In greenhouse experiments at 26 3C, soil texture affected the host-parasite relationship of 4 nematode species on crested wheatgrasses, Russian wildrye, intermediate wheatgrass, and Snake River wheatgrass. Pratylenchus neglectus was least affected by soil texture but was the most pathogenic of the species examined. Xiphinema americanum was most affected by soil texture and was the least pathogenic, reducing (P 0.05) plant growth only in sandy soil. Pratylenchus neglectus reduced plant growth in clay, clay-sand and sandy soils, whereas Merlinius brevidens, and Tylenchorhynchus acutus reduced (P 0.05) plant growth in clay-sand and sandy loam soils. The pathogenicity and reproduction of the 3 nematode species were greatest in sandy loam soil. Reproduction was highest for P. neglectus, while X. americanum failed to increase in any soil texture. 'Hycrest crested wheatgrass was more tolerant of nematode invasion, attained the greatest plant growth, and exhibited some degree of tolerance
