ABSTRACT
The conceptual validity of diagnosis is often a topic of discussion amongst the scientists. They have very rightly argued that diagnosis is done by precept and experience. Diagnosis of disorders and diseases in plants still is largely based on macroscopic and/or microscopic observations. Besides symptoms, the morphological features such as spores, fructifications, or sporophores, which differ from one fungus species to another, form important part of diagnosis program. Besides symptoms, the morphological features such as spores, fructifications, or sporophores, which differ from one fungus species to another, form important part of diagnosis program. Diagnosis of diseases induced by sedentary nematodes is generally easier than that for migratory nematodes. Frequently the combination of symptoms and knowledge of host-range are enough for diagnosis. Use of transmission or scanning electron microscopy in diagnosis of plant diseases is immense. Chromatographic techniques, especially gas chromatography could be successfully employed for identification of plant diseases.
