plum pox (sharka disease) A disease of plum and related trees whose symptoms are variable according to the plant species, but which usually include the appearance of pale or dark rings or spots on leaves and fruit. Plum pox is a disease of considerable economic importance, and is a notifiable disease in Britain. It is caused by a virus and is transmitted by aphids.

plum pox(sharka disease) A disease of plum and related trees, the symptoms of which vary according to the species affected, but which usually include the appearance of pale or dark rings or spots on leaves and fruit. Plum pox is a disease of considerable economic importance and is a notifiable disease in Britain. It is caused by a virus and transmitted by aphids.