Determination of optimal sowing date for cowpea (Vignaunguiculata) intercropped with maize (Zea mays L.) in Western Gojam, Ethiopia

The experiment was laid using four cowpea sowing date to determine optimum intercropping date of cowpea with maize and its effect on maize grain yield and forage biomass yield in South Achefer and Jabitehnan districts of west Gojjam zone, Ethiopia. Each experimental plot had an area of (36m 2).One cowpea (9333) and maize (BH-660) for both districts using four replication in randomized complete block design was used. During planting 200 kg/ha diammonium phosphate (DAP) and after 45 days 200kg urea was applied. Cowpea intercropped simultaneous with maize gave significantly (P<0.01) higher dry matter yield 1.06 and 1.78t/ha as compared to the three intercropping dates 0.84, 0.66, 0.43 and 0.77, 0.45, 0.31 in South Achefer and Jabitehnan districts respectively. Maize grain yield, cob per plant and maize stover yield were not affected by cowpea intercropping date in both districts. This study showed that cowpea intercropped simultaneously with maize could be optimum sowing date for better dry matter yield of cowpea without affecting maize grain yield devoid of experience of shilshalo (cultural practice by farmers) in the study areas.
Keywords:Cowpea, dry matter yield, intercropping date, maize grain yield