Biorational management and mycosis studies of grape thrips, Rhipiphorothrips cruentatus H.

Abstract

Field experiment was conducted during 2017-18 to test the bioefficacy of certain biorational insecticides against thrips Rhipiphorothrips cruentatus Hood on grapevine at the Department of Horticulture, MPKV, Rahuri, India. Among botanical insecticides, neem oil 2% (4.09/shoot) was the most effective treatment followed by, karanj oil (4.51/shoot) and commercial azadirachtin formulation (neemazol) (5.08/shoot). The entomopathogenic fungi, Lecanicillium lecanii recorded 4.24/shoot followed by Metarhizium anisopliae (4.87/shoot) and Beauveria bassiana (5.34/shoot). However chlli methanolic extract (6.29/shoot), garlic methanolic extract (6.78/shoot), chilli water extract (6.85/shoot) and garlic water extract (7.08/shoot) were least effective treatments. Incremental Cost Benefit Ratio (ICBR) in respect of different treatments ranged from 1.30 to 7.92. The highest ICBR of 1:7.92 was recorded with emamectin benzoate 5SG followed by L. lecanii (1:6.34) and M. anisopliae (1:5.32). Although neem oil and karanj recorded higher reduction of thrips population, they had lower cost benefit ratio due to high dose and its cost. The pathogenesity of L. lecanii and
M. anisopliae was also confirmed through mycosis test.