurazon at 1.7 kg/ha PRE fb MSMA at 2.24 kg/ha plus cyanazine at 0.85 kg/ha POST-directed; norflurazon at 1.7 kg/ha PRE fb MSMA at 1.12 kg/ha POST over-the-top at 4 leaf cotton fb MSMA at 2.24 kg/ha plus cyanazine at 0.85 kg/ha POST-directed; and an untreated check. Herbicide treatments were split-plot in design (cultivation vs. no cultivation) with early-season cultivation as the main effect.