NEW TECHNIQUE IN THE CONTROL OF SWEET-POTATO WEEVIL USING SYNTHETIC SEX-PHEROMONE IN INDIA

An IPM schedule using synthetic sex pheromone (Z-3-dodecenol-E-2-buten oate) as the principal component against sweet potato weevil has been evaluated for the first time in India. The components of the IPM Progr amme were: (a) disinfecting the planting materials by dipping the slip s in monocrotophos 0.05% for 10 min; (b) installation of pheromone tra ps from the first day of planting at 10 m distance (one trap/100 m2) t o destroy the male weevils; and (c) re-ridging the crop at 30 and 60 d ays after planting. The continuous elimination of the male population by pheromone traps in the treatment has resulted in a drastic decline in the population build-up of the weevil and consequent reduction in t he damage, leading to increased production of marketable tubers over 5 3%. In the first season weevil damage was reduced from 33% to 9.7% and in the second season from 39% to 9.5% by adopting the IPM schedule. T he control field showed a four- to seven-fold increase in the pest pop ulation (516 to 741 in the control and 114 to 128 in the treatment).