Evaluation of Cassava Genotypes for Resistance to Cassava Mosaic Disease and Agronomic Traits

Abstract

Sixteen cassava genotypes comprising introductions, local landraces and improved genotypes were evaluated for two seasons in Mansa, Zambia, for their reaction to cassava mosaic disease (CMD). The study was conducted in 2009/10 and 2010/11 seasons to evaluate the reaction of cassava cultivars to CMD and agronomic traits. Cassava mosaic disease severity and leaf retention were scored at 6 months after planting (MAP) and data on yield and yield components were recorded at harvest (7 MAP). Significant genotype x season interaction for CMD, harvest index, fresh root yield, biomass, plant height, root size and leaf retention was recorded. Bangweulu, Kalaba, Chikula, Mwakamoya and Chila-7 were the most susceptible genotypes over the two seasons. Mweru, Kampolombo, TMS190, TMS3001, Tanganyika and Nalumino had low severity scores. Harvest index ranged from 0.36 (Mwakamoya) to 0.55 (Chila-7) for the combined seasons. Chila-7 had the highest fresh root yield with a mean of 0.87 kg plant - 1 for the combined seasons. The re sistant genotypes might be used to improve the CMD resistance of local cultivars through hybridisa tion.