• Band of dark brown necrosis around the crown and horizontal brown canker-like lesions mostly on the crown and upper roots
• Small pits subsequently developed beneath the lesions, that enlarged into sunken brown crater lines with a white, flocculent mycelium produced under high humidity

Bitterness:

• Carrots can develop off-flavours or bitterness in cool storage. The cause of these off-flavours is the production of compounds in carrots called isocoumarins. Isocoumarins develop when carrots are exposed to ethylene.
• Ethylene is a gas produced naturally by many fruits and vegetables, such as apples, bananas and tomatoes during ripening.
• Carrots can be stored in sealed plastic bags in domestic refrigerators containing ethylene producing fruit.

Phenolic browning:

• Phenolic browning (or surface browning) is seen as a browning or discoloration of the surface of carrot.
• It can develop when carrots are washed and stored in cool     rooms for long periods before packing.
•  Abrasion caused by mechanical washing often removes the epidermal layer (outer skin), exposing the carrot tissue to oxidation of phenolic compounds, which turn brown, or black in severe cases.
• Phenolic browning can be confused with ‘5 o’clock shadow’ or boron deficiency of carrots. Phenolic browning can be confused with ‘5 o’clock shadow’ or boron deficiency of carrots.
• The latter is seen as many small brown spots under the skin, causing the root to look dull.

Identification of pathogen:

• Bacteria is gram –ve, motile with large peritrichous flagella

Mode of spread and survival:

• Soil - source of primary inoculum
• Survive in decaying refuse and enter the root principally through cultivation wounds, harvest bruises, freezing injury, and insect openings
• Flies- Hylemus cillicrura, H. brassicae carry the bacteria in their intestinal tracts

• Rapid removal of field heat.
• Application of  Dowicide (Ophenylphenol) @ 98 g/L
• 6-methoxy mellen increase resistance
• Cholorothalonil – Seed and soil application
• 8 years rotation with non host crop
• Using disease free seed.
• Bacillus subtilis & T.viride application