EFFICACY OF SOME PROMISING CHEMICAL INSECTICIDES FOR CONTROLLING RICE STEM BORER, LEAF ROLLER AND BROWN PLANT HOPPER

Abstract

The experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University (SAU), Dhaka-1207, Bangladesh, during the period from November 2012 to May 2013 (Boro season) to study the efficacy of some promising chemical insecticides for controlling rice stem borer, leaf roller and brown plant hopper. The experiment was laid out in a Randomized Complete Block Design with three replications with six treatments. Treatments were T1= Untreated control, T2= Virtako 40 WG (Thiamethoxam 20% in combination with Thiamethoxam Chlorantraniliprole 20%) @ 75 g/ha, T3= Cartap hydrochloride @ 150 g/ha, T4= Cartap hydrochloride @ 75 g/ha in combination with Thiamethoxam 25% @ 60 g/ha, T5= Cartap hydrochloride @ 100g/ha in combination with Thiamethoxam 25% @ 60 g /ha, T6= Cartap hydrochloride @ 150 g /ha in combination with Thiamethoxam 25% @ 60 g /ha. Among the treatments, T6 comprising Cartap hydrochloride @ 150 g/ha along with Thiamethoxam @ 60 g/ha was found most effective in reducing the stem borer infestation than sole Cartap hydrochloride (T3) or any other treatments. On the other hand, T4 comprising Cartap hydrochloride @ 75 g/ha in combination with Thiamethoxam @ 60 g/ha was found most effective in reducing the rice leaf roller infestation and brown plant hopper population in rice field. Though T6 was the most effective against rice stem borer but its level of reduction was more or less similar to that of T4 which was comprised of lower dose of Cartap hydrochloride along with Thiamethoxam and thus T4 was better than T6.