COMPARATIVE ASSESSMENT OF INSECT PEST- DISEASE DYNAMICS AND THE PERFORMANCE OF GREEN GRAM UNDER DIFFERENT MICROCLIMATES

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dc.contributor.advisorMedhi, Kuldip
dc.contributor.authorYadav, Roshani
dc.date.accessioned2024-06-28T11:44:25Z
dc.date.available2024-06-28T11:44:25Z
dc.date.issued2023
dc.description.abstractField experiments were conducted in the Instructional-Cum-Research (ICR) Farm of Assam Agricultural University, Jorhat during kharif, 2022 and summer, 2023 with an objective to study the seasonal variation in incidence of insect pests and disease dynamics of green gram, and also to assess the performance of four cultivars of green gram viz., SGC 16, SGC 20, IPM 02-3 and MH 421 under three different microclimates created by manipulating sowing dates. The crop was sown on 11 September (D1), 28 September (D2) and 13 October (D3) during kharif, 2022, whereas it was sown on 13 February (D1), 28 February (D2) and 14 March (D3) during summer, 2023. The results revealed that aphid (Aphis craccivora) and jassid (Empoascakerri) population on green gram reached its peak in 50th and 42nd SMW, respectively in kharif season and 18th SMW in summer season. Pod borer (Helicoverpaarmigera) population recorded highest in 44th SMW during kharif and 20th SMW in summer seasons. Likewise, whitefly population (Bemisiatabaci) was recorded maximum in 46th and 16th SMW during kharif and summer seasons, respectively. In addition, Cercospora leaf spot (Cercospora canescens) and Moongbean Yellow Mosaic Virus (MYMV) disease infection reached its peak during 45thSMW in kharif and, 20th and 18th SMW, respectively during summer season. The Percent Disease Index (PDI) of Powdery mildew (Erysiphe polygoni) and Anthracnose (Colletotrichum sp.) was recorded highest in 51st SMW during kharif and 23rd SMW in summer season. In summer green gram, aphid population was significantly and positively correlated with maximum (0.55*) and minimum (0.45*) temperature; while it had a significant negative correlation with minimum temperature (-0.65**) duirng kharif season. Jassid and whitefly had positive and significant correlation with maximum and minimum temperatures. None of the weather variable had a significant impact on pod borer population during both of the season.Likewise, Cercospora leaf spot exhibited significant and positive correlation with temperature atripening phase in kharif green gram. The reliability of regression model (R2) developed based on insect pest and disease weather relationship were found to be varied within 0.04 to 0.77 and 0.24 to 0.85, respectively. The results revealed that among the varieties, MH 421 (539.1 kgha-1) performed better during kharif, whereas least yield (410.9 kgha-1) was observed when sown as summer crop. Poor performance of MH 421, can be indirectly referred from a depletion of 26.9% of intercepted PAR (iPAR) in summer crop relative to kharif crop due to low canopy growth. In contrary, SGC 16 maintained its performance in both kharif (491.2 kgha-1) and summer (512.5kgha-1) seasons. Mainly, substantial difference in plant height, LAI, above ground biomass and number of pods per plant corresponding to early and late sowings during kharif and summer, respectively defines the yield of the crop. In case of early (D1) sowing date, sufficient moisture is available during kharif season, whereas less moisture is available in summer season for supporting initial crop establishment. The mean percentage of iPAR was found 3.4% (SGC 16), 8.4% (SGC 20) and 9.6% (IPM 02-3) higher under late (D3) sown summer season crop relative to kharif season. Overall, protein content in seeds of green gram varied from 22.07 to 24.50%, irrespective of sowing dates and found maximum in SGC 20 (>24.0%); and minimum in SGC 16 (22.0%) in kharif and MH 421 (21.6%) in summer. Maximum protein content was recorded in D2 (23.8%) and D3 (23.9%) corresponding to kharif and summer season, respectively. Moreover, negative association was observed among seed yield and protein content of seedsof green gram.
dc.identifier.urihttps://krishikosh.egranth.ac.in/handle/1/5810211116
dc.language.isoEnglish
dc.subAgricultural Meteorology
dc.themeCOMPARATIVE ASSESSMENT OF INSECT PEST- DISEASE DYNAMICS AND THE PERFORMANCE OF GREEN GRAM UNDER DIFFERENT MICROCLIMATES
dc.these.typeM.Sc
dc.titleCOMPARATIVE ASSESSMENT OF INSECT PEST- DISEASE DYNAMICS AND THE PERFORMANCE OF GREEN GRAM UNDER DIFFERENT MICROCLIMATES
dc.typeThesis
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