Seeds of six sesame (Sesamum indicum L.) cultivar were tested for associated seed mycoflora. Five species of fungi such as, Alternaria sesami, Curvularia lunata, Fusarium oxysporum, Aspergillus flavus and A. niger were found to be associated with these samples and the percentage of seed sample infection and extent of fungal infection ranged from 0-60%. On field seven diseases viz. Alternaria leaf spot (Alternaria sesami), Macrophomina stem rot (Macromophomina phaseolina), Powdery mildew (Oidium sp.), Phytophthora blight (Phytophthora parasitica var. sesami), Cercospora leaf spot (Cercospora sesami), Fusarium wilt (Fusarium oxysporum f.sp.sesami) and Sesame phyllody (Phytoplasma) were occurred during kharif with the incidence/severity ranged from 0.00- 70.97 percent. In respect of disease development, the most important climatic factors favorable in development of Alternaria leaf spot of sesame were the temperature and relative humidity. Scanty rains and long dry spell had more adverse effect on disease development than intermittent rainfall. The PDI was lowest during 35th standard week (2.83%) & increased throughout the cropping period. It was peak during last stage that is 41st standard week (27.71%).