Curly top virus
A leafhopper-spread virus that makes leaves roll, thicken and turn yellow, and stunts beet, tomato, pepper and bean plants.
Also known as: Beet curly top, Curly top
Symptoms and identification
Leaves curl upwards, become thick, leathery and brittle, and turn yellow or purple along the veins. Plants stay stunted and often collapse in the heat. Fruit on infected tomato plants ripen early and are small and dull.
Causes
The virus is carried from wild plants and weeds to crops by beet leafhoppers feeding on the leaves. Outbreaks are common in dry, warm regions in early summer.
Organic treatment
There is no cure. Remove and bin infected plants before the virus spreads further, and cover seedlings with netting.
Prevention
Remove weeds that host leafhoppers and the virus, protect young plants with fine insect netting, and plant resistant varieties where available. Shade and mulch can lower the pressure.
Chemical treatment (use with care)
No chemical cures a virus. Insecticides aimed at leafhoppers rarely prevent spread because infection happens in minutes.