Effect of different phosphorus levels on growth and yield of three varieties of cowpea (vignaunguiculata (l) walp) in mubi north local government area, adamawa state, Nigeria

This study determines the Effect of different Phosphorus levels on growth and yield of three varieties of cowpea (VignaUnguiculata (L) Walp) in 2016 rain fed cropping season. Phosphorus is very important for cowpea production in many tropical African soils with inherent low phosphorus fertilizer. Most farmers in this locality do not have access to phosphorus fertilizer. Selection of cowpea lines that produce good yield under low soil phosphorus or those with high phosphorus use efficiency can be a low input approach to solving this problem. This study was conducted at the teaching and research farm of the department of Crop Science, Adamawa State University, Mubi in Northern Guinea Savanna Zone of Nigeria. The experiment consists of three phosphorus levels (27Kgha-1, 36Kgha-1, and 45Kgha-1) and the three cowpea genotype (Red Kanannado, Red Iron and White Kanannado). These treatments in a factorial combination were laid out in a Randomized Complete Block Design and replicated three times. Data were collected on growth and yield parameters. Data generated were analyzed using Duncan’s Multiple Range Test (DMRT). Phosphorus fertilizer significantly enhanced growth and yield characters of the cowpea varieties used; plant height, number of branches, number of effective nodules in all the weeks of measurement were significantly improved. Phosphorus also had a significant effect (p>0.05) on seed yield per treatment, pod length, number of seed per pod, 100 seed weight in all varieties used. However, variations were observed in responses of the different cowpea varieties to phosphorus application. High yield values were observed in variety three; White Kanannado, followed by variety two; Red Iron and variety one; Red Kanannado. Highest value in all the yield characters measured was observed in variety one; Red Kanannado at phosphorus fertilizer rate of 45Kgha-1. When phosphorus is available, Red Kanannado and 45Kgha-1 of phosphorus application rate is recommended.