COWPEA

Background: Cowpea (Vigna unguiculata (L.) Walp) is a vital legume crop in arid and semi-arid regions, valued for its high protein content and adaptability. However, soil salinity is a major environmental constraint that severely limits its early establishment, growth, and overall yield.Objective: This study evaluated the effects of varying levels of salt stress on the germination and early seedling growth of cowpea to determine its tolerance thresholds during the critical initial growth phase.Methodology: A controlled laboratory experiment was conducted using a completely randomized design (CRD) with three replications. Cowpea seeds were subjected to different concentrations of sodium chloride ($\text{NaCl}$) solutions, typically ranging from a control ($0\text{ mM}$ or $0\text{ dS m}^{-1}$) to severe salinity levels ($50\text{ mM}$, $100\text{ mM}$, $150\text{ mM}$, and $200\text{ mM}$). Germination parameters, including germination percentage (GP), germination velocity index (GVI), mean germination time (MGT), and early seedling growth traits (radicle and plumule lengths, fresh and dry biomass), were measured over a standard period of 7 to 10 days.Results: The results revealed that salt stress significantly ($P \le 0.05$) inhibited all measured parameters.Germination Rate: High salinity levels ($\ge 150\text{ mM}$) caused a drastic reduction in germination percentage and delayed the onset of germination, as evidenced by a significant increase in MGT.Seedling Vigour: Radicle and plumule lengths were highly sensitive to salinity, showing a progressive decline with increasing $\text{NaCl}$ concentrations. This suppression of early seedling growth is primarily attributed to osmotic stress and the toxic accumulation of $\text{Na}^+$ and $\text{Cl}^-$ ions, which restrict water uptake and disrupt metabolic processes.Conclusion: While cowpea exhibits moderate tolerance to low salinity levels ($\le 50\text{ mM}$), high salt concentrations severely hinder seed germination and early seedling establishment. These findings underscore the importance of screening for salt-tolerant cowpea genotypes and implementing strategic soil management practices in salinity-prone agricultural zones.

This study examines the impact of mulching on the MORPHOLOGY OF BBT BROWN VARIETY OF COWPEA (Vigna unguiculata (L.) Walp.) it was conducted in the university of Benin's Department of Plant Biology and Biotechnology botanic garden, the experiment aim to expose the impact of various mulched types on the cowpea. This research investigated the morphological responses of cowpea to eight distinct soil covers (mulch) comprising four inorganic mulch (Polythene Back(PO), Polythene White (PW), Polythene Transparent (PT),Polythene Blue (PB)) and five organic residual (Sawdust, Banana Leaves, Bamboo Leaves, Spent Substrate), against a non-mulched control. The primary objectives were to delineate the influence of each material on stand establishment, vegetative morphology, resource partitioning via the Root Mass Ratio (RMR), and the resulting economic yield components. The experiment evaluated critical parameters across the growth cycle, including Emergence Percentage, Shoot weight, leaf weight, Avg no of leaves, root collar Root Nodules count, RMR(Root Mass Ratio), and key yield components (Avg No of Pods, Avg No of Seeds/Pod, and Avg Pod Length, Avg pendicule length). The analysis revealed significant variation in morphology parameters and impact, it reveals that polythene Black (PO) treatment established itself as the leading practice for highest mean numbers of pods, this findings translated to an increase in pod output compared to the control(non- mulched).The outcome of the analysis also show that inorganic polythene white mulch influenced the cowpea plant as observed in the yield quality metrics having recorded the highest no of pods per seed and the longest Avg pod length, leading to a notable increase during harvest as compared to the control. It also showed that a certain mulch type (OS) influenced the cowpea plant to adopt a root prioritizing strategy giving that it recorded the highest no of nodules. This findings definitively confirms that mulching is essential for optimizing cowpea productivity, but the choice of material must align with the specific productions goals (Either for commercial yield maximization or it utility for long term soil biological sustainability).