Variability of morphological characters used to separate Pratylenchus penetrans from other species of the genus was studied in a population originating from a single gravid female. Pronounced heteromorphism was observed and characterized. About 30% of females had a crenate-tail terminus. Several shapes of stylet knobs were characterized; 50% of them were anteriorly flattened to indented. The ou...

Plants need to defend themselves against their natural enemies without compromising their interactions with beneficial organisms. Chemical mechanisms underpin many of these interactions and changes in plant metabolism are critical to both robust defences against antagonists and effective signals to mutualists. Further, such plant responses can be systemic, so mediating interactions between spat...

The effects of Pratylenchus penetrans upon yields of 'Veebrite' tomato were studied at initial soil population densities (P(i)) of 360, 2,010, 4,580, and 14,360 nematodes/kg of soil in 20-cm (i.d.) clay-tile microplots. The lowest P(i) appeared to stimulate fruit production. Higher P(i)'s suppressed fruit production (total weight of marketable tomatoes and numbers of intermediate- and large-siz...

The pathogenicity and interactions of Meloidogyne naasi, Pratylenchus penetrans, and Tylenchorhynchus agri on 'Toronto C-15' creeping bentgrass, Agrostis palustris, was studied in a long-term greenhouse experiment. Based on dry weights of roots and clippings, M. naasi alone and in all combinations with P. penetrans and T. agri was highly pathogenic to creeping bentgrass. P. penetrans and T. agr...

Rotylenchulus reniformis is one of 10 described species of reniform nematodes and is considered the most economically significant pest within the genus, parasitizing a variety of important agricultural crops. Rotylenchulus reniformis collected from cotton fields in the Southeastern US were observed to have the nematode parasitic bacterium Pasteuria attached to their cuticles. Challenge with a P...