OSU BLUEBERRY SCHOOL
March 16-17, 2015
held at
Oregon State University, Corvallis, Oregon
This two-day blueberry “school” was organized for new and experienced blueberry growers,
farm managers, crew leaders, advisors, packers/shippers, and consultants. Experts from Oregon
State University, USDA Agricultural Research Service, Washington State University, and the
blueberry industry were asked to address key issues of where the blueberry market is going; how
you might be more successful in tight labor or volume markets; which cultivars are easiest to
grow and are in most demand; how to establish new acreage using cutting-edge methods;
projected costs and the resources available to growers for selecting new planting sites; how to
best manage existing acreage to maximize returns of high-quality fruit; provide basic information
on blueberry plant physiology to help growers minimize environmental stresses and improve
yield potential; nutrient management programs for optimal growth and quality; irrigation and
fertigation practices for higher quality and better efficiency; use of organic amendments and
mulches; planning for and improving machine harvest efficiency; pruning for hand or machine
harvest (where can you cut corners….or not), maximizing pollination for good fruit and seed set;
overviews of the most important blueberry viruses, diseases, insects, weeds, and vertebrate pests;
and tools for good pest management. Information throughout the program addresses the needs of
conventional, transitional, and organic growers. Simultaneous interpretation to Spanish has been
provided. This proceedings book contains information provided on these topics by each speaker
and co-authors. The thumb drive provided in the registration packet for each attendee includes a
copy of each presentation. Thank you for attending. It is our sincere wish that this will be a very
useful meeting and that you find the accompanying materials a valuable reference! –
Bernadine Strik, Professor and Extension Berry Crops Specialist, OSU and the members of the
organizing committee
Organizing Committee
Bernadine Strik, Chair, Oregon State University (OSU)
Wei Yang, OSU. Co-chair (sponsorship coordinator), OSU
Donna Williams, Rachel Williams & team at OSU Conference Services
Dave Bryla, USDA-ARS HCRU
Chad Finn, USDA-ARS HCRU
Vaughn Walton - OSU
Steve Castagnoli - OSU
Steve Renquist - OSU
Bryan Ostlund – Oregon Blueberry Commission
Eric Pond - industry
Jon Umble – industry
Derek Peacock - industry
Steve Erickson - industry
Nancy Jensen - industry
i
Table of Contents
OSU Blueberry School
Title
Authors
Characteristics of production regions in the Pacific
Northwest
Lisa DeVetter, Pat Jones, Bernadine
Strik, Kathie Dello
1
Markets - what's the future for fresh, processed, and
organic markets? Things you MUST think about before
starting or expanding production
Rod Cook, Derek Peacock, Jeff
Malensky, David Granatstein
9
Cultivar choices- Tried and true to brand new
Chad Finn and Bernadine Strik
15
Economics of production – resources
Bernadine Strik and David Granatstein
29
Resources available for selecting a good blueberry site
Wei Q. Yang
37
Site selection and establishment of a blueberry field
Wei Q. Yang and Bernadine Strik
41
Organic soil amendments and mulches for blueberry:
the good, the bad and the ugly
Dan Sullivan (OSU)
47
On-farm irrigation system design and operation
David Bryla
53
Blueberry plant physiology - why it's important to
understand the plant to manage it well
Bernadine Strik
57
Irrigation scheduling: when, where, and how much?
David Bryla
63
Pruning - impact of plant age, cultivar, and harvest
method
Bernadine Strik
69
Harvesting - hand vs. machine
Bernadine Strik (moderator); Paul
Norris (Norris Farms); Frank Brown
(Littau Harvesters (Inc.); Doug
Krahmer (Berries Northwest)
75
Nutrient management of blueberry -- assessing plant
nutrient needs and designing good fertilizer programs
Bernadine Strik and David Bryla
79
Maximizing pollination in blueberry
Ramesh Sagili, Carolyn Breece, John
Borden
95
Blueberry viruses present in the Pacific Northwest and
suggestions for their management
Robert Martin
99
Blueberry bacterial and fungal diseases
Jay Pscheidt and Jerry Weiland
107
ii
Page
Title
Authors
Page
Weed management for blueberry fields in the Pacific
Northwest
Tim Miller
115
Getting hit high and low: Options for managing bird
and vole damage
Dana Sanchez (OSU
125
Management of arthropods, insect, and plant-parasitic
nematodes in blueberries
Vaughn Walton,Nik Wiman, Inga
Zasada, Joe DeFrancesco, Daniel
Dalton, Amy Dreves, Jana Lee, Lynell
Tanigoshi, Wei Yang
129
iii
Characteristics of Production Regions in the Pacific Northwest
Lisa DeVetter2, Pat Jones1, Bernadine Strik1, and Kathie Dello3
Department of Horticulture, Oregon State University; 2Washington State University, Mt.
