Spatio-temporal distribution of banana weevil Cosmopolites Sordidus [Germar] and nematodes of various genera in Uganda: A case of smallholder banana orchards in Western Uganda

Abstract

Smallholder farmers’ banana orchards in Western Uganda were used to study the spatio-temporal factors influencing the distribution of banana weevils and parasitic nematodes in tissue culture and non-tissue culture banana types using Nested case control design. Nematodes were extracted from randomly collected composite banana root samples from 20 banana orchards. The banana weevils were trapped in the rainy and dry seasons. A total of 1,280 banana genets were surveyed to determine weevil and nematode densities. Interactions between season and locations with high banana weevils and nematodes densities significantly negatively influenced the distribution of tissue culture and non-tissue culture banana in space and time. Both tissue culture and conventional bananas are prone to banana weevil and nematode infestations. Infestation with weevils and nematodes were higher for tissue culture banana in the dry season. Kiruhura district had a higher density for banana weevils (Cosmopolites sordidus [germar]) while Ibanda district had higher nematode densities. Helicotylenchus multicinctus and Radopholus similis were found most prevalent. This knowledge is not only important in shaping the adoption and sustenance of the adopted banana types, but also can form a basis for developing affordable strategies to lower the occurrence of banana weevil and nematodes below the threshold level in smallholder banana farms of Uganda.