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20211
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Subject: Entomology × Author: Jyotsana × End date: 2021 × Start date: 2021 ×
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    ThesisItemOpen Access
    Study of important insect-pests and management of whitefly Bemisia tabaci (Gennadius) on black gram
    (CCSHAU, Hisar, 2021-07) Jyotsana; Verma, Tarun
    Studies on important insect pests, screening of genotype for resistance and evaluation of biopesticides against whitefly, Bemisia tabaci (Gennadius) on black gram were conducted at CCS HAU, Hisar during kharif 2020. Incidence of whitefly commenced in 30th SMW and continued till 39th SMW with its peak population in 31st SMW. Empoasca kerri incidence recorded only during 37th SMW. Clavigralla gibbosa and Riptortus pedestris commenced in 31st SMW and remained upto 37th SMW, with its peak population on genotype MH 479 and UH 1 in 33rd and 35th SMWs, respectively. Maruca vitrata infestation commenced in 36th SMW and remained upto 38th and 39th SMW on genotype MH 479 and UH 1, respectively with its peak population on MH 479 in 36th SMW and on UH 1 in 37th and 38th SMWs, respectively. No infestation of Helicoverpa armigera and Spodoptera litura was recorded. Trichoplusia ni infestation was only observed in 37th SMW on genotype UH 1 and 32nd and 37th SMW on genotype MH 479. Coccinella septempunctata population commenced in 30th SMW and continued till 39th SMW with its peak population in 31st SMW on MH 479 and 31st and 33rd SMW on genotype UH 1. Spider population commenced in 30th SMW and continued till 38th SMW in MH 479 and 39th SMW in UH 1, with its peak population being recorded in 35th SMW on MH 479 and 34th and 35th SMW on UH 1. Significant and negative correlation was observed between whitefly adult population and rainfall. Highly significant and negative correlation was observed between spotted pod borer larvae and wind speed. Among different genotypes, PU 11-9 harboured minimum nymphal population (1.74 nymphs/3 leaves) being at par with genotype IPU 2000-1 (2.25 nymphs/3 leaves), PU 11-10 (2.15 nymphs/3 leaves) and PU 11-15 (1.76 nymphs/3 leaves). Maximum nymphal population (5.33 nymphs/3 leaves) was reported on UH 04-06 which is at par with ICC 11668 (4.92 nymphs/3 leaves) and Mash 114 (5.05 nymphs/3 leaves). Minimum and maximum whitefly adult population was recorded on genotype IPU 2000-1 (17.77 adults/plant) and on IPU 4 (25.55 adults/plant). Based on whitefly resistance index (WRI), IPU 2000-1 was found to be moderately susceptible and all other genotypes as susceptible. Among the tested biopesticides, the maximum mean reduction in adult population of whitefly (26.47%) was found with castor oil 1% followed by Azadirachtin 300 ppm @ 5ml/l (19.96 %) and neem oil 1% mixed with castor oil 1% (19.51 %). However, maximum yield was obtained from neem oil 1% (50.07 kg/ha) which is at par with Azadirachtin 300 ppm @ 5ml/l (48.03 kg/ha). Maximum and minimum additional yield over control was observed in Neem oil 1% (42.96 kg/ha) and Beauveria bassiana (2.22 kg/ha). No significant effect on natural enemy population was observed in any biopesticide.