Screening of Selected Improved Cassava Varieties for Bacterial Blight and Varietal Performance under Natural Environment in Ibadan, South-Western Nigeria

Abstract

Cassava production is bedeviled by a plethora of biotic constraints among which Bacterial Blight is of most economic important in most cassava growing regions of Sub-Saharan Africa and Asia. Deployment of improved resistant varieties by various research institutes have thus far brought the disease under control, but continuous monitoring remains imperative to forestall further outbreak. For this reason, field experiment was performed to specifically screen six improved cassava varieties for CBB incidence and severity under natural environment at the botany research farm, University of Ibadan, Ibadan, Nigeria. The experimental field was laid out in a Randomized Complete Block Design with four replications each. The plot size was 20m x 41m comprising ridges each measuring 10m with 1m interval. Parameters assessed were disease incidence, disease severity scores and varietal performance for each genotype. Results from statistical analysis of SAS 9.3 (SAS, 2010) revealed that all the varieties expressed moderate to resistant (2.25-1.75) reaction to CBB severity in the field. Pearson correlation coefficient also indicated a significant negative correlation between root yield and root weight. From the foregoing, the result implicitly showed that farmers could reduce the high incidence of CBB in their farms and increase their yield by replacing the local lines with the improved varieties. Government should also organize programs (such as seminars and talk shows) addressing cassava diseases to further enlighten farmers on the importance of adopting improved cassava cultivation