The effects of banana weevil, Cosmopolites sordidus, damage on highland banana growth, yield and stand duration in Uganda

A trial to determine yield losses in East African highland banana (cv. Atwalira) to banana weevil was run between 1994 and 2001 at the International Institute of Tropical Agriculture's Sendusu Farm in Namulonge, Uganda. Banana weevil adults were released into weevil-infestation plots, while weevils were excluded from controls by trapping and later application of chlorpyrifos. Weevil migration and reproduction in control plots reduced treatment differences in damage during the first 3 yr. Thereafter, weevil damage was heavy in infested plots and negligible in controls. High levels of weevil attack resulted in reduced bunch weights, plant losses, mat disappearance and fewer harvested bunches, with estimated yield losses averaging 42% over the final 4 yr of the trial. The data confirm the importance of banana weevil as an important production constraint of highland banana and support farmer reports that banana weevil attack contributes to shortened plantation life.