Abstract:
Vitamin C is an important micronutrient because of its antioxidant and health promoting properties.
With the introduction and commercialization of improved African indigenous plants, few studies have
examined the impact of leaf age or the nutrient status of the plants by fertilizer. This study sought to
determine amounts of vitamin C using redox titration in mature and immature leaves of spider plant
(Cleome gynandra) and black nightshade (Solanum ssp) grown in fields and subjected to various
sources of fertilizers which were chicken manure to provide an organic source, Mavuno fertilizer to
provide a conventional synthetic source and no fertilizer to serve as a control. Chicken manure led to
the highest (167 mg/100 g) vitamin C content which was however not statistically significant from
Mavuno fertilizer (150 mg/100 g) at P≤ 0.05 in the nightshade variety. The highest vitamin C with no
fertilizer application was 105/100 g and 79 mg/100 g in SS-49 and UG-SF varieties respectively.
Moreover, vitamin C content was highest in mature leaves than in immature ones whatever the kind of
fertilization treatment applied. By recognizing the impact of leaf age and importance of providing
adequate fertilization, farmers can produce higher yielding and more nutritious leafy greens.
