Screening of Genotypes and Evaluation of Biorational And Botanical Insecticides Against Major Pod Borers in Black Gram

Abstract

The present investigation entitled “Screening of genotypes and evaluation of biorational and botanical insecticides against major pod borers in black gram” was carried out during Kharif, 2018 and 2019 at Crop Research Centre, Chirodi of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut (U.P.). During the crop season (Kharif, 2018 and 2019), twelve species of insect-pests and two natural enemies were observed on black gram at different stages of crop growth. Among these spotted pod borer, gram pod borer, bihar hairy caterpillar and leafhopper were recorded as major insect-pests. Whereas, remaining all other insect-pests were recorded as minor pests. The M. vitrata larval population attended its peak (18.33 and 16.33 larvae per ten plants) on second week of October and third week of October (41st and 42nd standard week) during Kharif, 2018 and 2019 and H. armigera larval population reached its peak (12.00 and 10.33 larvae per ten plants) on 42nd standard week (third week of October) during both the years. Fifteen genotypes of black gram were screened for their relative resistance against M. vitrata and H. armigera. Out of these two genotypes viz., KU-99-05 and Azad Urd-1 were found with minimum pod infestation of 7.67 and 9.67 per cent, respectively and categorized as resistant (R) against M. vitrata and four genotypes viz., KU-99-05, Azad Urd-1, Shekhar-2 and PU-6 were observed with minimum pod infestation of 5.83, 6.17, 8.50 and 9.83 per cent, respectively and these genotypes classified as resistant (R) against H. armigera during both the consecutive years i.e. Kharif, 2018 and 2019. Among all the 15 genotypes of black gram no genotype was found susceptible with respect to pod damage (> 30% pod damage) against M. vitrata and H. armigera. Among all the treatments, coragen 20% SC @ 0.3 ml/l. water was found most effective in reducing the larval population of M. vitrata and H. armigera with 0.67 and 0.00 larvae per ten plants and followed by spinosad 45% SC 0.6 ml/l. water with 1.67 and 0.50 larvae per ten plant, respectively. The highest larval population of M. vitrata and H. armigera was recorded in untreated control with 18.33 and 12.17 larvae per ten plants, respectively. Among all the treatments, coragen 20% SC @ 0.3 ml/l. water was observed best with mínimum pod infestation of 7.00 and 5.17 per cent against M. vitrata and H. armigera, respectively. The effect of various bio-rational and botanical insecticides on natural enemies population (Coccinellids and spiders) showed that the NSKE (5%) was found most safe treatment against adults of C. septempunctata and spiders population with 4.67 and 2.83 per ten plants and followed by achook (0.03%) @ 7.5 ml/l. water with 4.17 and 2.50 per ten plants, respectively. The cartap-hydrochloride 50% SP @ 1.25 g/l. water was found highly toxic treatment against natural enemies population. The maximum grain yield of 8.65 q/ha was recorded in the plots treated with coragen 20% SC @ 0.3 ml/l. wáter and mínimum grain yield was found in untreated control with 2.00 q/ha. The maximum incremental cost benefit ratio (1:6.01) was recorded in the treatment emamectin benzoate 5% SG @ 0.5 g/l. water and minimum ICBR of 1:0.89 was found in the treatment achook (0.03%) @ 7.5 ml/l. water.