The difficulty in the production of agricultural and horticultural crops due to plant diseases is decreasing the quality and quantity of crops products. It is mainly due to coming out of new plant diseases agents in India and elsewhere in the world. For better understanding of the different aspects of the plant diseases, the acceptance of proper and relevant experimental methodology is most significance. It is often realised that our education in plant pathology is commonly pathetic on the practical side than in theory. One of the key factors for this shortcoming is the lack of availability of practical manuals for the students undergoing with undergraduate and post graduate courses of plant pathology. The awareness of appropriate plant disease diagnosis, exact cause of the disease and understanding the dynamics of disease etc becomes very important to ultimately derive measures to control the plant diseases. We belief that; this practical manual will serve as the useful resource and guide to all concerned in agriculture, horticulture, forests and in resolving plant disease diagnosis and disease management. Students will get large number of methods of plant pathological experiments in this practical manual. Some of the methods are as such enjoy the status of ?ready to use" in the laboratory. A much greater number of such methods have been included in this practical manual and those which are given for the first time in such category of manual are also be interested such as a chapter on culture collection centres, name of journals, magazine, books and exercise on formulation of fungicides their application.