Texas Panicum (Panicum texanum) Control in Peanuts (Arachis hypogaea) with Paraquat

Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) was applied to peanuts (Arachis hypogaeaL. ‘Florunner’) for Texas panicum (Panicum texanumBuckl. # PANTE) control at 0.07, 0.14, and 0.28 kg ai/ha under five application schedules; a single application at 0, 1, 3, or 5 weeks after ground cracking, or multiple applications at 1 + 5 weeks or 1 + 3 + 5 weeks after ground cracking. Peanuts were planted at two different times (normal and late). A herbicide application at the third week (normal planting), or the third or fifth week after ground cracking (late planting) provided acceptable Texas panicum control. Control generally increased with rate. However, increasing paraquat rates with single applications on late-planted peanuts or multiple applications to normal- and late-planted peanuts tended to reduce yield and grade. A single application of 0.07 or 0.14 kg/ha applied the third week after ground cracking consistently provided the best balance between Texas panicum control and crop safety.