Publications des agents du Cirad


Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review

Ratnadass A., Fernandes P., Avelino J., Habib R.. 2012. Agronomy for Sustainable Development, 32 (1) : p. 273-303.

Farmers are facing serious plant protection issues and phytosanitary risks, in particular in the tropics. Such issues are food insecurity, lower income in traditional lowinput agroecosystems, adverse effects of pesticide use on human health and on the environment in intensive systems and export restrictions due to strict regulations on quarantine pests and limits on pesticide residues. To provide more and better food to populations in both the southern and northern hemispheres in a sustainable manner, there is a need for a drastic reduction in pesticide use while keeping crop pest and disease damage under control. This can be achieved by breaking with industrial agriculture and using an agroecological approach, whose main pillar is the conservation or introduction of plant diversity in agroecosystems. Earlier literature suggest that increasing vegetational biodiversity in agroecosystems can reduce the impact of pests and diseases by the following mechanisms: (1) resource dilution and stimulo-deterrent diversion, (2) disruption of the spatial cycle, (3) disruption of the temporal cycle, (4) allelopathy effects, (5) general and specific soil suppressiveness, (6) crop physiological resistance, (7) conservation of natural enemies and facilitation of their action against aerial pests and (8) direct and indirect architectural/ physical effects. Here we review the reported examples of such effects on a broad range of pathogens and pests, e.g. insects, mites, myriapods, nematodes, parasitic weeds, fungi, bacteria and viruses across different cropping systems. Our review confirms that it is not necessarily true that vegetational diversification reduces the incidence of pests and diseases. The ability of some pests and pathogens to use a wide range of plants as alternative hosts/reservoirs is the main limitation to the suppressive role of this strategy, but all other pathways identified for the control of pests and disease based on plant species diversity (PSD) also have certain limitations. Improving our understanding of the mechanisms involved should enable us to explain how, where and when exceptions to the above principle are likely to occur, with a view to developing sustainable agroecosystems based on enhanced ecological processes of pest and disease control by optimized vegetational diversification. (Résumé d'auteur)

Mots-clés : Étude de cas; Écologie; agent de lutte biologique; hôte; interactions biologiques; relation hôte pathogène; relation hôte parasite; développement durable; plante de culture; horticulture; agroforesterie; agroécologie; agriculture alternative; agrobiodiversité; agroécosystème; ravageur des plantes; maladie des plantes; gestion intégrée des ravageurs; méthode de lutte; protection des plantes; monde; agriculture de conservation

Thématique : Maladies des plantes; Ravageurs des plantes; Ecologie végétale; Ecologie animale; Conservation de la nature et ressources foncières; Systèmes et modes de culture

Documents associés

Article de revue

Agents Cirad, auteurs de cette publication :