A grennhouse experiment was carried out to evaluate the effect of 10 days water stress (Yw values of ³2.6; -2.2 -0.35, and -0.2 MPa) on the efficacy of pos-emergent application of halosulfuron (150g c.p./ha+Aterbane 0.25% v/v) in the control of purple nutsedge. When the suitable water supplying began in a period of 24 hours after the herbicide spraying, halosulfuron gave an excellent control of purple nutsedge under every water stress conditions. When the suitable irrigation conditions began 48 hours after herbicide spraying, there was a lower halosulfuron efficacy. When the stress was lower than -2.0 MPa, the herbicide gave a good control, mainly in the Yw of -0.35 MPa.
Cyperus rotundus; sulfonylureas; water