Over the past few years, there is a growing trend all over the globe to shift from synthetic to natural products. It is high time now to consider neglected and little known botanicals to cure diseases, which create challenging problems in agriculture and pose real economic and environmental threats. Plant diseases are the major biotic constraints to crop growth and causes variety of damage and significant yield loss. New approaches involving botanical fungicides are considered as alternative to synthetic fungicides as they maintain low mammalian toxicity and biodegradability. Species of genus Cassia have been of special interest due to their good therapeutic value. This book deals with the evaluation the antifungal activity of Cassia spp.against major phytopathogenic fungi, followed by identification and characterization of its active ingredient(s).This study suggests, Cassia laevigata has potent antifungal activity,which may be used as a new cost effective botanical fungicide. This book, therefore,useful to professionals in agriculture, plant pathology and plant biochemistry.