A newly recorded witches' broom disease was observed on Kanehirai azalea (Rhododendron Kanehirai Wilson) in Shin-Shan Nursery, Taipei. Infected plants showed severe witches' broom symptom and resulted in the death of the diseased branches and sometime the whole plant. Electron microscopic examination of ultrathin sections revealed the presence of mycoplasmalike organisms (MLOs) in the sieve tubes and companion cells of infected tissues. The size of the MLOs ranged from 110-620 nm and averaged 220 nm. None of the cultivated azaleas (Rhododendron pulchrum Sweet) grown near the Kanehirai azalea showed any symptoms. This is the first report of Kanenhirai azalea witches' broom disease and its association with MLOs.
