Bioefficacy and Phytotoxicity of Clothianindin 50 WDG against Thrips and Mealybugs in Grapevine

Abstract

Two separate experiments were conducted in the field to examine the effectiveness of clothianidin 50 WDG against thrips and mealybugs that were infesting grapevines. The findings highlighted that applying clothianidin 50 WDG @ 1000 g ha-1 proved highly efficient in curbing the population of the sucking pests, outperforming lower doses of the compound. Following two rounds of soil drenching spaced 14 days apart, there was an average reduction of 76.63% for thrips and 78.09% for mealybugs. Other concentrations of clothianidin 50 WDG (600, 500 and 400 g ha-1) demonstrated significant reductions in the populations of thrips and mealybugs, exhibiting a similar level of efficacy as the standard check (Methomyl 40 SP and Buprofezin 25 SC) in all field experiments. Notably, no signs of harm to the grapevine were observed at any of the tested doses. Clothianidin 50 WDG @ 1000 g ha-1 resulted in the highest grape yield, producing 14.25 and 8.94 kg vine-1 at Madhampatti and Kalampalayam, respectively. Throughout the clothianidin 50 WDG treatment plots, the presence of natural enemies was noted and their activity remained unaffected, indicating no adverse impact on the natural enemy population.