Citrus exocortis

Citrus exocortis is a disease of citrus plants, caused by the Citrus exocortis viroid (CEVd, Pospiviroid exocortiscitri). It can cause stunted growth and reduced yields in affected plants. The disease is also sometimes called "scalybutt".^[1] CEVd can also infect tomato plants. The resulting disease is sometimes called "tomato bunchy top disease".^[2][3]

Citrus exocortis viroid
Virus classification
Informal group:	Subviral agents
Informal group:	Viroids
Family:	Pospiviroidae
Genus:	Pospiviroid
Species:	Citrus exocortis viroid

Symptoms

Other symptoms include leaf epinasty, stunting, and necrosis of the leaf midvein. Affected trees will show rootstock "shelling" where the bark peels off of the rootstock – the lower tree that the main orange cultivar was grafted onto. Generally trifoliate orange rootstocks and their hybrids are susceptible.^[4]

Management

Infected trees should be culled from the orchard. When pruning in infected orchards, tools must be vigorously bleached between cuts to prevent cross-contamination and the spread of infections. Heat does not kill the viroid.^[4]

See also

• List of citrus diseases