Vernon, NWREC; 3Associate Director of OCCRI; Deputy Director, Oregon Climate Service,
Oregon State University
1
PACIFIC NORTHWEST BLUEBERRY PRODUCTION
Blueberry has risen to be the second most important commercial berry crop in the United States
and had an estimated crop value of $851 million dollars in 2012 (Geisler, 2013). Demand is also
increasing in international markets, including Asia and Europe (ISE, 2014). Fueling this
increased demand for fruit is the successful marketing campaigns that advertise the multiple
health benefits from blueberry consumption. The United States and Canada lead global blueberry
production in terms of total area in production (ISE, 2014). Much of this production is
concentrated in the Pacific Northwest (PNW), specifically Oregon, Washington, and British
Columbia. Highbush blueberry (Vaccinium corymbosum) has shown to be well adapted and
productive under the climactic conditions of the region. Approximately 90 and 82 million pounds
of fruit were harvested in Oregon and Washington, respectively, in 2013 (NASS, 2014).
Combined, this amounts to 32% of the total crop produced in the United States from 18,600
acres (9,600 acres in Oregon and 9,000 acres in Washington). In British Columbia, blueberries
are cultivated on 28,000 acres of land located in the western coastal regions of the province (B.C.
Blueberry Council, 2014). Production in this region of the PNW is significant, with annual
production estimated at 152 million pounds of fruit. Average reported yields per acre for the
region are comparatively low due to the large number of immature fields. The PNW blueberry
industry is expected to continue increasing within the next 5 to 10 years as these new and
immature fields come into full production
Also expanding is acreage of organic blueberry production, particularly east of the Cascade
Mountains in Washington and in the Willamette Valley and southern regions of Oregon. Organic
blueberry acreage in the United States is estimated to have increased nine fold from 2003 to
2011, with over 60% of this acreage in the west coast. Oregon and Washington are leaders in this
increase in organic acreage (Strik, 2014). Over 20% of the total blueberry acreage in Oregon and
Washington was certified organic in 2011, which has increased from less than 5% seven years
prior.
The climate, availability of suitable land for production, infrastructure, and previous
knowledge/experiences of horticultural crop production among growers are strong advantages
for the Washington, Oregon, and B.C. blueberry industries. The B.C. Blueberry Council,
Washington Blueberry Commission and Oregon Blueberry Commission also support the industry
through promotion and funding of needed research. Collaborative relationships among
researchers, extension faculty, consultants, and growers within the Pacific Northwest also
strengthen the industry. Access and availability of labor is a challenge, particularly for fresh
market growers that handpick fruit. Management of Spotted Wing Drosophila (SWD) in
conventional and organic systems is another industry challenge. A related challenge for growers
exporting fruit is the production of berries that adhere to maximum residue level standards
1
established by importing countries. Here we report on the characteristics of the Washington and
Oregon blueberry industries.
WASHINGTON
Production. Washington’s blueberry industry began over fifty years ago as small farming
operations that primarily retailed fruit directly from farms. The blueberry industry has since
expanded, with statewide production increasing from 28 million pounds in 2008 to 82 million
pounds in 2013 (NASS, 2014). As of 2013, 9,000 acres of land were dedicated to blueberry
production, making Washington the fourth largest national producer in acres harvested after
Michigan, Georgia, and Oregon. Production has continued to increase and was expected to
exceed 90 million pounds in 2014 (Schreiber, 2014). Commercial production was initially
limited to western Washington, particularly Whatcom and Skagit Counties. Increased demand
for fruit has supported the expansion of the industry east of the Cascade Mountains, with Benton
and Franklin Counties experiencing significant increases in blueberry acreage. Additional growth
has, and is continuing to, occur in Snohomish, Walla Walla, and Grant Counties. Washington
also leads in organic blueberry production, with the majority of production occurring east of the
Cascade Mountains (NASS, 2012).
