Abstract
Characteristics of root development of evergreen azaleas were evaluated quantitatively. ‘Oomurasaki’ and ‘Shiro-ryukyu’, which are vigorous in growth and often used for landscaping, had a greater root length density and developed root systems penetrating deep soil layers. Most azaleas developed greater root length density in a moderately wet soil moisture area than in a wet soil area. However, R. indicum which distributes in rocky riverside areas, demonstrated a greater root length density only in wet soil area and the root development was especially concentrated in the surface soil layer. Thus, differences in root development system and root adaptation to moisture environments observed between species and/or cultivars, would have originated from the adaptation of each species to the natural environment.
