Meloidogyne naasi




Rev 12/11/2019

Barley root-knot nematode Classification Hosts
Morphology and Anatomy Life Cycle
Return to Meloidogyne Menu Economic Importance Damage
Distribution Management
Return to Heteroderidae Menu Feeding  References
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        Meloidogyne naasi  Franklin, 1965

Barley root-knot nematode.

The specific name is derived from the initials of the UK National Agricultural Advisory Service.

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Morphology and Anatomy:


A,B,C=male; D,E,F=female; G,H,I,J,K=second-stage juvenile

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

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Temperate areas of the United States and Europe. Originally described from field crops (cereals, grasses, sugarbeet) in England and Wales.

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Economic Importance:

B-rated pest in California Nematode Pest Rating System.

In California, this species can cause yield losses of 50-75% in barley grown under continuous cropping in the Tulelake innermountain region. 


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 Feeding site establishment and development typical of genus.

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Grasses, cereals, and weeds. 

For an extensive host range list for this species, click


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Life Cycle:

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click If species level data are not available, click for genus level parameters


Egg hatch in water is very limited unless eggs have been chilled by storage below 5C for 1 to 7 weeks  (Franklin et al, 1971). 

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Galls are generally cylindrical, spindle-shaped, or hooked. 

Feeding causes necrosis, hyperplasia, and hypertrophy of cortex; also causes disorganization of xylem elements. 


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Crop rotation can be effective in California (1 year fallow or 2 seasons of potatoes increased barley yield - Allen, 1970).

Host Plant Resistance, Non-hosts and Crop Rotation alternatives:

For plants reported to have some level of resistance to this species, click


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CIH Descriptions of Plant-parasitic Nematodes, Set 2, No. 19 (1973)

Franklin, M.T., S.A. Clarke and J.A. Course. 1971. Nematologica 17:575-590.

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Copyright © 1999 by Howard Ferris.
Revised: December 11, 2019.