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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Natural control of soil inhabiting nematodes.

Khan, Shakil Ahmad. January 1973 (has links)
No description available.

Effect of antibiotics on a free-living soil nematode, Rhabditis briggsae

Briggs, Margaret Poole, January 1950 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1950. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 62-[64]).

A study of a species of the nematode genus Macrophosthonia.

Faghihi, S. Jamaleddin. January 1978 (has links)
No description available.

Ecology of the mycophagous nematode, Aphelenchus avenae /

Walker, Gregory Ernest. January 1984 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept of Plant Pathology, 1985. / Includes bibliographical references (leaves 214-221).

Soil nematode communities in grasslands : effects of plant species identity and diversity /

Viketoft, Maria, January 2007 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2007. / Thesis documentation sheet inserted. Includes appendix of five papers and manuscripts, three co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

Ecology of the mycophagous nematode, Aphelenchus avenae / by Gregory Ernest Walker

Walker, Gregory Ernest January 1984 (has links)
Bibliography: leaves 214-221 / viii, 221 leaves, [19] plates : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Pathology, 1985

Recolonization of arthropod and nematode assemblages in reclaimed mineland soils of Wyoming

Regula, Victoria A. January 2007 (has links)
Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Nov. 7, 2008). Includes bibliographical references.

Verticillium wilt, nematodes, and soil fertility interactions in hop yards

Barth, Alexander W. 25 July 1990 (has links)
Verticillium wilt of 'Willamette' hops (Humulus lupulus) was investigated to identifY the causal organism, to determine the incidence of the disease, and to explore the possibility of interactions with soil fertility and/or nematodes. In the first year of a three year study, sampling of yards followed a "searching for extremes approach". Selection of yards was based on a preliminary survey of all (35) hop growers in the Willamette Valley. Participating growers (10) were asked to identify one "good" and one "not-so-good" yard. Each of the 20 specified yards was subdivided into 4 plots; two representing a "good" and two representing a "not-so-good" area. In all 80 plots, data were collected to determine incidence of vascular colonization by Verticillium and stem necrosis in vines; soil and root parasitic nematode populations; concentrations of nitrate-N, ammonium-N, P, K, Ca, Mg, and pH in the soil surface, and nitrate-N, ammonium- N , and K in the subsoil; concentrations of total-P, K, and Zn in the leaves; and concentrations of nitrate-N, phosphate-P, and K in the petioles. The causal agents of the wilt were Verticillium dahliae in 13 yards and V. albo-atrum in one yard. Recovery of the pathogen within a yard ranged from 0 to 50% of sampled vines, while stem necrosis ranged from 0 to 68%. The frequency of infection was not significantly different among plots or yards, which suggests that the disease is present in all hop growing districts in Oregon. Soil nematode populations ranged from 0 to 3000 juveniles/100 g of dry soil. Heterodera humili (hop-cyst nematode) was the predominant parasitic nematode, while Pratylenchus (root-lesion nematode) and Paratylenchus (pin nematode) were recovered only occasionally. Densities of nematodes extracted from roots ranged from 0 to 2000 juveniles/g of moist root material and were primarily H. humili. A significant association between nematode populations and Verticillium incidence was not detected. Soil nutrient concentrations exhibited a high degree of variability among yards. The nitrate-N content, measured to a depth of 36" (90 cm) for individual hop yards, ranged between 65 (73) and 417 lb/A (468 kg/ha) with a mean value of 270 lb/A (302 kg/ha). Concentrations of ammonium-N were determined to be approximately one-fourth of the nitrate concentrations. Phosphorus and potassium concentrations ranged from 55 to 155 ppm and 118 to 799 ppm, respectively, in the surface soil. For the same depth, soil pH ranged from 5.15 to 6.78. Petiole concentrations of nitrate-N and potassium ranged from 0.16 to 1.3% and from 1.26 to 6.84%, respectively. While it is believed that the duration of the sampling period may have been responsible for the wide range in nitrate-N values, petiole potassium concentrations are thought to reflect the potassium content in the soil. The concentrations of K in petioles increased steadily with increasing soil test values up to 350 ppm K. Soil and tissue nutrient concentrations found within and among hop yards did not correlate significantly with the incidence of Verticillium wilt. However, petiole nitrate-N concentrations were significantly higher (p < 0.05) in plots infected with Verticillium (0.73%) as compared to noninfected plots (0.56%). / Graduation date: 1991

The distribution and abundance of nematodes (especially the plant parasites) in the arid region of South Australia /

Nobbs, J. M. January 1987 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Plant Pathology, 1987. / Includes bibliographical references.

Spatial distribution of soil nematodes in the sub-arctic environment of Churchill, Manitoba

Lumactud, Rhea Amor 07 April 2010 (has links)
The tundra ecosystem, with its frost-molded landscape and large peat reserves, is vulnerable to climate change. Thus, any increase in temperature due to global warming will cause changes in above-and belowground biota. Understanding the linkage between these biotas will help make prediction of the biodiversity and ecosystem functioning when global change phenomena occur, and consequently aid in making management strategies. The role of nematodes in nutrient cycling and decomposition, among many other attributes, make them useful organisms to study soil processes. Associations between plant and nematode communities, from six sites (Berm Face, Berm Crest, Tundra Heath, Polygon, Hummock and Forest) and from within a young, visually homogeneous tundra heath field site, were examined in the subarctic environment of Churchill, Manitoba. The study also provided nematofaunal information, which is very limited in this region. Multivariate analyses of nematode taxa abundance revealed four distinct groupings: Berm Face, Berm Crest, heaths (Tundra Heath, Polygon and Hummock) and Forest. The result showed a parallel relationship between nematode and vegetation assemblages, and thus, a seeming interdependency between above-ground and below-ground biota. Conversely, association between nematode and plant assemblages within a visually homogeneous tundra site was not as obvious. At this fine scale, the heterogeneous nature of edaphic factors and not plant assemblages is hypothesized to influence within-site nematode communities. The thesis also provided results to improve nematofaunal analysis to enhance their utility as bioindicators of soil food webs.

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