Carrot virus Y

Page last updated: Wednesday, 10 August 2016 - 8:00am

Please note: This content may be out of date and is currently under review.

Carrot virus Y has been found in carrot crops throughout Australia. Infected plants cannot be cured so the best means of control is adopting management practices that minimise the reservoir of infection. Symptoms and management are described.


Carrot virus Y (CarVY) is spread by aphids and causes mild leaf and severe root symptoms in carrots. It seriously diminishes quality if plants are infected at an early growth stage.

CarVY infects some other plants belonging to the same plant family as carrots (Apiaceae) such as anise, chervil, coriander, cumin, dill and parsnip. It does not infect celery, fennel, parsley and several other related herbs.


CarVY has only been detected in Australia. It has been found in carrot crops in New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia. It has been detected at higher levels when carrot crops were grown throughout the year at the same site without a break in production.

Symptoms and losses

In carrot plants, leaf symptoms include chlorotic mottle (irregular small yellow patches), marginal necrosis (browning around leaf edges), and increased subdivision of leaflets giving a feathery appearance with affected plants showing mild stunting (Figure 1).

Two carrot leaves, a healthy leaf on the left compared with a leaf showing the mild mottling and chlorosis characteristic of infection with Carrot virus Y
Figure 1 Healthy carrot leaf (left), and one infected with CarVY showing symptoms of mild mottle and chlorosis (right)

In the roots, the most severe symptoms are seen when infection occurs early – carrot seedlings infected up to six weeks after germination – and include stubby or shortened roots, knobbliness and severe distortion rendering them unmarketable (Figure 2). 

A number of carrots showing symptoms of severe root damage caused by carrot virus Y including blackening and distortion
Figure 2 Carrots with severe root symptoms caused by CarVY

Later infection – carrot plants infected more than six weeks after germination – produces milder symptoms of thinner carrots with only slight distortion, but still with a substantial overall yield loss (around 30%).

In some cases, crops have been abandoned due to large-scale early infection and the severe root symptoms that result.

All commonly grown carrot cultivars are susceptible to CarVY.


Brenda Coutts