Curly top is the name of a number of viral plant diseases, many of which affect food crops. They are often caused by curtoviruses (genus Curtovirus), members of the virus family Geminiviridae.
Curly top is characterized by stunting of the plant and deformation of leaves and fruit. The petioles and blades of the leaves curl, twist, and become discolored.
Beet curly top virus causes curly top disease in beets and is carried by the beet leafhopper. The term curly top virus often refers to this specific virus. It can also cause curly top in tomatoes, beans, cucurbits, and other crops.
Curly top disease in spinach can be caused by the beet curly top virus, the pepper curly top virus, or the recently described spinach curly top virus.
Other curly top curtoviruses include beet severe curly top virus, beet mild curly top virus, and horseradish curly top virus. The newly discovered turnip curly top virus may also be a species of curtovirus.
