Performance of paraquat and sethoxydim in arracacha

Abstract

Field experiments were conducted at the Adjuntas Agricultural Experiment Station of the University of Puerto Rico during 1996 and 1998 to evaluate the efficacy of the herbicides paraquat and sethoxydim on arracacha. In 1996, no differences were found among the treatments for weed control four weeks after the first and second herbicide applications. Weed control ranged from 72% (two applications of sethoxydim) to 87% (hand weeding) at four weeks after herbicide application, and from 43% (one application of paraquat) to 97% (two applications of paraquat) at four weeks after the second herbicide application. There were no significant differences in yield between treatments with two applications of paraquat and that of hand weeding.The lowest yield (7,632 kg/ha) was obtained when sethoxydim was applied once. In the 1998 experiment, no differences in weed control were found among treatments at four weeks after the first herbicide application; weed control ranged from 81% (two applications of sethoxydim) to 98% (hand weeding). When rated at four weeks after the second herbicide application, the lowest weed control (84%) was obtained with one late application of paraquat. There were no significant differences in yield and number of corms per hectare among treatments.