Abstract

Almond is affected by several phytoplasma diseases but almond witches' broom (AlmWB) is the most destructive one. The disease spread rapidly, killed about a hundred thousands trees in recent years. Association of phytoplasma with AlmWB disease thatbelonged to the pigeon pea witches’-broom (PPWB) group has been established and the name ‘Candidatus Phytoplasma phoenicium’ (16sIX-B) is proposed for it. The phytoplasma was graft-transmissible to almond, plum and peach seedlings. A specific PCR test was developed to distinguish the almond phytoplasma from others in the PPWB group. The specific PCR will be particularly useful for identification of both the insect vector(s) and reservoir plant(s) of the almond phytoplasma. For the moment only very few data is available on the extent of the disease, on its biology and epidemiology. However, this disease could represent a serious threat for almond-producing countries.

Key words: Almond witches broom, phytoplasma, peach, almond.