IITA IPM project 24: Indigenous arbuscular mycorrhizal fungi: examination of their potential as an environmentally sensitive management option for yam nematodes in West Africa

Duration: 3 years (2004 to 2006)

Purpose: To identify strategies to reduce the impact of nematode pests and improve the quality of yam through the novel use of an indigenous fungal biocontrol agent.

Background/description: In the “yam belt” region of West Africa, yam (Dioscorea spp.) supplies one-third of the calories required to feed millions of people, and holds an important place in the socio-cultural life. . Major threats to yam production in Benin and Togo are “dry rot disease” caused by the migratory endoparasitic nematode, Scutellonema bradys, and “gales” caused by the sedentary endoparasitic nematode Meloidogyne spp. Both nematodes attack roots and growing tubers of yam plants and cause severe yield losses both pre- and post-harvest. Main nematode control methods, such as through the application of chemicals and identification of resistant varieties are not in use in this region because of elevated costs of and human/environmental risks associated with chemicals. Useful sources of resistance have yet to be identified. As yam nematodes are propagated along with infected seed material, and arbuscular mycorrhizal fungi (AMF) have shown suppressive effect on nematode infestations, it is predicted that AMF could provide a sustainable method of nematode management in yam systems. Our objective is to collect and isolate AMF from the yam ecosystems of this region, and screen the indigenous AMF strains for their compatibility to improve vigour and growth of yam and for their potential in controlling yam nematodes.

Agroecozone(s) and location(s): Humid forest and savannas in Benin, Togo and Nigeria

Expected outputs: a) Map of the occurrence and diversity of AMF in agro- and natural ecosystems of the “yam belt” region in Togo and Benin; b) Knowledge transfer (AMF identification, propagation and application) from the University of Basel to IITA Benin; c) Establishment of a West African AMF gene bank at IITA Benin in Cotonou/Calavi; d) Screening of AMF strains to improve yam growth and suppression of S. bradys and Meloidogyne incognita; e) First recommendations for the use of AMF in West African yam production.

Potential impact and beneficiaries: To be stated

Partners: a) NARs Togo; b) Institute of Botany, University of Basel, Switzerland.

Development investor(s): Swiss Centre for Agriculture (ZIL)

IITA contact person(s)/principal investigator(s): Danny Coyne D.Coyne@cgiar.org website http://www.iita.org