Author(s)

Bernadetta Kimata¹, Emily Masinde², Festo Masisila¹, Rahim Menya¹, Dwasi Matondo¹, Midatharahally N. Maruthi³, Geoffrey Mkamilo^4*

¹Tanzania Agricultural Research Institute (TARI)-Naliendele, Mtwara, Tanzania.
²Department of Crops Horticulture and Soils, Egerton University, Njoro, Kenya.
³Natural Resources Institute, University of Greenwich, London, UK.
⁴Tanzania Agricultural Research Institute (TARI)-Makutupora, Dodoma, Tanzania.

Cassava productivity is hampered by pests and diseases including cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). The main objective of this study was to identify stable superior genotypes that combine disease resistance and high yield. Sixteen cassava genotypes were planted in a randomized complete block design with three replications for six planting seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (P < 0.001) effects of genotype, environment, and genotype-by-environment (G^*E) interactions were observed for all traits studied. Percent sum of squares (SS) due to environment (12.66% - 85.23%) was the highest followed by G^*E (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) was highest followed by G^*E (26.14% - 35.91%) for CBSD foliar and root symptoms indicating that the environment and G^*E greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.

Cassava Brown Streak Disease, Cassava Mosaic Disease, Disease Resistance, Genotype*Environment Interaction, High Yield

Kimata, B. , Masinde, E. , Masisila, F. , Menya, R. , Matondo, D. , Maruthi, M. and Mkamilo, G. (2021) Adaptability and Phenotypic Stability of Resistance to Two Viral Diseases and Yield Traits in Cassava. American Journal of Plant Sciences, 12, 679-705. doi: 10.4236/ajps.2021.124046.