Chemodiagnostic methos EDTA and TTC  tests and physiological parameters electrical conductivity and relative water content are useful to detect the basal stem rot disease in coconut palms, 4 - 14 months before visual symptom expression.  The critical values of these tests  for symptom expression have been fixed.  In coconut trees, root sampling from  any directions at 15 - 30 cm depth is optimum for early detection tests.  Coconut palms without symptoms but showing higher values in diagnostic tests responded well to treatments by registering lesser disease index and higher  nut yield than the treated palms with  external symptoms.