Assessing the risk from exposure to a chemical mixture in the environment can seem prohibitively challenging. Most components of the mixture are not readily identifiable, chemicals may interact to cause other-than-additive toxicity, and the number of potential combinations of environmental contaminants is enormous. These challenges can make it seem impossible...
Human exposure to the carcinogenic polycyclic aromatic hydrocarbons (PAHs) benzo[a]pyrene (B[a]P) and dibenzo[a,l]pyrene (DB[a,l]P) is through environmental complex mixtures, such as urban dust particulate matter (UDPM) and diesel exhaust (DE), however the potency of these PAH within a mixture is not established. To determine the effect of these mixtures on...
The level of polymorphisms of many biochemical and DNA markers are low in
cultivated sunflower (Helianthus annuus L.). The number of mapped public DNA
markers is limited. Molecular markers have not been developed for the most
important diseases of sunflower, such as downy mildew. The objectives of this
study were...
Elite inbred sunflower (Helianthus annuus L.) lines were found to have short-lived embryo and seed covering dormancies. Seed dormancy of wild sunflowers (H. annuus, H. argophyllus and H. exilis) was found to be controlled primarily by the seed covering (seed coat and pericarp) and embryo dormancy was short-lived (four to...
During the last century, fire suppression, grazing, and climate change have caused sagebrush grasslands to be altered in both function and form; juniper and sagebrush dominate the landscape at the expense of herbaceous plants. Management efforts to reduce juniper and sagebrush overstory in order to enhance herbaceous components of the...
Time-course growth chamber studies were conducted on little mallow
(Malva parviflora L.) to determine whether sublethal doses of lactofen
(1'-(carboethoxy)ethyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-
nitrobenzoate) would enhance uptake of glyphosate (N'-(phosphonomethyl)
glycine) by altering membrane permeability. Lactofen-induced membrane
peroxidation was determined by harvesting leaf discs, measuring stress
ethylene evolution, and recording increases in...
Two field corn experiments were conducted on a Woodburn silt loam soil near Corvallis, Oregon, in 1972-1973 to investigate the effects of certain soil management practices on the yield and performance of corn (Zea mays L.). Experiment I involved variables that included three corn row spacings (76, 114, and 152...
Highbush blueberry (Vaccinium corymbosum L.) is adapted to soils with high organic matter and acidic pH. Composts provide organic matter and nutrients for growing blueberry in mineral soils, but many composts are high in pH and soluble salts. Acidification with elemental sulfur (S°) can remedy high pH, but the process...
The cultivated sunflower (Helianthus annuus L., x=17) is one of the most important annual oilseed crops in the world. There are very few publicly shared sequence-based DNA markers and genetic maps in sunflower, even though molecular DNA markers and genetic maps have become widely used in all areas of genetic...
Field experiments were established in 1982 and 1983 on a Woodburn silt loam soil (Aquultic Argixeroll) to examine the effect of S fertilizer on dinitrogen fixation and dry matter yield of 10 week-old seedling alfalfa (Medicago sativa L. cv. 'Apollo'). Six levels of S fertilizer (0 to 67.2 kg S/ha)...