Selected Pacific Northwest Rangeland and Weed Plants as Hosts of Pratylenchus neglectus and P. thornei.

Eighteen rangeland plants and 16 weed species were assayed in the greenhouse for efficiency as hosts of Pratylenchus neglectus and P. thornei. Hosting ability ratings were assigned using the ratio of final versus initial nematode density and by comparing the final nematode density to that of susceptible wheat controls. Good hosts of both Pratylenchus spp. included thickspike bluegrass 'Critana', smooth brome 'Manchar', seven wheatgrasses, and jointed goatgrass. Good hosts of P. neglectus but not P. thornei included two hairy vetches, western wheatgrass 'Rosana', big bluegrass 'Sherman', tall wheatgrass 'Alkar', green foxtail, kochia, large crabgrass, palmer amaranth, redroot pigweed, tumble mustard, and wild oat. Good hosts of P. thornei but not P. neglectus included hard fescue 'Durar', sheep fescue 'Blacksheep', downy brome, and rattail fescue. Poor or minor hosts of both Pratylenchus spp. included two alfalfas, dandelion, horseweed, lambsquarters, prostrate spurge, and Russian thistle. These assays will provide guidance for transitioning rangeland into crop production and for understanding the role of weeds on densities of Pratylenchus spp. in wheat-production systems.