The Field Efficacy Trial of Three Pesticides for Controlling Plutella xylostella on the Qinghai Plateau

'Zhonggan No.21'cabbage was used as test material,control efficiency of 5% salt water dispersible granules,20% chlorine insects benzamide SC,3.5% Ruidan EC on the Plutella xylostella were studied.The results indicated that all of three pesticides had better control effect on Plutella xylostella,whose control efficacy was over 80% after three days,over 90% after seven days,and persistent period was above fifteen days.Therefore these pesticides can be use as alternatives in production of cabbage on the Qinghai Plateau.