Modelling the Dual Potential of Cowpea in the Lawra-Yagtuuri in the Upper West Region

Aims: This research was conducted in pot of trials at the farm land of Lawra-Yagtuuri in the Upper West Region to determine the effect of Rhizobia inoculants, Boostxtra, and appropriate Phosphorus Fertilizer level required for cowpea growth and yield.

Study Design: The research design used in this study was experimental. Specifically, the experiment was run as a split-plot design.

Place and Duration of Study: Department of Statistics and Department of Mathematics, University for Development Studies, between November, 2015 and July, 2016.

Methodology: The experiment assessed the effects of rhizobia inoculants at two levels (2.5 g and 5.0 g) per kg, boostxtra and four levels of phosphorus fertilizer (0 kg P2O5 ha-1, 25 kg P2O5 ha-1, 50 kg P2O5 ha-1and 75 kg P2O5 ha-1) on the growth and yield of cowpea. It was run in a split-plot design. The analysis was done using Generalized Linear Model and Subset Regression.

Results: Phosphorus Fertilizer and Boostxtra significantly enhanced cowpea growth and yield; Pod weight plant (g), Nodule dry weight (g), Pod and Nodule numbers in all the weeks of measurement were significantly improved. However, the highest yield was observed at 50 kg P2O5 ha-1. Cowpea response to rhizobia inoculation was not sufficient to raise cowpea yield. The model was significant (P<0.05) accounting for 77.70% of total variation in the yield. The subset regression analysis had C(p)=5.28 from six variables in the model with the Adjusted R Square = 0.9318.

Conclusion: The ability to optimize cowpea grain yield depends on the application of 50 kg P2O5/ha and Boostxtra and care should be taken to apply the right amount of Phosphorus Fertilizer.