The experiment was carried out during rabi season from December 2019 to April 2020 in the net house of Soil Science Division, BARI, Joydebpur, Gazipur (230 59'378'' N latitude, 900 24'886'' E longitude and 8.4 m elevation). Seeds of groundnut (BARI Chinabadam-8) were collected from RARS, Jamalpur. The silted (sandy clay loam) soils were collected from the bank of Turag river at Kodda, Gazipur mixed with cowdung at 5:1 ratio and was used as the potting media. Each pot (25 cm in diameter and 21 cm in height) was filled with approximately 6 kg soil leaving the upper 3 inches of pot was vacant to facilitate watering. The pH of cowdung was 6.7 and the nutrient contents were: organic matter 14.1%, N 0.8%, P 1.26%, K 0.88%, Ca 1.55%, Mg 0.82%, S 0.62%, Fe 0.25% and Mn 0.112%. The soil contained 12 AM (100-1 g soil) spores of indigenous mixed AM fungal species and the experiment was conducted under sterilized soil conditions. 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 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 CaCl2 extraction method. Phosphorus was determined by the 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 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 a top dressing at the flowering stage. Pathogen Sclerotium rolfsii were collected from Plant Pathology Division, BARI, Gazipur which was grown on non seed barley. Non-seed barley collected from Plant Breeding Division, BARI, Gazipur. Pathogen Sclerotium rolfsii along with non seed barley 50 g was used per Sclerotium treatment pot. After disease development, pathogen sclerotia mixed with soil. Rhizobium strain BARI RAh-801 was collected from Soil Microbiology Division, BARI, Gazipur and mixed properly with the seed before sowing. The arbuscular mycorrhizal inoculum was prepared from the roots and rhizosphere soils of Sorghum. Mycorrhizal species was originally isolated from different AEZ region, using the wet sieving and decanting method. The spores were 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 approximately 252 spores 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 RCBD with eight treatments and four replications. Fifteen seeds were sown in each pot at 1 cm soil depth. The eight (08) treatments were: T1: Arbuscular mycorrhizal fungi (AMF), T2: Rhizobium (R), T3: AMF+Rhizobium, T4: Sclerotium rolfsii, T5: Sclerotium rolfsii+AMF, T6: Sclerotium rolfsii+Rhizobium, T7: Sclerotium rolfsii+AMF+Rhizobium and T8: Control. 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 modulation 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 95%. Fifteen seeds were sown in each pot. After 10, 13, 16, 19- and 22-days germinated seeds were observed and counted. Germination percentage was obtained as the number of germinated seeds in each pot divided by the total number of seeds 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. 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. 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 a total number of segments scored and multiplied this value by 100. Data were statistically analyzed using Analysis of Variance (ANOVA) following Statistix 10 package.