"From the Foreword. . . . . .The coverage is comprehensive and the subject has been dealt with in an authoritative manner. . . .We owe a deep debt of gratitude to Dr. Narayanasamy for this labour of love."---M. S. Swaminathan Chairman, MS Swaminathan Research Foundation Holder of the UNESCO Chair of Eco-technology, Chennai, India Praise for the previous edition. . .". . .a valuable overview on recent detection and typing methods. . ..an important aid for familiarization and extension of one's knowledge."---Journal of Phytopathology (1999)". . .a diversity of information and techniques in a compact and handy format."---Agronomie (1999)". . .a valuable book."---Journal of Plant Physiology (1998)