Climate. The climate of Washington is shaped and divided by the Cascade and Olympic
Mountain ranges. Western Washington’s maritime climate is mild and humid due to prevailing
westerly winds moving moist air from the Pacific Ocean across the region. As this air moves
inland and encounters the Cascade Mountains, it condenses and produces the precipitation that
characterizes western Washington. A rain shadow is subsequently created on the leeward side of
the mountain range, leading to the semi-arid climate experienced in eastern Washington. Moist
oceanic air also interacts with the Olympic Mountains, causing variation in precipitation within
western Washington. Seasonal high and low pressure systems further influence the seasonality of
western Washington’s climate. High pressure systems in spring and summer result in prevailing
northwesterly winds that create relatively cool and dry springs and summers. In autumn and
winter, prevailing winds become southwesterly and move warm, moist air across the region.
These air masses bring the predicable wet seasons during fall and winter months.
Depending on location, western Washington may experience 25 to 180 inches of annual
precipitation, with areas of greatest precipitation at higher elevations (e.g., Olympic Peninsula
and Mount Baker). Blueberry-growing regions in western Washington can receive 30 to 60
inches of precipitation per year, again depending on location and year (Table 1). Average high
and low temperatures for these regions are approximately 60 °F and 40 °F, respectively, with an
average temperature of approximately 50 °F. In contrast, some of the major blueberry-growing
regions in eastern Washington may receive 30 inches of annual precipitation or less.
Precipitation may sometimes be as little as 6 inches per year, making irrigation critical to
agricultural production in the region. Average high and low temperatures for this region are 64
°F and 38 °F, respectively. However, the region experiences more temperature extremes relative
to western Washington. For example, the extreme high and minimum temperatures for Prosser
within the past five years were 103.9 °F and 0.6 °F, respectively. Summer temperatures in
eastern Washington are generally 15 to 25 °F warmer than coastal regions of Washington. The
range for number of frost free days according to the Natural Resources Conservation Service for
2
Whatcom, Skagit, Benton, and Franklin counties are 150-190, 160-210, 165-210, 180-200 days,
respectively. Table 1 provides more specific climatological data for four blueberry-producing
counties in western and eastern Washington. Additional climatological data can be found at
WSU AgWeather Net, or: http://weather.wsu.edu/awn.php.
Table 1. Climatological data from western and eastern Washington. Data represent the
five-year averages of four western and eastern counties that cultivate blueberries.*
Western Washington
Skagit
Whatcom County
County
Eastern Washington
Benton
Franklin
County
County
Air Temperature
Average (°F)
50.1
50.8
52.1
54.5
Extreme min. (°F)
5.3
7.8
0.6
-4.8
Extreme max. (°F)
96.6
87.4
103.9
107.8
Precipitation (inches)
36 (± 4.2)
32.5 (± 4.5)
7.2 (± 2.5)
4.6 (± 1.2)
*Temperature data averaged from 2010 to 2014. Weather data provided courtesy of WSU AgWeatherNet. Data are
copyright of WSU.
Western Washington growers report reductions in fruit set and yield due to poor pollination,
which is likely related to sub-optimal weather conditions for primary pollinating species in the
spring. Eastern Washington growers are challenged by cold temperatures and limitations to
current frost protection techniques.
Soils. Most of the soils in northwestern Washington were formed from parent material deposited
from the last glaciation period. Parent material may also be of marine, alluvial (moving water),
and lucastrine (still water) origin. Soil types supporting berry production in western Washington
include gravely, fine sandy, sandy, silty, silty clay, to clay loams. Blueberries can also be found
on heavier muck soils within the region. These heavier soils are from large mudflows resulting
from the past eruptions of Mount Rainier and Mount St. Helens, whereas the silts were blown in
by wind. Soils tend to be acidic due to high amounts of rainfall within the region, but will often
need modification for commercial production. In eastern Washington, much of the soils are
formed from weathered basalt and volcanic ash. The fertile soils of the Palouse and Columbia
Plateau were formed from loess (windblown silt). Large floods near the end of the last ice age
shaped much of the eastern Washington landscape and distributed loess further south in the state.
