Polycyclic aromatic hydrocarbons (PAHs) are a class of usually planar
compounds consisting of fused aromatic rings that are formed by the incomplete
combustion of organic materials. PAHs are ubiquitous in the environment, coming from
a number of sources, such as cigarette smoke, the burning of wood for residential heating,
and...
Biological control is the action of predators, parasitoids, or pathogens to maintain
a pest organism's population at lower numbers than would occur in the absence of the
agent. Entomopathogenic nematodes can be used as biological control agents for insect
pests. These nematodes infect insects and release a toxic bacterium that...
This study examined the management situation for the Columbiaroot-knot nematode (Meloidogyne chitwoodi) in potato, using an approach with systems thinking and interactive meetings. The focus of current research for control of this nematode was evaluated. Control practices include crop rotation, and this study also evaluated popcorn cultivars for their potential...
Surfactants, or surface active agents, are the active ingredients in detergents used for
domestic cleaning applications, such as dish washing and laundering. They are effective cleaning
agents by concentrating at interfacial regions, lowering the surface tension of water, and forming
micelles that solubilize oils (West, 1992). Surfactants are amphiphilic, because...
Evaporative loss rates of pesticides, following application to turfgrass, were measured using the Backward-Time Lagrangian stochastic Dispersion model (Flesch, Wilson, Journal of Applied Meteorology, 34, pp. 1320-1332. All pesticides were applied to a 22.8 m x 22.8 m orchard ryegrass turf plot near Corvallis, Oregon. Solar radiation, ambient temperature, surface...
Leaves of healthy strawberry plants were inoculated with either vinclozolin-sensitive or vinclozolin-resistant isolates of Botrytis cinerea at one of three concentrations: 5x104, 1x105, and 5x105 conidia/ml. One week following inoculation, representative leaves were harvested and cut into 9mm2 leaf pieces. Some pieces were immediately plated onto selective Botrytis medium while...
Separation and isolation of organic analytes from environmental matrices such as soils,
water, plant, or animal tissue has traditionally involved the use of liquid solvent extractions.
Solvent-based extraction methods are often time-consuming, difficult to automate, and use
expensive solvents that generate hazardous waste and working conditions. The need for a...
Nitrosomonas europaea is an autotrophic ammonia-oxidizer that has been found to cometabolize various halogenated hydrocarbons. This ability to cometabolize various compounds (many of which are considered contaminants) has caused N. europaea to be considered a potential bioremediational organism. However, ifN. europaea is to be used for bioremediation purposes, it will...
As in other species, it is possible that a homozygous red leafed (= redleaf) hazelnut (Corylus avellana L.) tree would have brighter red coloration than a heterozygote and thus be more desirable as an ornamental. However, 'Fusco Rubra' and `Rode Zeller' both carry incompatibility allele S6 (thus cross-incompatible) and are...
Saturated soils undergo reduced conditions as microorganisms consume oxygen and require other terminal electron accepting processes for the mineralization of soil organic carbon. Currently, the soil redox potential has not been considered as important when sampling these soils for Fe, Mn, and P04. Since Fe- and Mn-oxides are electron sinks...
This report examines the feasibility of using the bivalve Corbicula flumina as a biomarker for environmental contaminants in the Willamette River. Compounds such as DDT, dioxins, furans, and PCBs persist in the environment, pose health related concerns, and due to their lipophilic nature accumulate in biological organisms. The success of...
Pole-sized, live western larch Larix occidentalis Nutt.) were inoculated with Ophiostoma pseudotsugae(Rumb.) von Arx or Leptographium abietinum (Peck) Wingf., two blue stain fungi associated with the Douglas-fir beetle (Dendroctonous pseudotsugae Hopkins), to assess their pathogenicity. Inoculation with O. pseudotsugae resulted in a significantly greater percentage of necrotic phloem compared to...
Rapid and accurate analytical methods are needed to assess the impacts of agricultural chemicals on soil and water resources. Solid-phase extraction (SPE) was evaluated as an alternative method to conventional liquid-liquid extraction for the quantitative analysis of the herbicide DCPA and its metabolites in ground waters. Strong anion exchange (SAX)...
Ontogenetic niche shifts are critical times in a fish's life that need to be passed for
survival, growth and recruitment (Gerking 1994, Osenberg et al. 1994). These niche
shifts are identified by a change in feeding from one prey type to another. These shifts in
feeding occur throughout growth and...
Much interest has recently been shown in using fecal samples to monitor
hormone concentrations in free-roaming animal populations. This process is noninvasive
and, therefore, provides easy sample collection and assures no stress-related,
physiological responses that might alter the hormonal data. Concerns have been
expressed, however, that the hormone concentrations detected...
Contamination of water sources due to the use of agricultural chemicals can be minimized through understanding the transport relationships for organic chemicals in soil environments. In this study we evaluated seven non-hazardous dyes that have properties which were consistent with application as surrogates to organic agro-chemicals to assess mobility through...
Squash varieties of Golden Delicious and Squash Hybrid NK 530 were grown in disk-till, strip-till, and no-till conservation tillage systems following a cover crop of'Monida' oats (Avena sativa L.) and common vetch (Vicia sativa L.). Tillage systems were evaluated for effects on squash emergence and yield, weed density and biomass,...
Seasonal reducing conditions play an important role in the cycling of nutrients and soil pore water chemical constituents in the Willamette Valley. Long periods of soil saturation lead microorganisms utilizing organic matter as their carbon source to find alternative electron acceptors other than oxygen. Once oxygen has been depleted microorganisms...
A broad range of factors influence wine grape quality and manipulation of these factors has stimulated interest among grape growers, wine makers, and research scientists alike. One such factor affecting wine grape quality is crop level, particularly for Pinot noir. Since the capacity of a vine to ripen fruit depends...
South American waterweed, Elodea densa (Planch.) Casp., and Coontail Ceratophyllum demersum L., were studied for their potential to take up chromium and zinc and as a possible indicator of arsenic, cadmium, copper, and lead pollution. Plants were collected from the Willamette River in Oregon and exposed for 48 hours to...
