Curly top

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.

The most common plants to carry the curly virus are beets, tomatoes, spinach, peppers, beans, potatoes, cucurbits, many ornamentals, and weeds such as Russian thistle (tumbleweed) and mustard. These are not the only plants to carry this, in fact, a total of 44 plant families and 300 species are susceptible to it. Sugar beets are the most common carriers of the disease, for which the alternative name of the disease, beet curly top virus (BCTV), is derived from.

Curly top virus is transmitted by the sugar beet leafhopper (Curculifer tennelus) throughout arid and semi-arid locations.

...
Wikipedia