Rai, DineshMahto, Kumari Sushma2020-11-172020-11-172020M/PP/265/2018-19https://krishikosh.egranth.ac.in/handle/1/5810155121Soil is an oligotrophic medium for the fungal growth. Fungi are an important component of soil microbiota. Soil fungal diversity plays an important role in maintenance of soil conditions and soil health. In Bihar, especially in Samastipur district, very less information is available regarding soil inhabiting fungi of cultivated and uncultivated fields. Hence, the investigation on “Studies on Soil fungal diversity in relation to soil health and its implication in plant disease management” was undertaken during the course of study to explore the mycoflora diversity and different plant and soil factors affecting them. Ten soil samples were collected from different villages of Samastipur district namely Deopar (Block- Pusa), Motipur (Block- Tajpur), Aadharpur (Block- Tajpur), Dudhpura (Block- Samastipur) and Dadpur (Block- Samastipur). Five samples each were collected from both cultivated fields and uncultivated fields. Overall, on average 397 colonies from cultivated and 204 colonies from uncultivated fields in both dilution factors 10-4 and 10-5 were isolated and identified. Altogether, the highest percentage contribution was of Trichoderma sp. (28.5 %) in cultivated samples and Penicillium sp. (36 %) in uncultivated samples. All the isolates, Trichoderma sp., Aspergillus sp., Penicillium sp., Fusarium sp., Rhizpous sp. and Mucor sp. were authentically characterized and their percentile contribution statistically analysed. The isolation frequency of species was obtained highest for Penicillium chrysogenum (90 %) and most of the fungal species were designated as moderate and rare in occurrence. In root health bio-assay test conducted in greenhouse, the beans grown in the soil of Deopar and Dadpur in both cultivated and uncultivated soil samples showed best ratings and performance among all the soil samples. In growth promotion study results revealed that overall plant growth promotion was better in cultivated fields. Significant maximum root length (13.0 cm) was observed in cultivated fields of Motipur while in uncultivated fields of Deopar (10.3 cm) and Dadpur (10.3 cm). Maximum shoot length was observed in cultivated fields (62.6 cm) and uncultivated fields in Deopar (55.3 cm). Significant maximum root weight (18.3 g) and (15.6 g) recorded in cultivated and uncultivated fields of Dadpur respectively. However, maximum shoot weight (44.0 g) in cultivated and (42.3 g) in uncultivated fields observed in Aadharpur. In the test for soil physico-chemical properties, Deopar cultivated soil sample showed highest pH (8.2), organic carbon (0.69 %) and organic matter (1.18 %). In population dynamics study, the population of Fusarium oxysporum f. sp. lycopersici was significantly reduced after application of organic amendments. After 60 days, significant highest maximum reduction of Fusarium population was observed in the T-3 (Soil Drenching with Trichoderma asperellum @10 g/l + Chitosan @ 0.1%) and population recorded only (11x105). The lowest PDI (34.40 %) was observed in T-3 (Soil Drenching with Trichoderma asperellum @10 g/l + Chitosan @ 0.1 %) followed by T-2 (Soil Application of FYM + Trichoderma asperellum @ 2% w/w) with PDI (43.30 %). T-3 (Soil Application of Vermicompost @ 2 % w/w) and T-6 (Soil Drenching with Panchgavya @ 30 %) were at par with recorded PDI (46.63 %) and (49.96 %) respectively.EnglishThesis