Frequently asked questions about potato nematodes

Frequently asked questions and answers

Have a question about potato nematodes? Learn ways to combat potato nematodes in your fields and more by viewing our most frequently asked questions and answers below.

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A potato is tuber, the swollen part (usually the end) of the stolon. A stolon is an underground stem. Swelling of the tuber is primarily due to the accumulation of starch.


Root knot nematodes            

  • Meloidogyne chitwoodi (Columbia root knot)
  • Meloidogyne hapla (Northern root knot)
  • Meloidogyne incognita (Southern root knot)
  • Meloidogyne javanica

Potato cyst nematodes

  • Globodera pallida (Pale cyst nematode)
  • Globodera rostochiensis (Golden Nematode)

Stubby root nematodes

  • Nanidorus minor (Paratrichodorus or Trichodorus spp.)

Root lesion nematodes

  • Pratylenchus neglectus
  • Pratylenchus penetrans

Potato rot nematodes

  • Ditylenchus destructor

Sting nematodes

  • Belonolaimus longicaudatus

Injury to both above and below ground plant parts affects both tuber yield and tuber quality.

Above ground symptoms:

  • Stunting of plants
  • Yellowing of leaves
  • Die back of plants
  • Premature wilting
  • Patches of non-uniform growth

Below ground symptoms:

  • Sometimes more distinctive
  • Decreased root mass
  • Galls
  • Stubby roots
  • Blackened lesions
  • Cysts (yellow, white, or tan)

Plant-parasitic nematodes spread through infested soil or tubers.

Detection and diagnostics: determine which nematode is present within a field.

Population level: is it economically damaging? Some nematodes have zero tolerance.

Control: select a profitable management strategy.

No single control method provides perfect protection for a crop, so you may need several management strategies:

  • Avoidance
  • Cultural (clean seed, rotation)
  • Variety selection – e.g. is planting a resistant variety an option?
  • Nematicide – soil fumigant, seed treatment, in furrow
  • Quarantine for some regulated nematodes


To best plan your management strategy, testing your field annually is recommended to find out the species and level of nematodes present in a field.

Regardless of the type of plant-parasitic nematode found in a field, the most common management strategy is:

  • Preplant fumigation
    • 1,3-dichloropropene
    • Metam sodium
  • Post plant application
    • Oxamyl

Nematicides are expensive and account for about 10% of total production cost (biggest of all inputs). Many nematicides are no longer available, are being phased out, and are costly.

Prevent introduction

  • Avoid contaminated soil movement
  • Plant certified seed
  • Properly dispose of culls and waste soil

Crop Rotation

  • Species dependent
  • Multiple cropping strategies
  • Extended fallow
  • Challenging when a nematode has a wide host range

Quarantine (official regulatory)

  • Potato cyst nematodes