African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12486

Full Length Research Paper

Ascorbic acid content in leaves of Nightshade (Solanum spp.) and spider plant (Cleome gynandra) varieties grown under different fertilizer regimes in Western Kenya

Emmanuel Ayua
  • Emmanuel Ayua
  • Department of Family and Consumer Sciences, University of Eldoret Box 1125-30100, Eldoret, Kenya.
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Violet Mugalavai
  • Violet Mugalavai
  • Department of Family and Consumer Sciences, University of Eldoret Box 1125-30100, Eldoret, Kenya.
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James Simon
  • James Simon
  • New Use Agriculture and Natural Plant Products Unit, Department of Plant Biology and Plant Pathology, Rutgers University, New Brunswick, NJ, USA.
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Stephen Weller
  • Stephen Weller
  • Horticulture Department, Purdue University, West Lafayette, IN, USA.
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Pamela Obura
  • Pamela Obura
  • Horticulture Department, Purdue University, West Lafayette, IN, USA.
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Naman Nyabinda
  • Naman Nyabinda
  • Academic Model Providing Access to Healthcare (AMPATH), P.O Box 4606, Eldoret, Kenya.
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  •  Received: 21 August 2015
  •  Accepted: 25 January 2016
  •  Published: 17 February 2016

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.

Key words: Leaf age, vitamin C, fertilizers, plant nutrition, spider plant, nightshade