Bio-efficacy of Mortel (Fipronil 0.3 G) against Pink Stem Borer, Sesamia inferens in Wheat

Investigations on toxicity of new insecticide namely Mortel (Fipronil 0.3 G) at 15, 17.5 and 20 kg/ha in comparison to Dursban (chlorpyriphos 20 EC) at 3 l/ha as check insecticide were carried out against Pink Stem borer, Sesamia inferens, Walker (PSB) in wheat at farmer's field in district Amritsar and Gurdaspur during the rabi season 2020–21. Among the different dosages of Fipronil 0.3% GR (Mortel) tested, Fipronil 0.3% GR @ 20 kg/ha has recorded maximum reduction in tillers damage and higher grain yield of wheat. Highest grain yield of 51.75 and 50.67 q/ha was obtained when Fipronil 0.3% GR (Mortel) was used @ 20 kg/ha in district Amritsar and Gurdaspur, respectively. No dead heart was found at end of first week of application when Fipronil 0.3% GR @ 20 kg/ha was used in Amritsar districts while 0.08 per cent dead hearts were recorded after first week of application in Gurdaspur district. There was no statistical difference in natural enemy count recorded after 1, 2 and 3 weeks of treatments in different dosages of Fipronil 0.3% GR and was statistically on par with that of the untreated check indicating that all the tested dosages of Fipronil were safer to the natural enemies. There were no phytotoxicity effects of Fipronil 0.3% GR on wheat even at higher dosages. As Fipronil @ 20 kg/ha has recorded highest reduction in the tillers damage due to PSB attack and highest grain yield, the highest dosage i.e. Fipronil @ 20 kg/ha may be recommend as an alternative insecticide for the effective management of pink stem borer in wheat.