Journal of
Agricultural Biotechnology and Sustainable Development

  • Abbreviation: J. Agric. Biotech. Sustain. Dev.
  • Language: English
  • ISSN: 2141-2340
  • DOI: 10.5897/JABSD
  • Start Year: 2009
  • Published Articles: 138

Full Length Research Paper

Analysis of micronutrients variations among sweet potato (Ipomoea batatas [L.] Lam) genotypes in Malawi

Felistus Chipungu
  • Felistus Chipungu
  • Bvumbwe Agricultural Research Station, P. O. Box 5748, Limbe, Malawi.
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Wisdom Changadeya
  • Wisdom Changadeya
  • Molecular Biology and Ecology Research Unit (MBERU) DNA Laboratory, Department of Biological Sciences, Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi.
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Aggrey Ambali
  • Aggrey Ambali
  • NEPAD African Biosciences Initiative, Policy Alignment and Programme Development Directorate, NEPAD Agency, C/O CSIR Building 10F, Meiring Naude Road, Brummeria, Pretoria, Republic of South Africa, 0001, South Africa.
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John Saka
  • John Saka
  • University of Malawi, University Office, P. O. Box 278, Zomba, Malawi.
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Nzola Mahungu
  • Nzola Mahungu
  • The International Institute of Tropical Agriculture (IITA), Central Africa Hub, 4163, Avenue Haut-Congo, Commune de la Gombe, Kinshasa, Democratic Republic of Congo (DRC), Congo.
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Jonathan Mkumbira
  • Jonathan Mkumbira
  • Tea Research Foundation of Central Africa, P. O. Box 51, Mulanje, Malawi.
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  •  Received: 09 June 2017
  •  Accepted: 11 August 2017
  •  Published: 30 September 2017


Sweet potato (Ipomoea batatas [L.] Lam) is an important root crop in Malawi and Sub-Saharan Africa where micronutrient deficiency is an eminent health problem. Using 15 sweet potato genotypes grown in a randomized complete block design at Bvumbwe Research Station, a study was undertaken to determine the extent of variability of selected micronutrients in the genotypes as influenced by storage root age and peeling. Analysis of variance (ANOVA) showed significant (p≤ 0.01) variability among genotypes for dry mater, β-carotene, ascorbic acid levels and reduction of β-carotene due to peeling across all ages. Significant (p ≤ 0.05) variations in zinc, iron and copper were also observed among all genotypes. Peeling reduced β-carotene, ascorbic acid levels, iron, zinc and copper content while late harvesting resulted in low iron, zinc and copper. Therefore, 5 months after planting (MAP) and 4 MAP are recommended for high levels of β-carotene and ascorbic acid and iron, zinc and copper, respectively. Ten genotypes exhibited acceptable levels of dry mater of ≥30%. Zondeni (10.9 mg/100 g, WW) and Babache (23.84 mg/100 g, WW) had highest levels of β-carotene and ascorbic acid, respectively. Mzungu displayed the highest levels of Iron (0.67 mg/100 g, DW) and zinc (0.63 mg/100 g, DW) while Yoyera (0.61 mg/100 g, DW) had the highest levels of copper. Variations of various traits entail potential to breed for higher levels of micronutrients.

Key words: Sweet potato, genotypes, β-carotene, ascorbic acid, iron, zinc, copper, peeling, storage root age.