Efficacy of Lemon Extracts in Controlling Mealy Bugs of Stored Yam (Dioscorea rotundata)

Abstract

Background: The use of plant extracts in controlling mealy bugs is widespread especially on stored products. Despite this, research on lemon extracts, which is known to be very effective against some insect pests are limited. We assessed the repellent ability of lemon extracts in controlling mealy bug infestation and observed if there was any added benefit of the extract in retarding sprouting of yams in storage. Methods: We used the complete randomized design with three treatments and three replications. The treatments consisted of lemon peels, lemon leaf extracts and a control. Ten tubers of Pona white yam variety were rubbed on the periderm with each treatment and placed on a shelf. Two yam tubers naturally infested with mealy bugs were placed at the edges of each replication to serve as sources of infestation. Result: Results showed that yam tubers treated with lemon peel extracts recorded relatively low mealy bug counts compared to untreated ones and, tubers treated with lemon extracts recorded relatively higher weights compared to those without any treatment. Furthermore, there were no significant differences in neither counted mealy bugs nor yam weight per treatment between extracts from leaves or peels. Lemon extract treatments did not affect sprouting and shelf life of tubers in storage. We conclude that lemon extracts are effective repellents of mealy bugs and can be promoted as a safe bio pesticide for stored yam against mealy bug infestation.