Weed Control and Response of Peanuts (Arachis Hypogaea) To Chlorimuron1

Abstract

Abstract Experiments were conducted in 1984 and 1985 on a Dothan loamy sand (Plinthic Paleudults) at Headland, Alabama, to evaluate the effects of the ethyl ester formulation of chlorimuron [2-[[[[4-chloro-6-methoxy-2-pyrimidinyl]amino]carbonyl] amino]sulfonyl]benzoic acid] on Florida beggarweed (Desmodium tortuosum (SW) DC.) and sicklepod (Cassia obtusifolia L.) control, and yield and grade of peanuts (Arachis hypogaea L.) Treatments consisted of a factorial arrangement of five chlorimuron rates (17.5, 35.0, 52.5, 70.0 for 87.5 g ai/ha) and four application times, preplant incorporated (PPI), preemergence (PRE), ground cracking (EPOT) or post-emergence over the top (POT). Crop injury, as indicated by visual ratings at 8 weeks after planting (WAP) and yield, was excessive with 52.5 g/ha and higher applied PRE or EPOT and with 35.0 g/ha and higher applied POT. Florida beggarweed control at 8 WAP was good with all rates; however, full season control was unacceptable. Control of sicklepod remained good through the entire season. In a separate study, several herbicide systems utilizing chlorimuron in combination with other herbicides were compared to a standard weed control system. While most herbicide systems which included chlorimuron provided yields comparable to the untreated check, none offered any advantage in terms of weed control and yield over the standard.