Identifying and managing plant health risks for key African crops: yams and cocoyams

Publication date: 07/02/2019
Extent: 16 pages

Contributions by: Babatima Djana Mignouna, IITA, Benin; P. Lava Kumar, IITA, Nigeria; Danny Coyne, IITA, Kenya; and Ranajit Bandyopadhyay, Alejandro Ortega-Beltran, Ranjana Bhattacharjee and David De Koeyer, IITA, Nigeria

Chapter synopsis: A large proportion of the world’s yams, which are mostly indigenous to Africa, and the exotic taro and cocoyam are grown in West and Central Africa by resource-poor farmers. Surveys demonstrate recycling and build-up of pathogens and nematodes from one generation to the next because of their vegetative mode of propagation. Minisett techniques, organ culture, vine cuttings and so on, and the use of botanic seeds can alleviate these problems. The main pests are two types of nematodes, among which root-knot nematodes have increased recently, yam beetles, fungi and viruses, but many fungal pathosystems remain unexplored. Marker-assisted resistance breeding, particularly against yam mosaic virus, is using next-generation sequencing techniques and robust phenotypic screening. Virus-free material can be obtained by hot water treatment of seed tubers. There is a huge prospect of using genomics and transgenic approaches to accelerate the rate of improvement without affecting production and productivity.

DOI: 10.19103/AS.2018.0043.09