Beet curly top

Beet curly top is a destructive viral disease caused by viruses within the genus Curtovirus (family Geminiviridae). The pathogen invades the plant's phloem, causing systemic infection that disrupts the transport of nutrients, which leads to severe stunting and often the death of the infected host plant.

The disease is exclusively transmitted by the beet leafhopper (Circulifer tenellus). Once a leafhopper feeds on an infected plant, it becomes a vector for the rest of its life, effectively spreading the virus to healthy plants as it feeds. The virus is not soil-borne, seed-borne, or transmitted through simple contact between plants.

The host range is exceptionally broad, affecting numerous economically important agricultural crops. Among the most susceptible are watermelon, common beans, and garden spinach. Other major hosts include sugar beets, tomatoes, peppers, and various cucurbits, often resulting in significant yield losses when environmental conditions favor the vector population.

Common field symptoms include:

• inward curling of leaves and thickening of leaf tissues;
• yellowing or reddening of leaves;
• severe stunting or "dwarfing" of the entire plant;
• abnormal branching resulting in a bushy appearance;
• necrosis of the vascular system and root rot.

Managing Beet curly top is challenging because there are no curative treatments once a plant is infected. Prevention is the primary control strategy: this includes controlling weed hosts in and around fields to remove the virus reservoir, using resistant or tolerant cultivars, and applying systemic insecticides to manage leafhopper populations during the early stages of plant development. Planting dates should also be adjusted to avoid peak migration periods of the vector.