Conversion of cassava (Manihot esculenta) roots to processed products such as gari and fufu before consumption is a common practice worldwide by cassava end-user for detoxification, prolonged shelf life or profitability. Fresh root and processed product yield are supposed to be equivalent for each genotype, however, that is not the case. Developing genotypes with high product conversion rate is an important breeding goal in cassava as it drives the adoption rates of new varieties. The objective of this study was to quantify the contribution of genetic and genotype-by-environment interaction (GEI) patterns on cassava root conversion rate to gari and fufu. Sixty-seven advanced breeding genotypes from the International Institute of Tropical Agriculture (IITA) were evaluated across eight environments in Nigeria. Root conversion rate means across trials ranges from 14.72 to 22.76% for gari% and 16.96–24.24% for fufu%. Heritability estimates range from 0.17 to 0.74 for trial bases and 0.71 overall environment for gari% and 0.03–0.65 for trial bases and 0.72 overall environment for fufu% which implies that genetic improvement can be made on these traits. Root conversion rate for both gari and fufu% showed a negative but insignificant correlation with fresh root yield and significant positive correlation to Dry Matter content. For all fitted models, environment and interaction had explained more of the phenotypic variation observed among genotypes for both product conversion rates showing the presence of a strong GEI. Wrickle ecovalence (Wi) stability analysis and Geometric Adaptability index (GAI) identified G40 (TMS14F1285P0006) as part of top 5 genotypes for gari% but no overlapping genotype was identified by both stability analysis for fufu%. This genotypic performance across environments suggests that it is possible to have genotype with dual-purpose for high gari and fufu conversion rate.

BACKGROUNDGari is an important (especially in Nigeria) West African food product made from cassava. It is an affordable, precooked, dry, easy to prepare and store food product. Eba is a stiff dough produced by reconstituting gari in hot water. Gari and eba quality is an important driver of varietal acceptance by farmers, processors, and consumers.RESULTSThe current study characterized the genetic variability, heritability and correlations among quality‐related traits of fresh roots, gari and eba. Thirty‐three diverse genotypes, including landraces, released and advanced breeding genotypes were used in this study. In total, 40 traits categorized into: fresh root quality, colour, functional and texture properties trait groups were assessed. We observed broad phenotypic variability among the genotypes used in this study. Dry matter content (DM) had a positive (p < 0.05) correlation with gari%, bulk density and a negative correlation with eba hardness and gumminess. Broad‐sense heritability across all environments varied considerably among the different trait groups: 62% to 79% for fresh root quality, 0 to 96% for colour, 0 to 79% for functional and 0 to 57% for texture properties.CONCLUSIONSThe stable broad‐sense heritability found for gari%, gari and eba colour, bulk density, swelling index and ITPA‐hardness coupled with sufficient variability in the population indicates good potential for genetic improvement of these traits through recurrent selection. Also, it is possible to genetically improve gari%, bulk density and swelling power by simultaneously improving dry matter content of fresh roots.This article is protected by copyright. All rights reserved.