Cyantraniliprole for the Control of Sweetpotato Weevil, 2017

摘要

The objective of the study was to evaluate the efficacy ofcyantraniliprole for control of sweetpotato weevils (SW) on tuberin a summer cultivation of sweetpotato, comparing with the conventionalinsecticide management of the pest with two applications ofchlorpyriphos in granular formulation, 2 and 4 mo after the planting.The experiment was carried out in a grower’s farm about 3000 m2in Yaese, about 5 km from the Okinawa Prefectural AgricultureResearch Center. On 9 May 2017, fipronil in granular formulation(BASF Japan, Tokyo, Japan) was applied with making ridges at aninterval of 80 cm as a conventional preplanting treatment by thefarmer. The farm was separated into seven parts after the plantingslips of a sweetpotato variety, ‘churakoi-beni’, on this day on eachridge at a 30-cm space. Since the grower did not agree with settingplots without insecticide applications after the planting for controlin the same number as the other insecticide treatments, control wasassigned to only one part in which three plots were made. In each ofthe rest six parts, four plots were set and two insecticide treatmentswere assigned randomly in each part: chlorpyriphos in granular formproduced by Nissan Chemical (Tokyo, Japan) or cyantraniliprole of10.3% by FMC Chemicals (Tokyo, Japan), diluted 4000 times withtap water in volume. Both insecticides were applied two times inthis experiment, on 22 Jul and 9 Sep 2017. Thus, two replicates ofeach insecticide treatment were assigned randomly in each of the sixparts. The rest part of the farm was divided into three plots, whereno insecticides were treated as control. Each plot covered four ridges,on each of which 26 were planted, and thus, 104 slips were presentin each plot. No pesticides other than those examined in this studywere applied throughout the cultivation. Three sweetpotato plantswere randomly selected in each quadrat on 10 Oct 2017 and dissectedto find and count infesting weevils in them. The data obtainedafter root-square transformation for numeral data and arc-sine forproportional ones were analyzed by ANOVA, followed by Fisher’sprotected LSD test at P 0.05.