Weed Control in Peanut (Arachis hypogaea L.) Using Carfentrazone plus Pyroxasulfone Herbicide Systems

Abstract

Field studies were conducted during the 2017 through 2019 growing seasons in Texas and Oklahoma to determine weed control when using herbicide systems containing the pre-mixture of carfentrazone plus pyroxasulfone (C + P) applied preemergence (PRE), early postemergence-peanut cracking (EPOST), or postemergence (POST). When pendimethalin was not used as a base PRE herbicide treatment, C + P applied PRE controlled Texas millet [Urochloa texana (Buckl.)] ≤75%; however, the addition of pendimethalin to C + P applied PRE increased control to >85%. Palmer amaranth (Amaranthus palmeri S. Wats.) control was >70% with most C + P systems while smellmelon (Cucumis melo L. var. Dudaim Naud.) control was never <97% with any C + P system. Pitted morningglory (Ipomoea lacunose L.) control in systems with C + P applied either PRE or POST was never <79% while ivyleaf morningglory (Ipomoea hederacea Jacq.) control with C + P systems applied PRE varied from 73 to 90%, applied EPOST from 53 to 95%, and POST from 84 to 98%. The use of the premix of C + P provided excellent season—long residual control of several broadleaf weeds including Palmer amaranth, smellmelon, and morningglory spp. This herbicide mixture offers peanut growers another option to control ALS- and glyphosate-resistant Palmer amaranth, which is becoming a major problem in many areas of Texas and Oklahoma.