Impact of methyl jasmonate on Tetranychus urticae Koch in grapes Cv. Thompson Seedless

Abstract

Field experiment was conducted at Horticulture Research and Extension Centre, Vijayapura (Tidagundi), Karnataka, India to evaluate the bio-efficacy of Methyl jasmonate (MeJA) against spider mite, Tetranychus urticae Koch in grapes cv. Thompson Seedless during the year 2020-21 (forward pruning). The results revealed that two sprays of abamectin 1.9 EC at 0.3ml/l found to be superior in suppressing the eggs and mites population after first and second spray by recording 2.81 eggs and 1.98 mites per square inch of leaf respectively which was at par with MeJA+ Azadirachtin 10000 ppm at 1mM + 2ml/l with 3.08 eggs and 2.22 mites per square inch of the leaf respectivelyindicating the superiority of both the treatments against T.urticae. The next best treatments were MeJA Azadirachtin10000 ppm at 0.75mM + 2ml/l and MeJA + Azadirachtin 10000 ppm at 0.5mM + 2ml/l with 4.05, 4.14 eggs and 3.19, 3.29 mites per square inch of leaf respectively.