Evaluation of insecticides doses against onion thrips, Thrips tabaci Lind.

Abstract

The objective of this work was to evaluate insecticides against onion thrips, Thrips tabaci. The treatments used were: deltamethrin + triazophos (CE) 3.0 + 105.0 g a.i./ha, 4.5 + 157.5 g a.i./ha, and 6.0 + 210.0 g a.i./ha; cypermethrin (CE) 120.0 g a.i./ha, 150.0 g a.i./ha and 50.0 g a.i./ha; lambdacyhalothrin (WP) 15.0 g a.i./ha; alternated spraying of lambdacyhalothrin (CE) 15.0 g a.i./ha and pirimiphos-methyl (CE) 120.0 g a.i./ha; lambdacyhalothrin (CE) 15.0 g a.i./ha; pirimiphos-methyl (CE) 120.0 g a.i./ha; deltamethrin (CE) 7.5 g a.i./ha; check. The treatments lambdacyhalothrin (all doses) and cypermethrin were effective against onion thrips, but only cypermethrin 150.0 g a.i./ha were superior in yield. The yield didn't differ among the majority of the treatments with insecticide and the untreated check, probably due to the late beginning and the relatively reduced number of sprayings.