F. N. Egbenoma

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.

Soybean (Glycine max [L.] Merr.) Is one of the most essential oil plant that is largely grown globally. Its domestic and industrial use hasbrought about increase in the economy of many countries. About 64 % of the world's supply of oil seed meal comes from soy, which also serves as the primary source of oil and contributes to about 28 % of output as a whole. Soybean which is a legume crop serves as food to humans and animals and other beneficial purpose. 10 different accessions of soybean were studied to check if there will be significant change in their morphological and physiological characteristics. The set of descriptors for the present morphological characterization of Soybean was produced using the Sphenostylis stenocarpa (Hochst ex. A. Rich.) Harms descriptor and the seed length, seed width and seed thickness of 10 seeds from each accession number were determined using a venire caliper. Accession number TGM-942 had the least length, 0.47 cm while Accession number TGM-944 had the highest length, 0.58 cm. Accession number TGM-540 seed weighed 1.45 g, which was the highest see weight. Their testa basal colorranged from black, reddish brown, light brown, black to purple.

Ferruginous soils present challenges for plant growth due to their elevated iron levels, which can cause iron toxicity and negatively impact crop productivity. Copper nanoparticles demonstrate potential in mitigating iron toxicity in plants. This research studied maize plants polluted with different copper nanoparticle concentrations in ferruginous soils with elevated iron. The aim was to ascertain maize tolerance to various iron stress levels and its resultant yield. The results indicated improved maize growth with copper nanoparticles, significantly at 35% and 100% concentration in the early and late development phases. This infers a dose- dependent relationship between nanoparticle concentration and maize growth, with higher concentrations conveying increased maize sensitivity to excessive iron levels. The dynamic response of maize to nanoparticles over time emphasizes the need for exposure duration. In week 2, plants polluted with a 35% Cu nanoparticle concentration in soils alleviated at 4 ESV portrayed smaller leaf areas in contrast to those in 2.5 ESV soils. This infers that higher contamination may hamper the nanoparticles' positive leaf area effects. The complex impact of copper nanoparticles on maize morphology was influenced by a combination of factors including concentration, soil contamination, and specific parameters. Plant height, leaf length, leaf width, leaf area, and sheath length were modified by treatment, while blocks substantially affected plant height, leaf length, and sheath length. Copper nanoparticles demonstrate the potential to improve maize resilience in ferruginous soils, presenting a viable sustainable agriculture solutions in iron-rich environments.

Ferruginous soils pose challenges for plant growth as their high iron content can lead to iron toxicity and reduced crop yields. Copper nanoparticles show promise in alleviating iron toxicity in plants. This project assessed maize plants treated with varying copper nanoparticle concentrations in ferruginous soils with elevated iron. The goal was to evaluate maize tolerance to different iron stress levels and resultant yield. The results revealed enhanced maize growth with copper nanoparticles, especially at 35% and 100% concentrations, in both initial and subsequent growth stages. This indicates a dose-dependent relationship between nanoparticle concentration and maize growth, with higher concentrations conferring increased maize survivability against iron toxicity. Temporal dynamics emerged in the maize response to nanoparticles, underscoring the need to consider exposure duration in applications. During week 2, plants treated with a 35% Cu nanoparticle concentration in soils contaminated at 4 ESV displayed smaller leaf areas than those in 2.5 ESV soils. This suggests higher contamination may hinder the nanoparticles' positive leaf area effects. Overall, the intricate effects of copper nanoparticles on maize morphological characteristics depended on concentration, soil contamination, and specific parameters. Plant height, leaf length/width/area, and sheath length were influenced by treatment, while blocks significantly impacted plant height, leaf length, and sheath length. Copper nanoparticles show the potential to enhance maize survivability in ferruginous soils, offering a promising sustainable agriculture avenue in iron-rich environments.