blight

A plant disease in which leaf damage is sudden and serious. Many pathogens can cause blight-type symptoms when conditions are suitable but only a few cause such devastating symptoms on a regular basis: these include the term 'blight' in their common names. Examples include late and early blight of potatoes (caused by the fungi Phytophthora infestans and Alternaria solani respectively), and *fireblight of pears (caused by the bacterium Envinia amylovora).