Chapter 26 – Other Cocadviroids

Citrus bark cracking viroid (CBCVd) and the hop latent viroid (HLVd) are members of the genus Cocadviroid of the family Pospiviroidae. Both viroids are globally distributed. CBCVd does not induce any significant disease of citrus but incites bark cracking of sensitive citrus rootstock species and has been associated with a severe disease of hops. HLVd does not induce any acute hop symptoms but causes physiological changes with negative yield and quality effects. Both viroids are readily transmitted by mechanical means, detected by molecular assays, and eliminated from the germplasm using meristematic tissue culture. Comprehensive programs that include the use of viroid-tested propagative materials and sanitary measures are required for the management of CBCVd and HLVd.