Evaluation of Neem (Azadirachtaindica) Seed Extracts for theControl of Mealy Bug (Dysmicoccus Spp.) and Mealy Bug Associated Pineapple (Ananas Comosus) Wilt

Abstract

Mealybug associated pineapple wilt is a major constraint to pineapple production in Ghana. Aqueous and methanolic neent seed extracts and a standard insecticide, dimethoate were evaluated for their efficacy against the pineapple mealybug in laboratory, screen house and field studies. The pineapple cultivar used was Smooth Cayenne. In the screen house treated suckers were planted in plastic pots filled with soil. Destructive sampling techniques were applied to obtain the number of live mealybugs at two weekly intervals for 10 weeks. In the screen house experiment, methanolic neem seed extract at the highest dosage (6 g/1) was found to be most effective treatment against the pineapple mealybugs. In the field, dimethoate and methanolic neem extract were equally effective in reducing the mealybug population than the control. The population of mealybugs was reduced to almost zero in dimethoate and methanolic neem extract treated plants. The extract also promoted healthy leaf development, reduced wilting and rotting of pineapple roots.