Germplasm Screening and Evaluation of Bio-rational Insecticides Against Major Pod Borers in Pigeonpea

Abstract

The present investigation entitled “Germplasm screening and evaluation of bio-rational insecticides against major pod borers in pigeonpea.” carried out during Kharif 2016 to 2017 at C. R. C., Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut (U.P.) 250110. Out of twenty eight pigeonpea germplasm screened 4 germplasm viz., PI 397430, DA 12-2, ICP 7374 and DA 12-1 were found highly resistance (HR) against M. vitrata with PSR scale of ‘2’ and 5 germplasm viz., ICPL 5028, PI 397430, IPA 11-9, ICP 7374 and DA 12-1 were categorized in highly resistance (HR) group against H. armigera with PSR scale of ‘2’ during both the consecutive years, (Kharif, 2016 and 2017). The results on Maruca vitrata larval population reached its peak (22.00 and 21.00 larvae/10 plants) in all control plots on last week of October and first week of November (44th and 45th standard week) during Kharif 2016 and 2017. The results on Helicoverpa armigera larval population reached peak (17.33 and 16.00 larvae/10 plants) in all control plots on first week of November and last week of October (45th and 44th standard week) during Kharif 2016 and 2017. Among all the treatments, spinosad 45% SC @ 0.4 ml/l. water was found best in reducing the larval population of M. vitarat and H. armigera with 1.00 and 0.33 larvae per ten plants at nine days after second spray, respectively and followed by emamectin benzoate 5% SG @ 0.3 g/l. water with 1.50 and 0.66 larvae per ten plants. The highest larval population of M. vitarat and H. armigera was recorded with 21.00 and 15.66 larvae per ten plants, from untreated control, respectively. Among all the treatments, spinosad 45% SC @ 0.4 ml/l. water was found best with mínimum per cent pod infestation (7.33 %) against M. vitarat and (4.11 %) against H. armigera at nine days after second spray and followed by emamectin benzoate 5% SG @ 0.3 g/l. water with 7.50 and 4.67 per cent pod infestation. The effect of various insecticides on natural enemies population (C. septumpunctata, Mantis religiosa and spider) showed that the Bt kurstaki @ 2.5 g/l. water was found highly safe with maximum mean number of C. septempunctata (2.73 per plant), M. religiosa (0.33 per plant) and spiders (1.27 per plant) population after second spray, respectively and followed by NSKE 5%, achook 0.03% @ 5ml/l. water, neem oil 1500ppm @ 2.5 ml/l. water, diflubenzuron 25% WP @ 0.6 g/l. water, spinosad 45% SC @ 0.4 ml/l. water and emamectin benzoate 5% SG @ 0.3 g/l. water. The quinalphos 25% EC @ 2.5 ml/l. water was proved more toxic followed by novaluron 10% EC @ 1.3 ml/l. water against natural enemies population. The maximum and mínimum yield obtained from spinosad 45% SC @ 0.4 ml/l. water and B.t kurstaki @ 2.5 g/l. water with 15.77 and 6.30 q/ha, respectively. The highest C: B ratio (1:10.07) was calculated with emamectin benzoate 5% SG @ 0.3 g/l. water and lowest C:B ratio (1:2.15) was occurred with achook 0.03% @ 5ml/l. water.