Efficacy of newer molecules against Plutella xylostella Linn.

A field experiment was conducted with 12 treatments viz., Bacillus thuringiensis @ 500 g.a.i.ha⁻¹, endosulfan @ 350 g.a.i.ha⁻¹, cypermethrin @ 60 g.a.i.ha⁻¹, spinosad @ 96.4 g.a.i.ha⁻¹, flufenoxuron @ 80, g.a.i.ha⁻¹, (imidacloprid + spinosad) @ 26.70 + 18.75 g.a.i.ha⁻¹, thiodicarb @ 350 g.a.i.ha⁻¹, cartap hydrocloride @ 375 g.a.i.ha⁻¹, indoxacarb @ 73 g.a.i.ha⁻¹, NSKE 5% and quinalphos @ 150 g.a.i.ha⁻¹ with one control, replicated thrice for two years to study the efficacy of these insecticides against Plutella xylostella Linn. The pooled data revealed that imidacloprid 17.8 SL + spinosad 2.5 SC @ 26.70 + 18.75 g.a.i.ha⁻¹ was recorded the lowest population of P. xylostella 2.33 larvae 10 plants⁻¹, 4.74 larvae 10 plants⁻¹, 10.26 larvae 10 plants⁻¹ and 17.94 larvae 10 plants⁻¹ on 3^rd, 7^th, 10^th and 14^th day after spraying which was followed by spinosad 45 SC @ 96.4 g.a.i.ha⁻¹ (2.55, 5.00, 12.05 & 19.96 larvae 10 plants⁻¹) and indoxacarb 14.5 SC @ 73 g a.i.ha⁻¹ (2.73, 5.13, 13.45 & 22.51 larvae 10 plants⁻¹) on 3^rd, 7^th, 10^th and 14^th days after spraying. On 3^rd and 7^th day after spraying, all these 3 treatments were at par with each other. However, on 10^th day after spraying imidacloprid 17.8 SL + spinosad 2.5 SC @ 26.70 + 18.75 g.a.i.ha⁻¹ was significantly superior over rest of the two treatments and on 14^th days after spraying it was found at par with spinosad 45 SC @ 96.4 g.a.i.ha⁻¹. The maximum larval population was recorded in untreated control 41.34, 54.45, 64.50 & 76.46 larvae 10 plants⁻¹ on 3^rd, 7^th, 10^th and 14^th days after spraying respectively. The highest yield of cauliflower curd was recorded 239.92 qt ha⁻¹ in plot treated with imidacloprid + spinosad which was significantly superior over spinosad @ 45 SC (214.42 qt ha⁻¹) and indoxacarb @ 14.5 SC (206.94 qt.ha⁻¹). The lowest yield was recorded in untreated control 88.03 q ha⁻¹.