ABSTRACT
Pathogenicity is the ability of the pathogen to cause disease. Pathogenesis is the chain of events that lead to development of disease in the host or sequence of progress in disease development from the initial contact between the pathogen and its host to the completion of the syndrome. Entry and colonization of pathogen in the host tissues is known as establishment and the infective propagules coming in contact with the host are known as inoculum. The infection process extends from the germination or multiplication of an infective propagule within or on the surface of a potential host to the time the pathogen establishes some form of parasitic relationship with its host. Plant disease cycles represent pathogen biology as a series of interconnected stages of development including dormancy, reproduction, dispersal, and pathogenesis. The invading hypha starts to deteriorate as the cell cytoplasm continues to brown, and death begins to set in.
