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Birsa Agricultural University, Ranchi

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2021 - 20232
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Subject: Agricultural Entomology × End date: 2023 × Start date: 2020 ×
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    ThesisItemOpen Access
    SEASONAL INCIDENCE AND MANAGEMENT OF MAJOR INSECT PESTS OF CABBAGE (Brassica oleracea var. capitata L.)
    (Birsa Agricultural University, Ranchi, 2023) Rahul Sahu; M.K. Chakravarty
    Cabbage, Brassica oleracea var. capitata (L.) is most commonly grown cole crop in Jharkhand. Cabbage, like other cole crops, is attacked by wide range of pests right from germination to harvest; among them the diamondback moth, aphid and cabbage semilooper, are responsible for appreciable losses of cabbage. The current study, "Seasonal incidence and management of major insect pests of cabbage (Brassica oleracea var. capitata L.)," was carried out at the Vegetable Research Area of the Department of Horticulture, Birsa Agricultural University, Ranchi, Jharkhand, during Rabi, 2021-22, to observe the diversity of insect pests and natural enemies, seasonal incidence of major pests in relation to important weather parameters, and to assess the bio-efficacy of some safer synthetic insecticides against major pests of cabbage. Based on the findings, ten species of insect pests and four species of natural enemies were observed on cabbage (Var. "Golden Acre") during the experiment period. The diversity study at different growth stages of cabbage indicated that the highest species richness of insect pests was recorded during the seedling stage, while the highest diversity and evenness were found during the heading stage. In the case of natural enemies, the seedling stage recorded the highest species richness, while diversity was highest during the pre-heading stage and evenness was highest during the heading stage.The incidence of cabbage aphid, diamondback moth and cabbage semilooper started in the first week of December (48th SMW) which gradually increased and reached its peak population in the 2nd, 7th and 6th SMW, respectively. The correlation analysis revealed that the aphid population had significant negative correlation with maximum temperatures and sunshine hour, and significant positive correlation with rainfall whereas the populations of diamondback moth and cabbage semilooper had significant negative correlation with maximum temperature. The bio-efficacy of synthetic insecticides such as Chlorantraniliprole 18.5%SC, Difenthiuron 50%WP, Emamectin benzoate 5%SG, Fipronil 5%SC, Flubendiamide 39.35%SC, Pyridalyl (10% EC), and Spinosd (45% SC) against major insect pests of cabbage revealed thatDifenthiuron 50%WP and Fipronil 5%SC wererecorded the most effective insecticides in reducing the aphid populations whereas, the application of Pyridalyl (10% EC) and Spinosd (45% SC) recorded the most effective insecticides against the larval populations of diamondback moth and cabbage semilooper. The treatment Pyridalyl 10%EC also recorded the highest yield (224.71 q ha-1), highest increase in yield over control (42.15 %) and highest benefit-cost ratio (19.2:1).
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    ThesisItemOpen Access
    MANAGEMENT OF INSECT PESTS OF HYBRID MAIZE WITH PARTICULAR REFERENCE TO FALL ARMYWORM (Spodoptera frugiperda J.E. SMITH)
    (Birsa Agricultural University, Ranchi, 2021) Kumar Gupta, Rahul; Chakravarty, M.K.
    Maize (Zea mays L.) is known as the queen of cereals due to its diverse usages and highest yield potential and plays a very important prominent role in the food securing and economic wellbeing of the farming community of Jharkhand. In recent years an invasive insect pest species fall armyworm causing wide spread damage to maize crop worldwide has been reported. The present study entitled “Management of insect pests of hybrid maize with particular reference to fall armyworm (Spodoptera frugiperda J.E. Smith)” was conducted during Kharif 2019 at the Agriculture Research Farm of Birsa Agricultural University, Ranchi, Jharkhand. The experiment was planned to survey fall armyworm infestation in Ranchi and Ramgarh districts, to study of population dynamics of fall armyworm and other pests in hybrid maize and to evaluate the efficacy of various insecticides against fall armyworm and stem borer on maize. Survey of Fall Armyworm in 6 villages from 2 districts of Jharkhand were studied for the incidence of fall armyworm, leaf folder, stem borer, grass hopper, cob borer and aphids. The infestation pattern seen in Ranchi district indicated that maximum incidence of fall armyworm was noticed with 64% infestation followed by leaf folder (38.33%), stem borer (26.5%), aphids (21.66%), cob borer (15.6%) and grasshopper (7.83%). Similarly, in Ramgarh district, maximum insect infestation of fall armyworm of 67.66 per cent was seen followed by stem borer (25.83%), leaf folder (19%), aphids (17.33%), cob borer (10.6%) and grasshopper (8.98%). Population dynamics study of various insects pests in hybrid maize revealed that the peak larval population of fall armyworm was observed in 37th SMW whereas the peak larval population of leaf folder was observed 33rd SMW. However, the peak population of aphids was noticed in 38th SMW, whereas, the peak larval population of stem borer was appeared in 37th SMW. The peak larval population of beneficial arthropods like ladybird beetle was appeared in 38th SMW and that of spider was appeared in 39th SMW whereas, the peak population of hover fly was appeared in 41st SMW. Comparative efficacy of various insecticides against fall armyworm and stem borer on maize indicated that after the first spray, the extent of reduction in S. frugiperda population over control was highest in Spinetoram (69.50%) treated plots followed by Emamectin benzoate (46.54%) and lowest in Metarhizium anisopliae treated plot where it registered only (26.10%) reduction in insect population as compared to control. The effect of ten insectides after second spray resulted in 40.08% to 85.95% reduction against the untreated control. Among all the insecticides used, Spinetoram has showed maximum reduction (85.95 %) followed by Emamectin benzoate (61.98 %) and the lowest per cent reduction of 40.08 % was observed in Metarhizium anisopliae treated plot. The efficacy of first spray, on the reduction of Chilo partellus population ranged from 24.09 to 87.26 % in various treatments. Spinetoram registered 87.26% reduction over control, followed by Emamectin benzoate (72.67%). The efficacy of Metarhizium anisopliae was very less resulting in only 24.09% reduction in insect population. After the second spray, the per cent reduction of Chilo partellus population varied from 27.65 to 87.30% in various treatments. The maximum larval population reduction was recorded in Spinetoram (87.30%) plot, followed by Emamectin benzoate (67.12%). In confront Metarhizium anisopliae treated plot has the lowest effect on larval population with only 27.65 per cent reduction in insect population. Highest cost benefit ratio was obtained from Emamectin benzoate (1:7.80), treated plot followed by Lambda cyahalothrin (1:7.16) and the lowest cost benefit ratio was obtained in Chlorantraniliprole (1:3.09) treated plot.