Fast track participatory approach to release of elite cassava genotypes for various uses in Nigeria’s cassava economy

Abstract

The aim of the Integrated Cassava Project (ICP) of the International Institute of Tropical Agriculture was to pre-emptively manage the cassava mosaic disease (CMD) to avert an imminent and increasing possible threat of the Ugandan strain of the CMD virus of the pathogen from doing damage to the Nigerian cassava economy. The strategy was to engage in activities that would lead to cultivarsubstitution by replacing the susceptible varieties on farmers' fields with superior genotypes that are not only CMD resistant or tolerant but also high yielding with good dry matter content. A fast track participatory selection approach was used in 2 years to release nine new lines in Nigeria. It was intensive and several lessons were learnt. The varieties released after 2 years were TMS 98/0510, TMS 98/0581, TMS 97/2205, TMS 98/0505, TME 419, TMS 92/0326, TMS 96/1632, TMS 98/0002, and TMS 92/0057.

Cassava: An appraisal of its phytochemistry and its biotechnological prospects

“…The facility with which its genomes recombine to produce novel variants with altered virulence is a challenge (Bull et al, 2006); in particular its more virulent Ugandan variant form (Legg et al, 2006) and especially the recombined viral strain EACMV-Ug2 (Dixon et al, 2008). Recently, cassava brown streak virus (CBSV), which, like ACMV, is also transmitted by white fly, has been recognised as an emerging threat to cassava production (Maruthi et al, 2005).…”

Introgression of whitefly (Aleurotrachelus socialis) resistance gene from F1 inter-specific hybrids into commercial cassava

“…Whitefly-borne geminiviruses (CMG) occur in all main cassava-growing areas of Africa where it has been ranked as the most important vector-borne disease of any food crop (Geddes 1990), and has become the object of extensive research (Thresh et al 1994;Bellotti and Arias 2001;Fregene et al 2000;Akano et al 2002;Legg and Fauquet 2004;Tomkins et al 2004;Ogbe et al 2006;Okogbenin et al 2007;Dixon et al 2008). The discovery and use of new resistance genes from wild relatives have steadily increased in different crops (Carabali et al 2010).…”

“…Yield losses resulting from Aleurotrachelus socialis and Aleurotrachelus aepim activity (Vargas and Bellotti 1981;Farias 1994;Bellotti et al 1999;Carabali et al 2010) are common in Colombia and Brazil. However, African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV) and the new Ugandan virus strain of EACMV (EACMV-Ug 2 ) is a major growing threat (Ogbe et al 2006;Dixon et al 2008).…”

Introductory Chapter: Cassava as a Staple Food

“…Adoption of new varieties of cassava has been strong in Thailand, Vietnam and Nigeria [25][26][27]. Given the current practice of minimal use of inputs, great scope also exists for closing the large yield gap of cassava production through beter agronomy [24].…”