Specialty organic fertilizers used in organic vegetable production are expensive. So, from environmental and economic perspectives, growers want to maximize nitrogen (N) fertilizer use efficiency by the crop. This research was conducted to (1) determine sufficient N fertilizer rates for organic broccoli, (2) evaluate the efficacy of a specialty organic...
Specialty organic fertilizers used in organic vegetable production are expensive. So, from environmental and economic perspectives, growers want to maximize nitrogen (N) fertilizer use efficiency by the crop. This research was conducted to (1) determine sufficient N fertilizer rates for organic broccoli, (2) evaluate the efficacy of a specialty organic...
Despite increasing consumer demand for organic food and farm products and double-digit annual sales growth, U.S. organic production is currently flat and unable to meet demand. This report presents findings from a national survey of farmers about their experiences with organic transition, exploring motivations, obstacles, and desired resources and support...
In the midst of double-digit growth in market demand for organic products, there is a lag in the growth of certified organic production in the United States. This thesis investigated the motivations and barriers farmers face when making the transition to organic agriculture. Three distinct organic farmer typologies were identified:...
This study investigates the relationship between total and ionic copper in samples taken from the Tualatin River and wastewater treatment facilities (WWTFs) that discharge into the Tualatin River. Copper speciation was analyzed by determining conditional stability constants and densities of copper binding ligands on the dissolved organic matter (DOM) in...
Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less...
There is limited information available on production of trailing blackberry, particularly certified organic plantings, which are of interest to growers as there is increased consumer demand and a price premium over conventionally-produced fruit. Various production strategies were evaluated for their effect on yield, biomass production, carbon (C), and nutrient concentrations...
Phytophthora cinnamomi is a soilborne pathogen that causes root rot disease of highbush blueberry (Vaccinium corymbosum L.). When new installations of susceptible blueberry cultivars are infected with P. cinnamomi, plants often fail to grow significant new tissue, greatly reducing yields over the life of the planting. Chemical fungicides are available...
Blackberry (Rubus sp.) fruit are a good source of phenolic compounds and anthocyanins, and are consumed in fresh and processed forms. Though organic products become more popular, limited information is available about how different organic production methods affect the post-harvest quality of blackberry fruit. The objective of this project was...