African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6578

Review

Allelopathic weed suppression in agroecosystems: A review of theories and practices

Michael Ignatius Ferreira
  • Michael Ignatius Ferreira
  • Research and Technology Development Services, Western Cape Department of Agriculture, Private Bag X1, Elsenburg, 7607, South Africa.
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Carl Friedrich Reinhardt
  • Carl Friedrich Reinhardt
  • Department of Plant Production and Soil Science, University of Pretoria, Pretoria, South Africa
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  •  Received: 27 October 2015
  •  Accepted: 27 January 2016
  •  Published: 11 February 2016

Abstract

Weeds cause great problems to humankind by interfering in food production, health, economic stability, and welfare. The overuse of synthetic herbicides for weed control eventually leads to the evolution of herbicide resistant weeds, which also resulted in growing public concern over their impacts upon human health. The intensification of arable farming has also had a simultaneous impact on the environment. This intensification of the landscape may disrupt natural processes, such as resistance to plant invasion. Therefore, the aim of this review is to address these production constraints by suggesting applications of allelopathy via smother cropping, because this may ease the incidence of herbicide resistance and in the process promote cultivated plant diversity and thereby maintaining healthy agroecosystems. Weed resistance to herbicides presents one of the greatest current economic challenges to agriculture. System-oriented approaches to weed management that make better use of alternative weed management tactics need to be developed. Plant roots exude a wide variety of metabolites, some of which may act as allelochemicals and mediate interactions between plants and other organisms. These metabolites are in essence chemicals from nature which may be exploited for weed management as an alternative weed control option. Smother crops, as well as its mulches, have been shown to release allelochemicals, which were inhibitory to weeds. The principal goal of smother crops is to control weeds by replacing an unmanageable weed population with a manageable smother crop. More data from the grey area where agriculture and ecology overlap will enable the greater use of ecosystem services for crop protection in agricultural production and consequently reduce the incidence of resistance to agricultural chemicals.

 

Key words: Agroecosystems, allelopathy, cultivated ecosystems, herbicide resistance, smother cropping, mulching.