Effects of cowpea living mulch on weed control and maize yield

Field experiments were conducted in 2009 and 2010 in research station of college of agriculture, Shiraz University of Iran, to evaluate the effects of cowpea (Vigna unguiculata L.) living mulch on weed suppression, maize (Zea mays L.) grain yield and yield components. Treatments were cowpea living mulch densities (7, 15, 22 and 30 plants m-2), suppression periods of cowpea growth with 2,4-D (30, 45, 60, 75 and 90 days after maize planting), and two control treatments, a weed free and a weedy check. Results of both years showed that cowpea densities significantly controlled weeds. The lowest weeds biomass and the highest maize grain yield were obtained from 30 and 22 plants m-2 of cowpea living mulch density, respectively. In both years, the lowest weeds biomass and the highest maize grain yield, in comparison to the weedy check, were obtained when cowpea growth was terminated 90 and 75 days after maize planting, respectively. It is concluded that, to achieve the highest maize grain yield and yield components and to suppress the weeds, cowpea living mulch at 22 plants m-2 and suppression period of cowpea at 75 days after maize planting, is recommended as a step toward sustainable agriculture