Productivity of millet/cowpea intercrop as affected by cowpea genotype and row arrangement

Six cowpea genotypes (Danila, IT96D-772, IT90K-277-2, IT95K-1091-3, IT96D-740, IT96D-757) were intercropped with a local millet cultivar using four row arrangements (1:1, 1:2, 2:2 and 2:4 millet to cowpea rows) in a field experiment conducted at Minjibir near Kano in the Sudan savanna ecological zone of Nigeria during the 1999 and 2000 wet seasons. Cowpea genotypes and row arrangement had no effect on the grain yield, yield attributes and partial LER of millet. However, millet panicle weight per m was significantly lower at 1:1 and 2:2 2 row arrangements compared to 1:2 and 2:4 arrangements in 2000. Mean cowpea grain yield was reduced by 47% as a result of intercropping with millet. Intercropped cowpea grain yield varied from 472 to 861 kg/ha, with IT90K-277-2 recording the highest grain yield and partial land equivalent ratio (LER). Grain yield and partial LER of cowpea were significantly higher at 2:4 row arrangement compared with the other row arrangements in both seasons. The highest total LER (1.26) and gross monetary return were obtained using the dual purpose improved medium maturing photoperiod insensitive genotype, IT90K-277-2. Row arrangement had no significant effect on the total LER in 1999 whilst in 2000 total LER was higher at 2:4 row arrangement relative to the other arrangements. In both seasons, the highest gross monetary return was obtained from 2:4 row arrangement.