Introduction to infectious plant diseases, disease triangle, cycle of disease , introduce the student to plant pathology which is the study of disease in plants and this implies the growth, appearance and behavior., some examples for plant infectious diseases Pam ping off and seedling blights, root and foot rots, wilts, powdery mildews, powdery mildews, rusts, smut, blights, anthracnose, leaf spots, leaf curl witches' broom, club root, galls, canker and scab, mosaics and yellows, post-harvest diseases, diseases control.