African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6691

Full Length Research Paper

Variation in beta carotene and yield in sweetpotato (Ipomoea batatas (L.) Lam.) associated with ambient temperature and genotype

Brian SINGOGO
  • Brian SINGOGO
  • Palabana Dairy Training Institute, P. O. Box 50199, Lusaka, Zambia.
  • Google Scholar
Mebelo MATAA
  • Mebelo MATAA
  • Department of Plant Sciences, School of Agricultural Sciences, University of Zambia, P. O. Box 32379, Lusaka, Zambia.
  • Google Scholar
Kalaluka MUNYINDA
  • Kalaluka MUNYINDA
  • Department of Plant Sciences, School of Agricultural Sciences, University of Zambia, P. O. Box 32379, Lusaka, Zambia.
  • Google Scholar
Davies LUNGU
  • Davies LUNGU
  • Department of Plant Sciences, School of Agricultural Sciences, University of Zambia, P. O. Box 32379, Lusaka, Zambia.
  • Google Scholar
Emily MUELLER
  • Emily MUELLER
  • Formally with International Potato Center, Integrating Orange-fleshed Sweetpotato Project Zambia, Msekera Research Station, Chipata, Zambia.
  • Google Scholar


  •  Received: 23 April 2020
  •  Accepted: 15 December 2020
  •  Published: 31 March 2021

Abstract

This study was conducted to determine the relationship between ambient temperature during growing season on tuber β-carotene content and yield of four orange-fleshed sweetpotato varieties; Orange Chingovwa, Olympia, Kokota and Zambezi. A split plot experiment design with the environment (main plot) and variety (subplots). The environments were: High-temperature site (HTS) (average temperature of 38.5°C) and moderate temperature site 1 (MTS 1) and moderate temperature site 2 (MTS 2) (average temperature 32.2 and 31.2°C, respectively). Results suggested that assimilate partitioning between below ground components (tubers) and above ground components (leaves and vines) were inversely related and influenced by ambient temperature during development. Low temperatures favoured tuber formation. The HTS had lower yield (0.97 ton ha-1) compared to the two moderate temperature sites that had tuber yield between 11.96 and 9.41 ton ha-1. The HTS at 7.23 mg/100 g had lower β-carotene contents compared to the MTS sites (≈15.5 mg/100 g). Zambezi and Orange Chingovwa had higher β-carotene content at 21.21 mg/100 g and (18.85 mg/100 g). Kokota had the least β-carotene (3.28 mg/100 g Vine Yield (VY) was significantly different for sites. HTS had the highest VY and leaf area (23.6 t/ha) while the two MTS had low VY of 8.7 and 12.9 t/ha.

Key words: Partitioning, tuber, leaf area, vine, yield.