Management of major insect pests of black gram under dryland conditions

Abstract

Field experiments were conducted during rabi 2011 and 2013 to evaluate the efficacy of different insecticidal treatments against aphid, Aphis craccivora Koch, leafhopper, Empoasca kerri Pruthi, defoliator, Spodoptera litura (Fab.) and pod borer, Helicoverpa armigera (Hub.) on black gram. The results showed that seed treatment with thiamethoxam 25 WG @ 3 g/ kg of seed + spray with thiamethoxam 25 WG @ 0.4 g/ l recorded the lowest population of aphids (1.60, 1.45 no. /plant) and leafhoppers (2.36, 2.12 no./ plant) followed by spraying of imidacloprid 17.8 SL @ 0.4 ml/ l with 83.96, 87.45 kg and 66.13, 71.61 per cent reduction over control, respectively after second round of spraying in the fields trials I and II. Indoxacarb 14.5 SC @ 1 ml/ l provided an effective control of S. litura and H. armigera which recorded 0.04, 0.00 and 0.09, 0.03 nos of larvae/plant at 7th day after the second application in the field trial I and II, respectively, which was at par, with sponsored 45 SC @ 0.4 ml/ l (0.08, 0.07 and 0.13, 0.13 at 7 DAT of second application) but was significantly better than the untreated control. Thus, seed treatment with thiamethoxam 25 WG @ 3 g/kg of seed + spray with thiamethoxam 25 WG @ 0.4 g/ l and indoxacarb 14.5 SC @ 1 ml/ l proved effective against sucking pests and borers of black gram, respectively and can be recommended for their use in black gram ecosystem.