Carrot Pests And Diseases

Carrot fly – Also commonly known as carrot root flies, are one of the worst pests that can affect your carrots. The damage can be widespread across your carrot crop, and it is actually the carrot fly larvae that cause the damage by eating into the crop.

Spotting the problem is relatively easy as early warning signs are discoloured leaves and holes appearing in the top of the carrots. The holes caused by the larvae can often turn a rusty brown and this is due to a fungal disease known as carrot or parsnip canker. Of note is that carrot flies also effect parsnips, parsley, celeriac and celery plants as well.

The flies themselves are around 5mm long, with orange legs, a black body and a red to brown head. They are noticeable in that they cannot actually fly that well. However it is the subsequent larvae that cause the main problem to the crop.

The larvae are creamy yellow and around 1cm in length. The larvae cause a lot of damage as they tunnel through the soil attacking any roots they find. Unfortunately there are no pesticide treatments available, so the only recourse is to cover them with a fine net to keep the flies away.

Aphids – These look like small clusters of spots and can vary in colour from white to black, and brown to red. These are a common garden pest and whilst they can come back with annoying frequency, they can be removed with a strong jet of water or the application of mild soapy water. The best way to get rid of them is to introduce natural predators such as ladybirds into the environment where the carrots are growing. Aphids are rarer on carrots than other plants as they do not tend to like the exposed conditions of wind and rain that most vegetable beds experience. They can be treated with pesticide sprays, and it is better to spray the crop early as with all things prevention is often easier than a cure.

Powdery Mildew – This disease affects a wide range of garden plants but if untreated it can spread and actually make plants inedible. It takes the form of a powdery white substance that forms on the leaves, it looks unsightly, and can cause new growth to die, with early signs being leaves becoming distorted and they may also show dark brown or bright yellow spots.

Powdrey mildew gets its name from fungal strands throwing out hundreds of spores that appear to form a powder on the carrots leaves. It thrives on dry conditions, on plants spaced too close together in low light conditions. Therefore to avoid it occurring on your crop then ensure the plants are well watered, and well spaced apart. Powdery mildew can be treated with pesticides containing myclobutanil, penconazole and flutriafol, or a light sprinkling of sulphur dust.

Cutworms – If you have ever had the tops of plants disappear overnight then the chances are it is a cutworm that has done the damage, and they affect carrots just as much as other vegetables. They can be a pain to treat as they are spread by a noctural moth. The moth lays its eggs at night in batches of 30 to 50 on both carrot stems and leaves, it is the larvae that the eggs develop into that are the cutworms. The cutworms can be hard to treat as like the moths that lay them they only appear at night, however they are around 2-4cm in length so a trip outside at night with a torch is often a solution.

See also How To Grow Carrots

By Richard Allen -