Field experiments were conducted in 1992 and 1993 on loamy sand soils heavily infested with purple nutsedge (Cyperus rotundus L.) to evaluate nutsedge control with systems integrating Zorial (norflurazon), MSMA, and cultivation. Zorial at 1.0 lb ai/A was applied preplant incorporated (PPI), preemergence (PRE), or split with half PPI and half PRE. Each Zorial treatment was present with and without MSMA applied early and late postemergence-directed at 2.0 lb ae/A. All plots were cultivated two or three times. The results demonstrated good season-long control of purple nutsedge with a system utilizing Zorial applied PPI, MSMA applied twice postemergence-directed, and cultivation. Late-season control in the absence of MSMA, averaged over years, was 11, 34, and 50% with Zorial applied PRE, split, and PPI, respectively. When followed by MSMA, nutsedge control with Zorial applied PRE, split, and PPI was 81, 91, and 97%, respectively. Control with MSMA alone was 83%. Seedcotton yields averaged 1670, 1970, and 2120 lb/A with Zorial applied PRE, split, and PPI, respectively, and 2010, 2240, and 2320 lb/A, respectively, when followed by MSMA. Yield of the untreated check was 995 lb/A while the yield with MSMA alone was 1830 lb/A.

An experiment was conducted in 1993 to evaluate control of purple nutsedge with Zorial, Staple (DPX-PE350), and MSMA. Treatments included a factorial arrangement of 0 and 1.0 lb/A of Zorial applied PPI, 0 and 1 lb/A MSMA applied postemergence over-the-top, and Staple at 0, 1, and 2 oz ai/A applied postemergence over-the-top of cotton in the one-leaf stage and nutsedge 2 to 4.5 inches tall. All plots were cultivated twice. Late-season control with Zorial alone, MSMA alone, or Zorial plus MSMA was 10% or less. Control with 1 and 2 oz/A of Staple was 22 and 33%, respectively, without Zorial and 26 and 53%, respectively, with Zorial. Adding MSMA to either rate of Staple did not improve control. There were no interactions between Zorial, Staple, and MSMA for yield. Main effects for Zorial and MSMA were not significant. Averaged over Zorial and MSMA variables, seedcotton yields with 0, 1, and 2 oz/A of Staple were 1050, 1685, and 1770 lb/A, respectively.