Armillaria root diseases of diverse trees in wide-spread global regions

Armillaria root disease, caused by diverse species from the Agaricomycete genus Armillaria s.l. (including the closely related genus Desarmillaria), is a primary cause of mortality and growth loss of widely ranging horticultural, urban, and forest trees and shrubs in diverse boreal, temperate, and tropical/subtropical regions where woody plants grow around the world. Whether behaving as a pathogen or saprotroph, Armillaria causes white rot, in which the three main polymeric constituents of woody tissues (lignin, cellulose, hemicellulose) are degraded during the decay process. This chapter provides a compendium of Armillaria root diseases on diverse trees in wide-spread global regions and includes topics such as species identification, disease spread, geographical distribution, ecology, infection biology, and disease management.