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Pest Table 3
Pest Description
IDENTITY: Scientific name: Meloidogyne naasi
Franklin, 1965
 Common name: Barley root-knot nematode

NOTES ON TAXONOMY AND BIOLOGY: Female M. naasi have an oval cuticular perineal pattern without marked lateral lines and with prominent phasmids. This root-knot nematode has sedentary endoparasitic habits. Second-stage juveniles (J2) penetrate host roots where they establish a specialized feeding site (giant cells) in the stele. As J2 develop, they cause root swellings and become swollen females. Females rupture root cortex and some time protrude with the egg masses from the root surface. J2 emerge from the egg masses and migrate in the soil.

GEOGRAPHICAL DISTRIBUTION: This root-knot nematode occurs in temperate regions. Reports include: Belgium, Britain, France, former Yugoslavia, former Soviet Union, Germany Holland, and Italy. In the American continent this species has been reported in Chile and in the Unites States  (California, Illinois, Kansas, Michigan and Oregon) (Allen et al., 1970; Ayton and Dickerson, 1969; Golden and Taylor, 1967; Jensen et al., 1968;Mitchell et al., 1973; Radewald et al., 1966; Radewald et al., 1970; Sikora at al., 1972). It occurs also in New Zealand.

HOSTS: Meloidogyne naasi infects and damages cereals such as barley (Hordeum vulgare), sorghum (Sorghum vulgare), and wheat (Triticum durum and T. vulgare), leguminous crops such as alfalfa (Medicago sativa), alexandrine clover (Trifolium alexandrinum), alsike clover (Trifolium hybridum), garden pea (Pisum sativum), kidney bean (Phaseolus vulgaris), and soybean (Glycine max) and also common chickweed (Stellaria media) and sugarbeet (Beta vulgaris). In host tests conducted in Illinois, the following additional plant species were infected  by a Britsh population introduced from England and three populations from the United States: annual blue grass (Poa annua), buckhorn (Plantago lanceolata), colonial bent grass (Agrostis tenuis), hairy crabgrass (Digitaria sanguinalis), creeping bentgrass (Agrostis palustris), Italian ryegrass (Lolium multiflorum), Kentucky bluegrass  (Poa pratensis) meadow fescue (Festuca pratensis), orchard grass (Dactylis glomerata), oats (Avena sativa), perennial ryegrass (Lolium perenne), redtop (Agrostys alba), rough bluegrass( Poa trivialis), rye (Secale cereale); and wheat (Triticum aestivum).

CROP LOSSES: Consistent damage has been reported on spring barley and on ryegrasses in Europe (Cook and Yeates, 1993; Rivoal and Cook, 1993).

MEANS OF MOVEMENT AND DISPERSAL:  Through root material, soil debris and poorly sanitized bare root propagative plant material.

RATING: (VL) Because this nematode has been reported from five states, and currently there are no regulations to control the interstate movement of this nematode in the USA, this nematode is given a VL priority for regulatory action. However, because of the economic damage reported for M. naasi on spring barley and on ryegrasses, growers and state regulatory agencies should consider excluding this nematode from wheat and rye producing regions where it does not occur.

    Allen, M. W., W. H. Hart, and K. Baghott. 1970. Crop rotation controls barley root-knot nematode at Tulelake. California Agriculture 24:4-5.
    Aytan, S., and O. J. Dickerson.1969. Meloidogyne naasi on sorghum in Kansas. Plant Disease Reporter 53:737.
    Cook, R. and G. W. Yeates. 1993. Nematode pests of grassland and forage crops. Pp.305-350 in K. Evans, D. L. Trudgill, and J. M. Webster eds. Plant parasitic nematodes in temperate agriculture. Wallingford, U. K: CAB International.
    Franklin, M. T. 1973. Meloidogyne naasi. , CIH description of plant parasitic nematodes Set 2, No. 19. St. Albans, UK: Commonwealth Institute of Helminthology.
    Golden, A. M. and D. P. Taylor. 1967. The barley root-knot nematode in Illinois. Plant Disease Reporter 51:974-975.
    Michell, R. E., R.B. Malek, D. P. Taylor, and D. I. Edwards. 1973. Races of the barley root-knot nematode Meloidogyne naasi. Characterization by host preference. Journal of Nematology 5:41-44.
    Michell, R. E., R. B. Malek, D. P. Taylor, and D. I. Edwards. 1973. Races of the barley root-knot nematodes, Meloidogyne naasi. II  Developmental rates. Journal of Nematology 5:44-46.
    Michell, R. E., R. B. Malek, D. P. Taylor, and D.I. Edwards.1973. Races of the barley root-knot nematode Meloidogyne naasi. III Reproduction and pathogenicity on creeping bentgrass. Journal of Nematology 5:47-49.
    Radewald, J. D., L. Ppyatt, F. Shibuya, and H. Humphrey. 1970. Meloidogyne naasi. A parasite of turfgrass in southern California. Plant Disease Reporter 54:940-942.
    Rivoal, R., and R. Cook. 1993. Nematode pests of cereals. Pp.259-303 in K. Evans, D. L. Trudgill, and J. M. Webster eds. Plant parasitic nematodes in temperate agriculture. Wallingford, UK: CAB International.
    Siddiqui, I. A. and D. P. Taylor. 1970. The biology of Meloidogyne naasi. Nematologica 16:133-143.
    Siddiqui, I.A., and D. P. Taylor. 1970. Symptoms and varietal reaction of oats to the Illinois isolate of the barley root-knot nematode, Meloidogyne naasi. Plant Disease Reporter 54:072-975.
    Sikora, R. A., D. P. Taylor, R. B. Malek, and D. I. Edwards. 1972. Interaction of Meloidogyne naasi, Pratylenchus penetrans  and Tylenchorhynchus agri on creeping bentgrass. Journal of Nematology 4: 162-165.