Citrus exocortis is a disease of
citrus
''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is native to ...
plants, caused by the Citrus exocortis
viroid
Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economi ...
(CEVd). It can cause stunted growth and reduced yields in affected plants. The disease is also sometimes called "scalybutt". CEVd can also infect tomato plants. The resulting disease is sometimes called "tomato bunchy top disease."
Symptoms
Other symptoms include leaf epinasty, stunting, and necrosis of the leaf midvein. Affected trees will show
rootstock
A rootstock is part of a plant, often an underground part, from which new above-ground growth can be produced. It could also be described as a stem with a well developed root system, to which a bud from another plant is grafted. It can refer to a ...
"shelling" where the bark peels off of the rootstock the lower tree that the main orange
cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
was
grafted
Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...
onto. Generally
trifoliate orange
The trifoliate orange, ''Citrus trifoliata'' or ''Poncirus trifoliata'', is a member of the family Rutaceae. Whether the trifoliate oranges should be considered to belong to their own genus, ''Poncirus'', or be included in the genus ''Citrus'' is ...
rootstocks and their hybrids are susceptible.
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.
See also
*
List of citrus diseases
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College, an undergraduate division of the Jewish Theological Seminary of America
* SC Germania List, German rugby union ...
References
Viral citrus diseases
Viroids
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