This research was conducted to determine the effectiveness of the herbicides glyphosate (1.800 g ha-1) and paraquat (800 g ha-1), applied as desiccants before sowing and fenoxaprop-p-ethyl (0, 40, 80 and 120 g ha-1) and imazamox (0, 21, 42 and 63 g ha-1), applied in post-emergence conditions, on the weed control and the phytotoxicity to cowpea plants (Vigna unguiculata cv. Epace 10), under a no-till system, with furrow irrigation. A randomized complete block design with a split-split-plot design and four replications was used. The treatments with glyphosate associated with imazamox or fenoxaprop-p-ethyl was more efficient in controlling weed, showing reduced shoot weed dry biomass production, when compared to paraquat combined with the post emergence herbicides. The herbicides fenoxaprop-p-ethyl and imazamox did not cause visual phytotoxicity symptom to the cowpea plants. The best post-emergence weed control was provided by fenoxaprop-p-ethyl at the rate of 80 g ha-1, associated to glyphosate (1.800 g ha-1). The fenoxaprop-p-ethyl was effective in controlling the grass weeds, but Cenchrus echinatus and Digitaria horizontalis. Imazamox was not effective in controlling the broadleaf weeds Chamaesyce hirta and Euphorbia heterophylla at the studied rates.
Vigna unguiculata; herbicides; grain yield
