INCIDENCE OF CASSAVA MOSAIC DISEASE IN KEBBI STATE, NIGERIA

Abstract

Cassava mosaic disease (CMD) is one of the most important and biotic constraints affecting cassava limiting the production potential of the crop in Northern Nigeria. This study was carried out to evaluate the incidence, severity and infection type of the disease in Kebbi State, Nigeria. A total of thirty-three (33) fields were surveyed and, in each field, thirty plants were assessed along two diagonals and symptomatic and non-symptomatic leaf samples were collected from the fields surveyed for laboratory analysis. The results of the study revealed that CMD incidence was highest in Gwandu (89%) and lowest in Bunza (43%). The disease symptom severity was generally mild. It was more severe in Gwandu and Jega (3) and lowest in Bunza (1). Cutting-born infection is most prevalent (60%) than whitefly-born infection (3%) in the Local Government Areas surveyed. Polymerase chain reaction (PCR) results using specific primers for African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV) detected single infections of ACMV and EACMV in 62% and 13% of the positive samples respectively. Co-infections of ACMV and EACMV were detected in 11% of the tested samples. Continuous monitoring of cassava mosaic viruses and whiteflies population is required to provide appropriate management strategies of the disease in the State.