
During the survey of plant disease 2013 and 2014, powdery mildew disease was found on sandalwood. Pseudoidium santalacearum (U.braun and Hosag.) U.Braun and R.T.A. Cook. was identified as the causal agent of a powdery mildew disease occurring on sandalwood Santalum album L. in Mandsaur and Indore districts of Madhya Pradesh India on the basis of symptoms, morphological characters and host range. This disease was observed in leaf of sandalwood tree located in the boundary area of Panchayat bhawan Mandsaur and Agriculture College campus, Indore. Floury small, circular white patches were seen on both sides of leaf surface in initial stage and these spots increased in size and spread all over the surface of leaves. The mycelium of Pseudoidium santalacearum are epiphytic, amphiphyllous, thick coating, hyaline, conidia formed singly (not in chain). This disease was noticed for the first time in Madhya Pradesh, India. The pathogenecity was confirmed by dusting of conidia on healthy leaves.