Yellow nutsedge (Cyperus esculentus) control in peanut (Arachis hypogaea) as influenced by method of metolachlor application

Field studies conducted from 1989 through 1991 evaluated methods of metolachlor application including POST followed by irrigation for yellow nutsedge control and peanut response. Metolachlor PPI stunted peanut in two of three years while metolachlor applied at emergence, 10, 20, or 30 days after peanut emergence (DAE) caused no peanut injury. Metolachlor 20 DAE provided > 95% yellow nutsedge control. Metolachlor soil-applied and again POST controlled yellow nutsedge at least 70%; however, some peanut stunting was noted. Bentazon plus metolachlor at 2.24 kg ai/ha controlled yellow nutsedge at least 92% when applied 30 DAE. Peanut yields were consistently the highest with metolachlor PRE at 1.40 kg ai/ha followed by a POST application of 1.40 kg ai/ha at 45 DAE.