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...
The certified organic blueberry (Vaccinium sp.) market has continued to expand in the last two decades, including in Oregon. The development of an industry-public research coalition has fostered expansion. In 2015, a survey consisting of on-site, in-person interviews with certified and transitional organic growers in Oregon found the majority of...
A rapid and sensitive HPLC method for quantifying both the
reduced and oxidized forms of glutathione simultaneously in woody
plant tissues was developed. This method was applicable to a variety
of woody plant species and different tissues. Total glutathione
content in the bark tissue of seven of the woody plant...
In the Northwest, two tree fruit production problems may be
related to the role of ethylene on plant growth and development:
flowers and developing fruits are subject to low temperature injury
during early spring, and to the low fruit set of 'Comice'. Ethylene
may be involved in influencing dormancy and...
Dormancy of 'Pinot Noir' grapevines was characterized. Primary buds
required ca 300 cumulative chilling hours (CCH) to initiate the transition from
endodormancy to ecodormancy, which occurred in mid November. Additional
chilling, up to 1000 CCH, improved budbreak. Changes in bud water content
were estimated by gravimetric and spectroscopic methods. Total,...
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...
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,...
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...
Inheritance of eight enzyme systems, alanine aminopeptidase (AAP), aspartate
aminotransferase (AAT), aconitase (ACON), glucose phosphate isomerase (GPI),
malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6-PGD),
phosphoglucomutase (PGM), and shikimate dehydrogenase (SDH) was studied in
hazelnut (Corylus avellana L.) by either polyacrylamide gel electrophoresis
(PAGE) or starch gel electrophoresis. Three isozymes were detected...
Pollen development is an important process in male flower development, the timing of which may be correlated with time of pollen shed in hazelnut (Corylus avellana L.). Early to very late blooming cultivars were identified and the relationship of microsporogenesis and microgametogenesis, and time of pollen shed were studied in...