Influence of water regimes and herbicides for control of purple nutsedge (Cyperus rotundus)

Background: Purple nutsedge is a weed that has a tough profuse underground tuber system, and is predominantly a perennial species in many crops. Objective: To evaluate the influence of different water regimes to the effectiveness of herbicides used for controlling the purple nutsedge. Methods: Experiment was arranged in a Randomized complete block design (RCBD) with a two-factor factorial design and three replications. The net-house tests were conducted with six treatments and two different water regimes of "watered daily" and "watered weekly". The tested herbicides were florpyrauxifen-benzyl, halosulfuron-methyl, 2,4-D and glyphosate. Results: Water shortage reduced the weed control efficacy of four tested herbicides. Herbicide efficacy improved when plants were watered daily, the high level of sedge biomass reduction at 60 DAT observed in florpyrauxifen-benzyl (30 g ai ha(-1)) and halosulfuron-methyl (50 g a.i ha(-1)) treatment. Glyphosate (480 g ai.ha(-1)) and 2,4-D (360 g ai.ha(-1)) exhibited moderate control efficacy on purple nutsedge under daily watered condition. Conclusions: The water regime was a critical component of purple nutsedge herbicide control program. Maintaining soil moisture by watering daily improved the herbicide efficiency and reliability for the management of purple nutsedge.