Evaluation of newer insecticides against leaf hopper on Bt cotton

Abstract

Evaluation studies were carried out for management of leaf hoppers on Bt cotton during 2012-13 at three different locations. The pooled results revealed that minimum population of leaf hoppers was recorded in the treatment fipronil 5 SC (0.075%) and it was at par with treatment diafenthiuron 50 WP (0.08%) and imidacloprid 30.5 SL (0.005%). Next best treatment was buprofezin 25 SC (0.05%). Significantly highest seed cotton yield of 19.43 q/ha was harvested in application of treatment fipronil 5 SC (0.075%) followed by diafenthiuron 50 WP (0.08%) and imidacloprid 30.5 SL (0.005%) with 18.66 and 18.19 quintal per hectar, respectively. Highest monetary return Rs. 33,409 per ha was also observed in the treatment fipronil 5 SC (0.075%) followed by imidacloprid 30.5 SL (0.005%) (Rs. 30113 per ha) and diafenthiuron 50 WP (0.08%) (Rs. 28340 per ha) whereas in terms of higher incremental cost benefit ratio, imidacloprid 30.5 SL (0.005%) was found superior which recorded 1: 13.3 followed by fipronil 5 SC (0.075%) (1: 8.9).

Comparative Field Efficacy of Entomopathogenic Fungi and Certain New Insecticide Molecules Against Leafhoppers, Amrasca Devastans (Distant) on Bt Cotton

“…However, all the treatments were able to produce significantly superior seed cotton yield when compared to that of untreated control (13.9 q/ha) which recorded the lowest yield (Table . 1). The results are in concurrence with those of Chandi et al (2016) and Nemade et al (2017) who reported high seed cotton yield from flonicamid 50 WG in cotton. The new molecules such as flonicamid 50 % WG, diafenthiuron 50 % WP and buprofezin 25 % SC can be used for effective control of leafhoppers in Bt cotton as a substitute for conventional insecticides in case of severe incidence.…”

“…The percent reduction in leafhopper population over untreated control was above 70 per cent with flonicamid 50 % WG and it 144 was above 60 per cent with diafenthiuron 50 % WP and buprofezin 25 % SC. But it was below 50 per cent with the remaining treatments such as 5 % NSKE, V. lecanii @ 10 g/lt and M. anisopliae @ 10 g/lt (Table .1) The present findings are in close proximity with Nemade et al (2017) who reported that flonicamid is highly effective against leafhoppers in Bt cotton. Chandi et al (2016) also reported that the percent reduction in leafhopper population was the highest with flonicamid 50 WG which is in concurrence with present findings.…”

“…Chandi et al (2016) also reported that the percent reduction in leafhopper population was the highest with flonicamid 50 WG which is in concurrence with present findings. The efficacy of diafenthiuron and buprofezin against the sucking pests in cotton and other crops was reported earlier (Sreekanth and Reddy, 2011;Zala et al, 2014;Bajya et al, 2016;Kumar et al, 2015;Nemade et al, 2015;Jadhav et al, 2017) in cotton. The better efficacy of insecticide molecules with new chemistries over entomopathogenic fungi and other biopesticides was reported earlier (Kalyan et al, 2012;Saner et al, 2013), thus confirming the present findings.…”

Timings of treatments determine the effectiveness of insecticides in controlling the cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

“…Earias insulana (Boisd.) (Saleh et al, 2013); emamectin benzoate and lambda-cyhalothrin against the larvae of cotton bollworms (Patel, 2013); profenophos, lambda-cyhalothrin, cypermethrin and chlorpyriphos against PBW in cotton (Zaki et al, 2015); profenophos against the larvae of S. litura (Razak et al, 2014) and PBW (Moustafa and Salem, 2019). The significant decrease in the pest control efficacy of the test insecticides was observed from >80% in pre-larval release treatment to <49% in the treatment of post-larval release and entry inside the green bolls.…”