The hop stunt viroid (abbreviated HSVd) is a viroid species that infects the common hop plant,[1] citrus plants, grapevines, cucumber, and several Prunus species such as almond, apricot, plum, and peach.[2][3] It is asymptomatic or latent in most host plants, but in some hosts it can cause stunting and other symphtoms. A study of HSVd-infected hops in the USA showed that the severity of yield reduction was highly dependent on the infected hop cultivar.[4]
HSVd is a member of the Pospiviroidae family and the Hostuviroid genus.
There are quite a few different sub-species of the hop stunt viroid.