Pathogens are grouped taxonomically into related groups. It is helpful to know the type of pathogen in order to prescribe a control. Specific diseases are discussed in the chapters dealing with the plant. Plant disease names are often very colorful and descriptive, as in fireblight, black knot and clubroot. Many disease names indicate something about the appearance of the symptoms.
Fungi often develop into colonies, like bread mold.
Some fungi develop into large structures, such as mushrooms. Fungi spread by spores carried by wind, water or animals. They enter host plants directly or through natural openings or wounds. They cause damage by producing substances that change or destroy plant tissues. Common fungal diseases include powdery mildew, rust, leaf spot, blight, root and crown rots, damping-off, smut, anthracnose, and vascular wilts.