African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6668

Full Length Research Paper

Thorn apple (Datura stramonium L.) allelopathy on cowpeas (Vigna unguiculata L.) and wheat (Triticum aestivum L.) in Zimbabwe

Nyasha Sakadzo
  • Nyasha Sakadzo
  • Department of Horticulture, Midlands State University, P Bag 9055, Gweru, Zimbabwe.
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Pahla Innocent
  • Pahla Innocent
  • Department of Horticulture, Midlands State University, P Bag 9055, Gweru, Zimbabwe.
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Muzemu Simbarashe
  • Muzemu Simbarashe
  • Department of Horticulture, Midlands State University, P Bag 9055, Gweru, Zimbabwe.
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Mandumbu Ronald
  • Mandumbu Ronald
  • Crop Science Department, Bindura University of Science Education, P. Bag 1020, Bindura, Zimbabwe.
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Makaza Kasirayi
  • Makaza Kasirayi
  • Department of Soil and Plant Sciences, School of Agriculture and Natural Sciences, Great Zimbabwe University, P. O. Box 1235 Masvingo, Zimbabwe.
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  •  Received: 05 May 2018
  •  Accepted: 05 June 2018
  •  Published: 19 July 2018

Abstract

Datura stramonium extracts have allelopathic properties. The study was conducted to investigate the allelopathic effects of D. stramonium weed on seed germination, early seedling growth and dry biomass of crop plants (Triticum aestivum and Vigna unguiculata). Laboratory and greenhouse trials were arranged as completely randomised design and the field pot experiment was arranged as a randomised complete block design. Aqueous leaf extracts of D. stramonium at 2, 4, 6 and 8% concentrations were applied to determine their effects on seed germination, early seedling growth of crops under laboratory, field and greenhouse conditions. Distilled water (0%) acted as a control.  Results from the study indicated that germination, shoot length and dry weight significantly decreased proportionally (p<0.001) as the concentration increased from 2 to 8%. The results showed that D. stramonium has allelopathic effects on wheat and cowpeas, hence cannot be used as a bio herbicide to control Tagetes minuta and Amaranthus hybridus on the selected crops since it is non selective to the crops studied. There is therefore need for further research on screening of arable crops against the allelopathic effects of D. stramonium. This will help to identify arable crops which are not negatively affected by allelochemicals from D. stramonium weed so that it can be used as a selective bio herbicide against other weeds.

Key words: Allelopathy, aqueous leaf extract, Datura stramonium, Triticum aestivum, Vigna unguiculata.