Lesion Nematode: Identification, Damage & Natural Control

Lesion Nematode

Lesion nematodes (Pratylenchus spp.) are migratory root parasites that burrow through root tissue, leaving dark lesions and entry points for secondary rots across cereals, fruit, vegetables and many crops. In Vegalab programs they are managed at planting with Nematode Control plus rotation and soil-health support.

Common crops affected

Cereals
Corn
Tree fruit
Potato

What is it?

Lesion nematodes are migratory endoparasites — they move in and out of roots as they feed, destroying root cells along the way. The wounds they create are gateways for fungi and bacteria, so damage is often a nematode-plus-rot complex.

How to identify it

Dark, sunken lesions and streaks on roots; root browning and dieback of fine roots.
Patchy stunting, reduced vigour and drought-like stress in affected areas.
Replant problems in orchards (a classic lesion-nematode symptom).
Confirmation via soil/root assay — lesion nematodes are inside and around roots.

Life cycle & spread

All mobile stages can infect; they migrate through soil and roots, reproduce within the season, and survive in roots and debris between crops. Multiple generations occur in warm conditions.

Conditions that favour it

Continuous susceptible cropping, orchard replant sites, and warm soils favour build-up; cool-season species damage cereals.

Damage and how it spreads

Reduces root mass and function and opens roots to rot pathogens, cutting yield and causing orchard replant failure. The combined nematode-plus-rot effect can be severe.

Monitoring & scouting

Soil/root assays in problem areas; check fine roots for lesions; flag orchard replant sites for at-plant treatment.

How to control it

Treat at planting, rotate where possible, manage the secondary-rot complex with sanitation and soil health, and support vigorous root regrowth.

Role	Product	Use
Primary control	Nematode Control
Also apply	Root Boost

Preventing it next season

Rotation, clean planting sites, at-plant treatment (especially orchard replant), and root-zone health support.

Not sure this is what's affecting your crop? Ask an agronomist about your crop →

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Frequently asked questions

What controls lesion nematode naturally?

Vegalab Nematode Control applied at planting in-furrow or through drip.

Why are lesion nematodes a 'complex' problem?

Their feeding wounds let fungi and bacteria into roots, so damage is often nematode plus secondary rot.

What is orchard replant disease?

Poor growth of young trees on old orchard sites — lesion nematodes are a common contributor; treat at planting.

Which crops are affected?

Cereals, corn, potato, tree fruit, vines and vegetables.

How do I confirm it?

A soil and root assay, since lesion nematodes live in and around the roots.