Effect of NPK (12:12:17) Fertilizer Rates on the Growth and Yield of Cowpea (Vigna unguiculata) Varieties

G N Nwokwu

doi:10.7176/jbah/10-2-03

Abstract

Field experiments were carried out as 3 x 4 factorial at the faculty of Agriculture and Natural Resources Management, Ebonyi State University, Abakaliki in 2016 and 2017 cropping seasons to study the effect of NPK (12:12:17) fertilizer rates on the growth and yield of cowpea varieties ( Vigna unguiculata ). Results revealed that fertilizer application resulted in significant improvement in plant height, number of leaves per plant, leave area index and reduced days to flowering. Yield components and grain yield were significantly enhanced by the application of fertilizer at 150 kg ha -1 but varietal effect indicated differential varietal responses to fertilizer application which had significantly practical implications for field production. It was therefore concluded that the application of fertilizer to cowpea is beneficial although in small quantity and genotype dependent. There were positive and significant correlation among growth and yield characters except days to 50% flowering that was negatively correlated. Keywords : Cowpea, Fertilizer, Growth, NPK, Varieties, Yield. DOI : 10.7176/JBAH/10-2-03 Publication date: January 31 st 2020

Highlights

Cowpea (Vigna unguiculata L walp) is a tropical annual herbaceous legume which belong to the family papilionaceae (Fabaceae) order Leguminosae and genus Vigna (Singh et al, 1997)
Despite its great importance, grain yield of cowpea crop is low, around 300 kg ha-1 compared with many other crops, the cowpea has received little attention from plant breeders and a large efforts needs to be made to break the yield barriers and if cowpea production is to keep pace with the other crops, especially cereals, its yield potential must be improved (Anonymous, 2004)
Growth attributes such as plant height, leaf area index, number of leaves and Days to 50% flowering were significantly increased by the application of NPK fertilizer

Summary

Introduction

Cowpea (Vigna unguiculata L walp) is a tropical annual herbaceous legume which belong to the family papilionaceae (Fabaceae) order Leguminosae and genus Vigna (Singh et al, 1997). The genus Vigna consist of over hundred different species widely found in the tropical and subtropical regions and has great morphological and ecological diversity It is an important food grain legume for over 200 million people in the dry savanna of tropical Africa. The grain is a good source of human protein, while the haulms are valuable source of livestock protein (Fatokun, 2002) It is a source of income for many smallholder farmers in sub-Saharan Africa and contributes to the sustainability of cropping systems and soil fertility improvement in marginal lands through provision of ground cover and plant residue, nitrogen fixation and suppressing weed. The steady decline in food production due to reduced length of fallow on land has prompt farmers to amend soil with different materials such as organic and inorganic in order to enhance plant growth and increase yield (Adepetu, 1997). Cowpea symbiotically fixes nitrogen, plant dependent on symbiotically fixed N may well suffer from temporary N deficiency during the seedling growth once the cotyledonary reserves have been exhausted

Materials and Methods

Result and Discussions

Findings

Conclusion