Soils and roots of field crops in low-rainfall regions of the Pacific Northwest were surveyed for populations of plantparasitic and non-plant-parasitic nematodes. Lesion nematodes (Pratylenchus species) were recovered from 123 of 130 non-irrigated and 18 of 18 irrigated fields. Pratylenchus neglectus was more prevalent than P. thornei, but mixed populations were common. Population densities in ...

Growth and yield of cotton were best with combinations of fumigants and organophosphate and carbamate nematicides. Organophosphates or carbamates used alone did not give season-long control of root-knot nematodes. Long-term control was poor because the temporary sublethal effects of these materials diminished soon enough lhat the nematodes could reproduce. The nematodes survived the treatments ...

Recent advances in molecular biology have enabled the genotyping of individual nematodes, facilitating the analysis of genetic variability within and among plant-pathogenic nematode isolates. This review first describes representative examples of how RFLP, RAPD, AFLP, and DNA sequence analysis have been employed to describe populations of several phytonematodes, including the pinewood, burrowin...

Selection of detectable numbers of Mi-virulent root-knot nematodes has necessitated a greater understanding of nematode responses to new sources of resistance. During the course of this research, we compared the reproduction of four geographically distinct Mi-virulent root-knot nematode isolates on three resistant accessions of Lycopersicon peruvianum. Each accession carried a different resista...

Nematode occurrence at specific locations throughout a water catchment-irrigation system was determined. Soil samples were collected from five water source locations on the slopes of Olomana Mountain and Maunawili Valley and from about 40 plant species on 18 farms (56 ha of 480 ha irrigated by the reservoir). Water was sampled from the catchment reservoir at 0.3 m, 9 m, and 18 m (bottom). A far...

Interactions between root-knot nematodes and viruses were recently reviewed by Taylor (4). Compared to virus-free cowpea (vigna sinensis Endl.), cowpea mosaic virus-infected plants formed fewer galls on roots in response to infection by Meloidogyne incognita (Kofoid and White) Chitwood (2). On the other hand, tobacco plants (Nicotiana tabacum L.) infected with tobacco ringspot virus (TRSV) and ...

This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric ...