The pathogenic effects of Pratylenchus coffeae on growth and yield of tangelo (Citrus paradisi x C. reticulata) scions grafted on rough lemon (C jambhiri), sour orange (C. aurantium) and 'Cleopatra' mandarin (C. reticulata) rootstocks were evaluated under field conditions for 4 years. Pratylenchus coffeae on inoculated trees increased to significantly damaging population densities on rough lemo...

Corn yields were measured after application of nematicides in 16 experiments, mostly in medium-to-heavily textured soil, at 12 locations in Iowa during 1973-1976. The average maximum yield increase in plots treated with nematicides was 21% over yields in untreated plots. Yields were correlated negatively with nematode numbers or nematode biomass in nearly all comparisons. Correlations of nemato...

Faces of lesion nematodes Pratylenchus teres (populations RTB and JK) and P. zeae or the bacterivore Distolabrellus veechi were observed on frozen specimens with low-temperature scanning electron microscopy and as chemically fixed, critical-point dried specimens with conventional scanning electron microscopy. Amphidial secretions were preserved in chemically fixed but not cryofixed lesion nemat...

Daily irrigated, 80% pan replacement, and nonirrigated field plots of Kentucky bluegrass (Poa pratensis L.) were inoculated with a mixture of Steinernema carpocapsae (All strain) and Heterorhabditis bacteriophora (HP-88 strain) in 1988. In 1989, daily irrigated and nonirrigated plots were inoculated with HP-88 alone. The turf and associated soil contained populations of Tylenchorhynchus dubius,...

Yams (Dioscorea spp.) are food crops of growing significance in sub Saharan Africa. Unfortunately, nematodes are major pests to their production. A study was undertaken in major yam growing areas of Uganda to investigate the association of plant parasitic nematodes with damage symptoms. Nematodes were assessed from tubers, roots and surrounding soil for seven cultivars belonging to Dioscorea al...

Host suitability of commercial sunflower hybrids to Pratylenchus zeae was studied in the field and greenhouse. For comparison, one maize and one grain sorghum inbred line, both susceptible to P. zeae, were included in the greenhouse experiments. Pratylenchus zeae densities extracted from the roots of sunflower hybrids grown in naturally infested soil were low. In the first greenhouse experiment...

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...

The esophageal glands in the genus Pratylenchus occur in a large, single ventral lobe except for four populations in which a few specimens had the glands located dorsally. Apratylenchoides belli n. gen. n. sp. in the subfamily Radopholinae is proposed for a species having two esophageal glands in a large dorsal lobe and one gland in a smaller, shorter ventral lobe.