Accepted 6th July, 2016
The production package is blanket for cow pea in Ethiopia until recently. To address the problem of lack of location specific production packages for cowpea, field experiments were conducted during the rainy seasons of 2014 and 2015 with objective of evaluating the yield and agronomic performance of cowpea varieties under varying row spacing and DAP (Diammonuim phosphate) application rates. The experiments consisted of four levels of P2O5 in the form of DAP (0, 23, 46 and 69 kg P2O5 ha-1) and four row spacing (40, 50, 60 and 70 cm). The sixteen treatment combinations were laid out in a randomized complete block design with three replications. The results of two way interaction showed that number of pods per plant, plant height, seed yield per unit area, 100 seed weight and biomass yield per unit area were significantly increased due to 40 cm row spacing in all the years of the experiment. Similarly, there was significant (P<0.05) increase in plant height, pods/plant and grain yield/m2due to 50kg/ha DAP, the result of which was invariable to 50 to 200kg/ha DAP. Wider to intermediate rows and higher fertilizer rates produced highest hundred seed weight (HSW) where as HSW was lowest due to narrower rows and lower fertilizer rates. Therefore, production of cow pea in Amaro and Hawasa areas may be carried out using 40 cm row spacing and 50 kg/ha DAP both in belg and meher seasons.
Keywords: Cow pea, diammonium phosphate, row spacing, grain yield, biomass yield, package