Previous studies indicated that fertigating with nitrogen (N) was more effective than using granular N fertilizers in production of northern highbush blueberry (Vaccinium corymbosum L.). To build on these findings, four studies were conducted in western Oregon to determine whether fertigation was also an effective method for applying other nutrients,...
Five boron rates and seven water levels were applied
to bush green beans (Phaseolus vulqaris cv Oregon 91G) and
to cauliflower (Brassica olereacea var. botrytis, cultivar
"Snowball Y") in 1989 and 1990 to evaluate their effects on
total yield of both crops and on outer quality, head
hollowness and internal...
The goal of the work in this dissertation was to identify alternative soil amendments to improve plant growth and yield during establishment of highbush blueberry (Vaccinium hybrid). Woody materials, such as sawdust and wood chips, have a high carbon to nitrogen (C:N) ratio and low water holding capacity, which can...
The impact of fertilizer source and cultivar on growth, fruit quality, and yield was evaluated in organic blackberry (Rubus L. subgenus Rubus Watson) from 2011-2013 in three studies. In all studies, plants were drip irrigated, and weeds were managed using a woven polypropylene, permeable landscape fabric (weed mat). At a...
Escalating demand for organic blueberries has driven a significant expansion of northern highbush blueberry (NHB; Vaccinium corymbosum L.) production area. This expansion is particularly pronounced in regions of the Pacific Northwest where native soil conditions are sub-optimal for NHB, notably east of the Cascade Mountain Range of Oregon and Washington,...
As blueberry (Vaccinium sp.) production has increased in recent decades, a new interest has developed in the cultivation of blueberry in soilless substrate containers. Historically, blueberry has been propagated and grown in soilless substrate at nurseries, but nursery production is short in duration and plants are small relative to a...
Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for...
Biochar is a highly porous, carbon-rich residue produced by thermochemical conversion (pyrolysis) of plant biomass and carbonaceous organic materials under oxygen-controlled conditions. Chars produced by this process tend to have high ion-exchange capacities and, when added to soil, increase retention of water and nutrients and improve soil aggregation, porosity, and...
Northern highbush blueberry is a long-lived perennial crop that is well adapted to low soil pH conditions. The plants are often shallow rooted and absorb primarily the ammonium (NH₄) form of nitrogen (N) rather than nitrate-N (NO₃-N). Traditionally, commercial blueberry fields have been irrigated with overhead sprinklers and fertilized using...
The Pacific Northwest region of the United States is known for quality production of blueberries, blackberries, and red raspberries. However, as the climate shifts to warmer, drier, and more extreme summers, growing these water intensive berry crops is becoming increasingly difficult. Furthermore, water regulations within agriculture are becoming more prevalent...