The reproductive potential of Meloidogyne graminicola was compared with that of M. incognita on Trifolium species in greenhouse studies. Twenty-five Trifolium plant introductions, cultivars, or populations representing 23 species were evaluated for nematode reproduction and root galling 45 days after inoculation with 3,000 eggs of M. graminicola or M. incognita. Root galling and egg production ...

In North Carolina, approximately 8% of the cucumber (Cucumis sativus) yield is lost to root-knot nematodes (Meloidogyne spp.) (Main and Gurtz, 1989). No resistance was found in cucumber after screening of 900 cultigens for resistance to Meloidogyne incognita race 3 (Walters, 1991). African horned cucumber (Cucumis metuliferus) has resistance to M. incognita (Fassuliotis, 1967; Walters, 1991), a...

The objective of this study was to evaluate sweet potato clones for resistance to root-knot nematode, Meloidogyne incognita races 1 and 3. For each nematode physiological race, a greenhouse experiment was set up in a randomized block experimental design with three replications and six plants per plot. Fifty-eight sweet potato clones from the UFVJM germplasm bank were evaluated, plus five commer...

Eight endoparasitic nematode species were recovered from 170 maize root samples in western Transvaal, Republic of South Africa. Pratylenchus zeae had the highest average population density (17,454/5 g roots), followed by P. neglectus (5,827/5 g roots), P. penetrans (5,617/5 g roots), P. brachyurus (3,060/5 g roots), Meloidogyne incognita plus M. javanica (301 juveniles/5 g roots), P. crenatus (...

In a greenhouse pot experiment on the pathogenicity and interactions of Meloidogyne incognita, M. hapla and Pratylenchus brachyurus on four cultivars o f tobacco the cultivars 'Hicks' and 'NC 2326' were susceptible to each nematode and "NC 95' and 'NC 2512' resistant only to M. incognita.Mean heights of susceptible plants were depressed but fresh weight of tops did not differ significantly. Mel...

Larvae of Meloidogyne spp. were readily infected with the endoparasite Bacillus penetrans by exposure to an aqueous suspension of spores from infected root-knot nematode females, or by passage of larvae through a shallow layer (50 cm(3)) of spore-infested soil. Infection severely reduced motility of second-stage larvae through soil. Bacillus penetrans exhibited a distinct host specificity in th...

Hyphae of Dactylella oviparasitica proliferated rapidly through MeIoidogyne egg masses, and appressoria formed when they contacted eggs. The fungus probably penetrated egg shells mechanically, although chitinase production detected in culture suggested that enzymatic penetration was also possible. In soil, D. oviparasitica invaded egg masses soon after they were deposited on the root surface an...

In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found com...

The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from a...