Effects of mulch on banana weevil Cosmopolites sordidus (Germar) populations and damage in Uganda

Mulches have been shown to encourage banana weevils, presumably through enhanced water conservation. Some farmers report that leaving the soil at base of the banana mat free of mulch reduces banana weevil damage. Trials were conducted at the Kawanda Agriculture Research Institute and on a farm in Ntungamo District, Uganda to investigate the effect of mulch recessed from the mat versus mulches applied to the base of the banana mat on banana weevil populations, banana weevil damage, plant growth and fruit production. In both trials, banana weevil populations were higher in mulched than in unmulched systems, while damage was greater in mulched systems in Kawanda, but not in Ntungamo. Damage was similar between recessed and full mulched systems in Kawanda, while, contrary to expectation, damage was lower in full than in recessed mulches in Ntungamo. In both sites plants were larger in mulched than in unmulched systems with yield advantages of 18–27%. We conclude that mulching is beneficial for banana production, but that there are no banana weevil management advantages to mulching away from the base of the banana mat.