Carrot

Carrot fly

What you will see

Rust-brown scars and tunnels in the roots; slender creamy-yellow larvae up to 9 mm inside.

The source says: carrot is a susceptible vegetable; the roots can become inedible.

How to protect

1. Prevention

   • Sow thinly so you do not have to thin; thinning out seedlings attracts females with the scent.
   • Sow after mid-May (avoiding the 1st generation) and harvest before the end of August (avoiding the 2nd generation).
   • Cover crops with fine mesh and rotate crops; full cover is more effective than a barrier.
   • Choose less susceptible varieties (e.g. 'Fly Away', 'Maestro', 'Resistafly', 'Sytan').
2. Biological spring and summer, when larvae hatchA mixture of pathogenic nematodes watered into the soil against young larvae (Steinernema feltiae in spring, S. carpocapsae in summer).

Splitting of root vegetables

What you will see

Roots split lengthwise, usually from the top, sometimes down to the core. Soft rot can enter through the cracks; damage is often only visible at harvest.

The source says: carrots are the most prone to splitting.

How to protect

1. Prevention

   • Water evenly, not alternating between dry and wet. After drought and heavy rain, roots take up water quickly and split.
   • In dry weather, water deeply about once every two weeks, and once a week as the roots approach harvest; especially on sandy and chalky soil.
   • Improve the soil with well-rotted organic matter; do not put fresh manure under carrots.
   • Excess nitrogen and temperature swings can contribute; frost can burst some roots.
   • If the problem recurs, choose varieties resistant to splitting; lift less frost-hardy roots before the first autumn frosts.
2. By hand as soon as it is foundRemove split roots straight away. Use the healthy part quickly before it starts to rot, and clean mud out of the cracks thoroughly. There is no chemical treatment.

Wireworms

What you will see

Wiry beetle larvae bore holes in the root.

How to protect

1. Prevention

   • Tolerate a few wireworms; in grass and turf they are usually harmless.
   • The population usually falls within two years after turf is dug up.
2. By hand when digging overCultivating the soil exposes the larvae to birds.
3. Biological April to SeptemberNematodes against wireworms, watered into moist soil at 12–20 °C (April to September).

Slugs and snails

What you will see

Irregular holes in soft leaves and young shoots and slime trails; they feed at night.

How to protect

1. Prevention

   • Water in the morning, not the evening (evening watering helps them move around).
   • Encourage their natural enemies: birds, hedgehogs, toads, ground beetles.
2. By hand evening, after rainPick them off by hand on damp evenings and take them far away. Traps: hollowed-out citrus halves placed cut side down, or sunken containers of beer; check in the morning.
3. Biological when the soil is warm and moistSlug-specific nematodes (from a biological control supplier) are watered into the soil.
4. Chemical — only when nothing else helps according to the product labelLast resort only: a product authorised in your country against slugs and snails. Try non-chemical methods first.

Reed planthopper (vector of SBR and stolbur)

What you will see

It transmits the bacteria SBR and stolbur: leaves change colour and wilt, taste and quality change, storage roots become soft and rubbery. Some affected plants show no symptoms. Nymphs develop in the soil.

How to protect

1. Prevention

   • Keep to crop rotation.
   • Use crop nets.
   • Bare fallow can reduce pest pressure.
2. Chemical — only when nothing else helps according to the regional plant protection warning serviceIn Bavaria only emergency authorisations for spraying against the planthopper were granted for the 2026 season; protection strategies and the course of the infection are still unclear. Use only a product authorised in your country against planthoppers on the crop in question.