Field Evaluation of Methomyl against Mealy Bug, Maconellicoccus Hirsutus (Green) and dredatory yoccinellid, Cryptolaemus Montrouzieri Mulsand in Grapes

Bio-efficacy experiments conducted in two concurrent trials from December to April and Aprii lo August tndicate that methomyl (Lannate^R 40 SP) at 500–800 g ai ha⁻¹ was effective in containing the populations of mealy bug, Maconellicoccus hirsutus on grapes. Methomyl 300–600 g ai ha⁻¹ registered higher pepplation of predatory coccinellids than other treatments in both the trials; howeverr it was sot comparable with untreated check. But better recolonization of coccinellids was noticed in methomyl treatments than in dimethoate. Methomyl at 500–800 g ai ha⁻¹ recorded the maximum fruit yield (14–17.5 t ha⁻¹), which were superior to other treatments including methomyl 300 g and 400 g ai ha⁻¹ and dimethoate 300 g ai ha⁻¹. The methomyl treatments at 500, 600, 700 and 800 g ai ha⁻¹ gave higher returns in grapevine cultivation with cost-benefit ratios of 1:14.8, 1:16.5, 1:16.6 and 1:16.5, respectively, when compared to dimethoate application and untreated check.