Abstract
This chapter describes the general principles of disease management that apply to all pathogens, followed by a detailed description of the major pathogens, which fall into 4 broad categories, i.e. fungi/oomycetes, bacteria/phytoplasma, viruses and nematodes. The most important diseases of cut flowers, their causal microorganisms, symptoms and signs, epidemiology and management practices are addressed and organized by the primary tissues affected.