Infestation levels of banana weevil, Cosmopolites sordidus Germar (Coleoptera : Curculionidae), in banana plants established from treated propagules in Uganda

Spread of banana weevil, Cosmopolites sordidus Germar, occurs primarily thr ough infested suckers used for propagation. The use of clean planting mater ial, hom which weevils have been removed by paring and/or hot-water treatme nt, has been recommended as a cultural control strategy. In this study, two trials were undertaken to quantify the effects of cleaned planting materia l on the level of weevil and nematode infestation and on plant growth and y ield. Treatments included: (1) untreated suckers (controls), (2) pared corm s and (3) pared and hot-water-treated corms. Initial weevil populations wer e lower in plots established with cleaned planting material than in control s. In Trial 1, weevil numbers in pared and pared/hot-water-treated material were lower than in control plots for up to 11 months, while in Trial 2, pl ots established from pared and pared/hot-water-treated planting material ha d lower numbers of the pest for 27 months and 20 months, respectively. Weev il damage levels in controls were 7-200 % higher than in plots cultivated f rom treated planting material for the entire crop cycle. All treatments had similar levels of weevil damage in the first ratoon. Hot-water treatment a fforded excellent nematode control for the duration of both trials. In both trials, treated plants had faster plant maturation rates and lower levels of plant loss due to pests. In Trial 1, 21 % of plants in the control crop were lost to weevils and nematodes compared to 2 % in treated plots. In Tri al 2, plant loss to weevil and nematodes was 34 % in controls, 6 % in pared and 2 % in hot-water treatments. Eventual bunch size was similar among tre atments in both trials. However, plots with treated plants provided higher yields as a greater number of bunches was harvested during the course of th e study.