Host-parasite interactions between the pathogen, Sphaerulina musiva, and its host, Populus spp., were examined in a series of studies. In the first study, variation in resistance of Populus nigra from 7 locations in Europe was differentiated based on the parameters cankers per cm and disease severity score. The analysis evaluated...
Lago Rupanco is located in the central plain of Chile
(Borgel, 1964) at 40° 50' S; 72° 30' W. It lies at 117 m
above sea level, and corresponds to type 28c of Hutchinson's
(1967) classification. Lago Rupanco is a warm, monomictic
lake, with winter circulation and summer stratification.
Physical,...
The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
Winter squash (Cucurbita maxima) grown in Oregon’s Willamette Valley for edible seed, frozen foods, and fresh markets is susceptible to an undiagnosed soilborne disease. Diseased squash fields exhibit symptoms of stunting, root and crown rot, vascular discoloration, and late-season wilt, which in extreme cases can lead to total crop failure....
Modern plant pathology benefits from integrating methods and concepts from evolutionary biology. For example, evolutionary concepts are used to identify and examine species boundaries of plant pathogens, recognize processes underlying pathogen biogeography, identify traits that characterize emerging species, and discover new molecular interactions that originate under processes of selection. In...
Fungi play critical roles in ecosystem processes and interact with plant communities in mutualistic, pathogenic, and commensal ways. Fungal communities are thought to be influenced by both associated tree communities and soil properties. However, the relative importance of the biotic and abiotic drivers of soil fungal community structure and diversity...
Invasive plants have the capacity to transform landscapes and alter ecosystem function, causing significant economic and ecological damage. These effects include displacement and reduction of native flora and fauna, altered fire regimes, modification of biotic and abiotic soil properties, as well as local, regional, and global economic impacts. With such...
In the Pacific Northwest (PNW), the two most common root-knot nematodes are Meloidogyne hapla and Meloidogyne chitwoodi. These nematodes can infect a wide variety of crops and can cause significant losses. Currently, it is common for the field of nematology to use labor-intensive microscopy to identify plant-parasitic nematodes based on...
The fungus Nothophaeocryptopus gaeumannii is the causative agent of Swiss needle cast (SNC), a foliar disease of Douglas-fir. Disease is characterized by premature loss of foliage and reduced growth resulting from the inhibition of photosynthesis due to the occlusion of stomata by the ascocarps of N. gaeumannii. Although the disease...
Anthropogenic induced climate change is predicted to alter distribution of existing plant populations. As plants migrate over space and time, populations often fragment and contract, affecting basic elements of population dynamics (e.g., population size, gene flow, genetic diversity, etc.). Little is known, however, how these impacts on plant species will...