Evaluation of Effects of Plant Population on the Performance of Cowpea in the Guinea and Sudan Savanna of Nigeria.

Field experiments were conducted in 2013–2014 in Minjibr (Sudan Savanna)  and Zaria (Northern Guinea Savanna) in northern Nigeria to evaluate  how  cowpea plant population    affect crop performance. Comparisons were made of plant populations of  133,333, 266,666 and 399,999 plants ha^-1.  Data included intercepted active radiation (IPAR), leaf area index (LAI), total dry matter, pods m^-2, seed m^-2, 100 seed weight, grain and fodder yield of cowpeas. Results show that plant populations of 266,666 and 399,999 plants ha^-1 gave higher crop performance in terms of light interception, biomass production and yield and yield components for all cowpea varieties. Although the late/medium maturing varieties (IT99-K-573-1-1 and IT99K-573-2-1) performed better than the  early maturing varieties (IT93K-452-1-1 and IT98K-205-8), all the varieties responded similarly to plant populations. Results show that the current cultivation of cowpea at population of 133,333 was not confirmed to be optimum for cowpea production.