This work aimed to determine the periods of weed interference in cowpea (Vigna unguiculata), sown under the conventional system in July 2007. The experiment was arranged in randomized blocks, with the treatments consisting of periods of control or intercropping of the weeds with the crop. In the first group, the bean crop remained free of weed interference in the periods 0-09, 0-18, 0-27, 0-36, 0-45 and 0-60 (harvest). .In the second group, the bean crop remained under interference from the time of emergence up to the same periods previously described. The critical period of weed interference prevention (CPIP) was from 11 to 35 days after crop emergence. Weed interference reduced the final stand, number of pods per plant, and grain yield up to 90%.
Vigna unguiculata; competition; yield
