Evaluation of selected cassava germplasm for tolerance to cassava bacterial blight disease in Kenya

  • E. Simiyu University of Nairobi
  • J. Cheboi University of Nairobi
  • D. Miano University of Nairobi
  • P. Kuria Kenya Agricultural and Livestock Research Organization- Biotechnology Research Center


Several biotic factors have constrained cassava production. Cassava bacterial blight (CBB) is one of the biotic factors affecting cassava production. It is of great economic importance in all the cassava cultivating regions of Africa, Latin America, and Asia. Mitigation measures of CBB include adoption and use of resistant varieties and breeding for resistance. One glasshouse and two field experiments were performed to identify the responses  of  the  selected  cassava  genotypes  to infection  by  CBB.  Fifteen Kenyan cassava  genotypes were artificially inoculated with CBB. At the same time, natural infectivity was carried out under field conditions at Kiboko and Kakamega. The experimental trials were laid out in Randomized Complete Block Design (RCBD) with three replications. Field experiments involved planting each cassava genotype cutting (30 cm) in plots of 1 x 10 m at a spacing of 1 m between plants. Plots were separated with an alleyway measuring 1.5 m between plots, whereas a glasshouse experiment was established in pots using 30cm cuttings. Data was collected at intervals of seven days post-inoculation for the glasshouse experiment and intervals  of  30  days  for  field  experiments  from  three months after planting. Statistical analysis revealed that two genotypes, Migyera and NASE 14, were reactant (mean  score  of  1.9),  three  genotypes  (Ebwanatereka 2,  Fumbachai,  and  MM97/0293)  expressed  moderate resistance (mean scores of 2.0, 2.1, 2.3, and 2.4) reactions to CBB severity in the glasshouse conditions. Moreover, at  the  Kakamega  experimental  site,  Ebwanatereka  2, Migyera, and NASE 14 were observed as reactant (mean score of 1.8, 1.9 and 1.9, respectively). However, there was no significant difference between genotypes for their response to CBB at the Kiboko experimental site. This study, therefore, provides baseline data that can be used to identify potential tolerant genotypes that can be used as candidate parents for Cassava breeding in Kenya.

How to Cite
Simiyu, E., Cheboi, J., Miano, D., & Kuria, P. (2022). Evaluation of selected cassava germplasm for tolerance to cassava bacterial blight disease in Kenya. East African Agricultural and Forestry Journal, 85(1-4), 7. Retrieved from https://www.kalro.org/www.eaafj.or.ke/index.php/path/article/view/511