Cassava mosaic disease and abundance of its whitefly vector in north-western Democratic Republic of Congo

Abstract

Cassava mosaic disease (CMD) is rampant in the Democratic Republic of Congo (DRC). The objective of this study was to assess the significance of CMD and abundance of its whitefly (Bemisia tabaci) vector, in the North-Western provinces of the DRC. A field study was conducted in three provinces, namely Mongala, North Ubangi, and South Ubangi, of north-western DRC, during February to March 2022. One hundred cassava (Manihot esculenta Crantz) fields, aged 3 to 9 months and at intervals of about 10 Km apart, were prospected during an epidemiological survey of cassava mosaic disease. The cassava cropping system (pure culture or intercropped), and the epidemiological parameters of cassava mosaic disease (incidence, severity of CMD, abundance of whiteflies, sources of infection) were assessed. Results showed that the prevalence of CMD and abundance of whitefly vectors in DRC were significantly different among the three provinces. The incidence was low in South-Ubangi (16.49%), medium in Mongala (21.83%), and high in North-Ubangi (44.63%). The severity of the disease in north-western DR Congo is very low and remains below level a value of 3 in all the provinces covered by this study. Whitefly abundance fluctuated between 1.49 (South-Ubangi) to 5.74 (Mongala). Infected cuttings were the main source of CMD infection in all the provinces. Cassava cultivated in monoculture had the highest populations of this victory.