STUDY ON THE MANAGEMENT OF SWEET POTATO WEEVIL(Cylas puncticollis (Boheman)) IN UMUAHIA, ABIA STATE

Abstract

Sweet potato weevil (Cylas puncticollis (Boheman)) infestation results in losses of millions of dollars annually. To protect crops in modern agriculture, integrated pest management can be a good alternative to synthetic insecticides. A field study was conducted in July to November 2018 on two orange-fleshed sweet potato varieties; Umuspo-1 and Umuspo-3 to study the management of sweet potato weevils. Two experiments: (i) Mulching with three plant leaves of Tephrosia vogelii, Alchornea cordifolia and Ageratum conyzoides and (ii) Earthing-up three levels (once, twice and thrice) were conducted. The experiments were laid out in randomized complete block design with three replicates. Parameters evaluated were, weevil population density, percentage colonization, root yield (marketable and unmarketable), yield-loss, percentage damaged roots and percentage control. Generally, control plots recorded higher weevil colonization, yield-loss, unmarketable and damaged roots. High significant (P ≤ 0.05) crop yield was found on plots mulched with T.vogelii (7.15t/ha), A.cordifolia (5.37t/ha) and A.conyzoides (5.79t/ha) than earthing[1]up thrice (3.53t/ha). Lower insect colonization occurred in plots mulched with T.vogelii (38.30%) and earthing-up thrice (45.0%). Results from these studies revealed the potential of mulching with insecticidal leaves and earthing-up thrice practices for effective management of sweet potato weevil. The botanicals used are common, ecofriendly, less