Growth and Yield Responses of Cowpea to Inoculation and Phosphorus Fertilization in Different Environments

Abstract

Cowpea (Vigna unguiculata) is a major source of dietary protein and essential component of the cropping systems in semi-arid regions of Sub-Saharan Africa. However, yields are very low due to lack of improved cultivars, poor management practices, and limited inputs use. The objectives of this study were to assess the effects of rhizobia inoculant and P on nodulation, N accumulation and yield of two cowpea cultivars in Mozambique. Field study was conducted in three contrasting environments during the 2013/2014 and 2014/2015 seasons using randomized complete block design with four replications and four treatments. Treatments consisted of seed inoculation, application of 40 kg P2O5 ha-1, inoculation + P, and a non-inoculated control. The most probable number (MPN) technique was used to estimate the indigenous bradyrhizobia populations at the experimental sites. The rhizobia numbers at the sites varied from 5.27 × 102 to 1.07 × 103 cells g-1 soil. Inoculation increased nodule number by 34–76% and doubled nodule dry weight (78 to 160 mg plant-1). P application improved nodulation and interacted positively with the inoculant. Inoculation, P, and inoculant + P increased shoot dry weight, and shoot and grain N content across locations but increases in number of pods plant-1, seeds pod-1, and 100-seed weight were not consistent among treatments across locations. Shoot N content was consistently high for the inoculated plants and also for the inoculated + P fertilized plants, whereas the non-inoculated control plants had the lowest tissue N content. P uptake in shoot ranged from 1.72 to 3.77 g kg-1 and was higher for plants that received P fertilizer alone. Inoculation and P either alone or in combination consistently increased cowpea grain yield across locations with yields ranging from 1097 kg ha-1 for the non-inoculated control to 1674 kg ha-1 for the inoculant + P treatment. Grain protein concentration followed a similar trend as grain yield and ranged from 223 to 252 g kg-1 but a negative correlation between grain yield and protein concentration was observed. Inoculation increased net returns by $104–163 ha-1 over that for the control. The results demonstrate the potential of improving cowpea grain yield, quality and profitability using inoculant, although the cost-benefit for using P at the current fertilizer price is not attractive except when applied together with inoculant at low P site.

Pathways to Improve Energy Efficiency and Minimize Environmental Footprints of GHG Emission of Energy Inputs Used in Cowpea Production in Niger State of Nigeria

“…In the literature review, studies which applied DEA to investigate GHG emission reduction in agricultural units in different countries on crop production and animal husbandry are few, and examples of such studies are Komleh et al [12], Komleh et al [13], Khoshnevisan et al [5], Khoshnevisan et al [6], Soni et al [19], Pelesaraei et al [9], Kordkheili et al [14], Sadiq et al [16], Sadiq et al [15], Sadiq et al [17], Onuk et al [11], Singh and Mukhi [18], Carvalho et al [7] and Kyei et al [20].…”

“…The performance assessment may be carried out by comparing a particular system with key competitors having best performance within the same group or another group performing similar functions, a process called benchmarking [4] [7] [18] and [20]. …”

Comparative effects of three levels of insect infestation on selected properties of five Nigerian cowpea (<i>Vigna unguiculasta (L.</i>) walp) varieties

“…It is the most important grain legume crop in Sub-Saharan Africa according to CGIAR (2017) and a major staple and source of inexpensive protein and other vital dietary components such as dietary fiber, calories, minerals, B-vitamins and essential fatty acids, especially among West Africans (National Research Council, 2006;Abudulai et al, 2016;CGIAR, 2017;Kyei-Boahen et al, 2017;Singh and Mukhi, 2017). Annually, about 12-15 million hectares of land is cultivated with cowpea worldwide with the Sub Saharan Africa accounting for the bulk of the total area of production (about 12 million hectares) and Nigeria responsible for about 1/3 rd (4-5 million hectares) of total world production area.…”

Phenotypic and serological evaluation of cowpea (Vigna unguiculata L.Walp) genotypes for resistance to viral infection under field conditions

“…Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License sub-Saharan Africa (SSA), especially in the dry savanna regions of West Africa (Asare et al, 2010;Dugje et al, 2009).The seeds are a major source of plant proteins and vitamins for man, feed for animals, and also a source of cash income. Cowpea leaves and green pods are consumed as vegetable and the dried grain is used in many different food preparations (Dugje et al, 2009;Kyei-Boahen et al, 2017).…”

“…Cowpea is an essential component of the cropping systems because it fixes atmospheric nitrogen and contributes to soil fertility improvement particularly in smallholder farming systems where little or no fertilizer is used (Kyei-Boahen et al, 2017). The crop is drought tolerant and adapted to stressful environments Ddamulira et al, 2015) such as the prevailing conditions of the dry savannah regions in Ghana.…”