Mapping the drivers of parasitic weed abundance at a national scale: a new approach applied to #Striga asiatica" in the mid-west of Madagascar

Scott Donald, Scholes Julie D., Randrianjafizanaka Meva Tahiry, Randriamampianina Jean Augustin, Autfray Patrice, Freckleton Robert P.. 2020. Mapping the drivers of parasitic weed abundance at a national scale: a new approach applied to #Striga asiatica" in the mid-west of Madagascar. Weed Research, 60 (5) : pp. 323-333.

Journal article ; Article de recherche ; Article de revue à facteur d'impact
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Abstract : The parasitic weed genus Striga causes huge losses to crop production in sub-Saharan Africa, estimated to be in excess of $7 billion per year. There is a paucity of reliable distribution data for Striga; however, such data are urgently needed to understand current drivers, better target control efforts, as well as to predict future risks. To address this, we developed a methodology to enable rapid, large-scale monitoring of Striga populations. We used this approach to uncover the factors that currently drive the abundance and distribution of Striga asiatica in Madagascar. Two long-distance transects were established across the middle-west region of Madagascar in which S. asiatica abundance in fields adjacent to the road was estimated. Management, crop structure and soil data were also collected. Analysis of the data suggests that crop variety, companion crop and previous crop were correlated with Striga density. A positive relationship between within-field Striga density and the density of the nearest neighbouring fields indicates that spatial configuration and connectivity of suitable habitats is also important in determining Striga spread. Our results demonstrate that we are able to capture distribution and management data for Striga density at a landscape scale and use this to understand the ecological and agronomic drivers of abundance. The importance of crop varieties and cropping patterns is significant, as these are key socio-economic elements of Malagasy cropping practices. Therefore, they have the potential to be promoted as readily available control options, rather than novel technologies requiring introduction.

Mots-clés Agrovoc : Striga asiatica, Distribution des populations, Plante parasite, Mauvaise herbe, surveillance

Mots-clés géographiques Agrovoc : Madagascar

Mots-clés libres : Legumes, Madagascar, NERICA rice varieties, Parasitic weeds, Striga asiatica, Weed management, Weed survey

Classification Agris : H60 - Weeds and weed control

Champ stratégique Cirad : CTS 4 (2019-) - Santé des plantes, des animaux et des écosystèmes

Auteurs et affiliations

  • Scott Donald, University of Sheffield (GBR) - auteur correspondant
  • Scholes Julie D., University of Sheffield (GBR)
  • Randrianjafizanaka Meva Tahiry, Université d'Antananarivo (MDG)
  • Randriamampianina Jean Augustin, FOFIFA (MDG)
  • Autfray Patrice, CIRAD-PERSYST-UPR AIDA (FRA)
  • Freckleton Robert P., University of Sheffield (GBR)

Source : Cirad-Agritrop (

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