The experiment was carried out during the rabi season of 2019 and 2020 in the net house of Soil Science Division, BARI, Joydebpur, Gazipur. Seeds of groundnut (BARI Groundnut-8) were collected from Oilseed Research Centre, BARI, Gazipur and RARS, Jamalpur. The silted (sandy clay loam) soils were collected from the bank of Turag River at Kodda, Gazipur mixed with cowdung at a 5:1 ratio and was used as the potting media. Each pot (28 cm in diameter and 23 cm in height) was filled with approximately 8-kg soil leaving the upper 3 inches of pot was vacant to facilitate watering. The physical and chemical properties of the soil and cowdung. The soil contained 12 AM (100-1 g soil) spores of indigenous mixed AM fungal species and the experiment was conducted under sterilized soil condition that is done by formaldehyde. Soil pH was measured by a combined glass calomel electrode (Jackson, 1958). Organic carbon was determined by the Wet Oxidation Method (Walkley and Black, 1934). Total N was determined by the modified Kjeldahl method (Jackson, 1962). Calcium, K and Mg were determined by NH4OAc extraction method (Black, 1965). Copper, Fe, Mn and Zn were determined by DTPA extraction followed by AAS reading. Boron was determined by the CaCl2 extraction method. Phosphorus was determined by Modified Olsen method (Neutral + Calcareous soils) according to Olsen et al. (1954). Sulphur was determined by CaH4(PO4)2.H2O extraction followed by turbidimetric turbidity method with BaCl2. Chemical fertilizers were applied as a soil test basis according to the method described in the fertilizer recommendation guide (BARC, 2018). Half of N and all of P, K, S, Mg, Zn, B and Mo applied as basal during final land preparation and the remaining N applied as top dressing at the flowering stage. Pathogen Sclerotium rolfsii and Trichoderma inoculum were collected from Plant Pathology Division, BARI, Gazipur which was grown on non-seed barley. Non-seed barley was collected from Plant Breeding Division, BARI, Gazipur. Pathogen Sclerotium rolfsii along with non-seed barley 70 g was used in Sclerotium treatment per pot. After disease development, pathogen Sclerotia mixed with soil. After that Trichoderma inoculum 60 g was inoculated to each Trichoderma treatment pot. The arbuscular mycorrhizal inoculum was prepared from the roots and rhizosphere soils of Sorghum. Mycorrhizal spp. was originally isolated from different AEZ region, using the wet sieving and decanting method. The single spore was left to multiply for 6 months on sorghum plants using unsterilized soil, collected from the same site, in the net house of Soil Science Division, BARI. Plants were irrigated with tap water as needed. A mixture of infected sorghum root and soil which contained spores was used as mycorrhizal inoculum. The soil-based AM fungal inoculum containing 150 g of rhizosphere soil (approximate 140 spores and 250 ± 20 spores/100 g soil in 2019 and 2020, respectively) and colonized sorghum root fragments with a minimum colonization level was inoculated to each mycorrhizal pot. The mycorrhizal inoculum was first placed in each pot at 3-5 cm depth and was covered with a thin soil layer of 1 cm immediately prior to the seed sowing of groundnut to facilitate fungal colonization of plant roots. The experiment was designed in CRD with eight treatments and four replications. The eight (08) treatments were: T1: Control, T2: Arbuscular Mycorrhizal Fungi, T3: Trichoderma harzianum, T4: Sclerotium rolfsii, T5: AMF+Trichoderma harzianum, T6: Trichoderma harzianum+Sclerotium rolfsii, T7: Sclerotium rolfsii+AMF, T8: AMF+Trichoderma harzianum+Sclerotium rolfsii. Fifteen seeds were sown in each pot at 1 cm soil depth. The treatment was sustained with 06 vigorous seedlings pot-1 and the other seedlings were removed from the pot. Three plants of each were collected for nodulation and colonization data and the rest three plants were kept finally in each pot for yield and yield contributing measurements. The germination test was carried out according to ISTA rules (ISTA, 1976). For each treatment, 100 seeds were put into Petri dishes. The Petri dishes were put on a laboratory table at room temperature (25 ± 2oC). After fifteen days, normal, abnormal and diseased seeds were counted. Germination of groundnut seed in the laboratory table was 90%. Fifteen seeds were sown in each pot. After eight, eleven, fourteen, seventeen- and twenty-days germinated seeds were observed and counted. Germination percentage was obtained as the number of germinated seeds in each pot divided by a total number of seed sown in each pot and multiplied this value by 100. Groundnuts were harvested after maturity and yield parameters were measured. Assessment of spore population was done following the Wet Sieving and Decanting Method (Gerdemann and Nicolson, 1963). All the AM spores were isolated from the extract with the help of fine forceps into a watch glass with a small quantity of water. The extract, with AM spores, was observed under a stereomicroscope and the number of spores was counted. Spore numbers from the three replicates per sample were averaged and the result was expressed as a number per 100 g of dry soil basis. The percentage of AM colonization was estimated by the root slide technique (Read et al., 1976). A root segment was considered as positively infected if it showed mycelium, vesicles and arbuscules or any other combination of these structural characteristics of AM colonization. The presence or absence of colonization in the root pieces was recorded and the percent colonization was calculated as dividing the number of AM positive segments by the total number of segments scored and multiplied this value by 100.