Cultural and physiological studies of phytophthora parasitica dast. var. macrospora ashby,causing fruit rot of anona squamosa L.

Summary This paper gives an account of some cultural and physiological studies of an isolate ofPhytophthora parasitica Dast. var.macrospora Ashby, the causal agent of fruit rot ofAnona squamosa L. Among the various culture media studied, non-synthetic ones like oat meal agar, corn meal agar, lima-bean agar, carrot extract agar, soya-bean extract agar and steamed rice agar were the best, on which the organism showed marked growth and sporulation. Non-synthetic types were poor in this direction. Regarding the effect of various carbon sources, sucrose, lactose, maltose, raffinose, inulin, dextrin, dulcitol, glycogen, rhamnose and xylose supported growth and sporulation of the organism. Sodium nitrate, ammonium nitrate, magnesium nitrate, potassium nitrate, ammonium lactate and asparagin were the best sources of nitrogen. 6.5 was found to be the best pH for the growth and sporulation of the organism.A portion of Senior Author's M.Sc. Agric. Thesis, University of Poona, India.