Effects of Banana Weevil and Nematode Infestation on the Growth and Yield of Plantain (Mus4.Aab ) in Ghana

Abstract

Banana weevil (Cosmopolites sordidus Germar) and nematodes (particularly Pratylenchus coffeae [Zimmerman] Filipjev, Schuurmans and Stekhoven), are well known pests of plantain world-wide. An investigation was therefore conducted to quantify yield loss due to the individual and combined infestation of these pests on plantain in Ghana. From the studies on the effects of these pests on plantain using a natural nematode infestation and artificial and natural weevil population, it was concluded that weevil damage to plantain corms caused by the feeding and tunneling activity of the larvae had serious effect on the vitality of the plants. High densities of Pratylenchus coffeae associated with severe necrosis of the roots at flowering and harvest was the cause of a drastic deterioration of both primary and secondary roots. Results however, indicated that, with the occurrence of these two pests a much greater destruction of the corms, primary and secondary roots of the plants was readily expected. Weevil effect thus accounts for the high plant breakage after flowering, failure to reach maturity and a 34.8 % yield reduction. Nematodes effect on the other hand resulted in a complete failure of the majority of plants to flower, a total reduction in the productivity of the mat and a consequent yield loss of 63.7%.. Massive death was the immediate result when the interaction of these pests was pronounced at the early growth stage of the plants, whereas, failure to flower and the inability to reach bunch producing stage was the effect when infestation was delayed. The ultimate effect of this interaction was the drastic reduction in yield of about 85%. On the basis of the present study, the economic importance of these pests whether in combination or occurring separately on plantains in Ghana, cannot be overemphasized