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Bacterial Leaf Blight

Xanthomonas hortorum pv. carotae

Bacterial Leaf Blight, Bacterial Leaf Blight of Carrot, Root Scab of Carrot

Bacterial Leaf Blight is a common plant disorder caused by a bacterium specifically affecting carrot. It spreads by water and is problematic in gardens exposed to frequent rainfall. In agriculture, it can be encouraged by too much sprinkler irrigation.
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Brown spots with yellow outlines on the tips of leaves. Leaf tips dry out, curled, or even distorted.


Initially, small yellow spots appear on carrot leaves.
Spots grow larger and turn black.
Leaves dry out and become shrivelled.
Leaf distortion or curling.
Stalks of leaves may ooze yellow-brown liquid.
Umbels eventually develop blight.
Seeds can be infected.

Chemical treatment

Some copper bactericides can slow the spread of the disease, but it's not curable. If any product is purchased or used, check that it's authorised for use in your country or state. Always take care to read instructions and make sure that your edible crop is listed on instructions. Flowering plants shouldn't be sprayed.


Make sure the seed you use is from a reputable source or business. You can bathe infested seeds in hot water for approx 25 minutes (above 52 degrees). Practise crop rotation. Keeping good plant and tool hygiene. Good pest control.

Affected plants

A bunch of orange Daucus carota subsp. sativus carrots


Daucus carota ssp. sativus

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