The pH of these soils tends to be high, requiring acidification for blueberry production. More
site-specific soil information can be found by accessing the USDA Natural Resources
Conservation Services Web Soil Survey at:
http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx.
Markets. Approximately 70% of the blueberry crop in Washington is processed, with the
remaining portion sold as fresh. Growers in western Washington report greater direct sales
relative to eastern Washington, with eastern Washington growers engaging in more wholesale
(Granatstein, 2014). Western Washington is also more processing intensive relative to eastern
Washington, while eastern Washington produces a greater portion of organic and fresh-market
fruit. Washington exports a large volume of fruit to the Pacific Rim and is continuing to explore
additional marketing opportunities in Asia. The Washington Blueberry Commission is one of the
major blueberry organizations that works cooperatively with other national and regional
3
commissions to promote blueberries in the market place. More information is available in the
panel presentation on marketing.
Cultivars and Ripening Seasons. ‘Duke’ is the primary cultivar grown in Washington State,
followed by ‘Bluecrop’, ‘Elliott’, ‘Draper’, and ‘Liberty’. ‘Reka’, ‘Legacy’, and ‘Aurora’ are
also cultivated on a commercial scale. Additional cultivars and species are grown on less acreage
throughout the state, including limited rabbiteye (V. virgatum syn. V. ashei Reade) production.
‘Duke’ is among the first cultivar to be harvested and can overlap with ‘Bluetta’ and ‘Earliblue’.
Harvesting for these cultivars can begin in late June to early July in eastern Washington and
early-to-mid July in western Washington. ‘Aurora’ is typically the last highbush cultivar to be
harvested and the harvest season may extend into September. For more information about
cultivars and approximate ripening times refer to the cultivar article in this publication and
Blueberry Cultivars for the Pacific Northwest (PNW 656).
OREGON
Production. Oregon’s blueberry production has increased tremendously in the last 10 years from
3,300 harvested acres in 2003 to 9,600 acres in 2013. This positions Oregon as third in harvested
blueberry acreage after Michigan and Georgia (NASS, 2014). However, when considering the
favorable growing environment, Oregon and Washington have the highest yields/acre despite
having a lot of immature acreage that is not yet yielding at full potential. Oregon and
Washington averaged about 9,200 lb/acre compared to 4,435 lb/acre for Georgia and Florida
(NASS, 2014). Average yields will likely increase in this region as acreage matures, but the rate
of increase will be slow if we continue to have new acreage planted. Oregon is known for having
some of the highest yields per acre of mature fields in the world.
The largest portion of Oregon’s blueberry production is located in the Willamette Valley.
However, there is significant production in the Umpqua Valley (around Roseburg), southern
Oregon (near Medford and Grants Pass), the Columbia Gorge (near Hood River), and in
northeastern Oregon (near Hermiston). There is also some commercial blueberry production on
the Oregon Coast, particularly near Langlois and Bandon in Coos and Curry Counties. Variation
in fruiting season is one of the largest advantages to having production in various regions of the
state – in southern Oregon, our earliest fruit is harvested. Production then progresses up the
Willamette Valley, to Hood River, and then to eastern Oregon. Our latest ripening fruit would
also follow this pattern, but some regions of Hood River and eastern Oregon would be
considered too cold (too short of a growing season – see below) for production of late ripening
cultivars, such as ‘Aurora’. The disease mummy berry (see Disease Management article) is less
prevalent in southern Oregon and perhaps in eastern Oregon based on grower experience. The
lower relative humidity found in eastern Oregon and some regions of southern Oregon reduces
disease pressure, particularly fruit rot in drip irrigated fields. The colder winters and hotter
summers found in eastern Oregon and some regions of southern Oregon may reduce the pressure
or management costs related to SWD (see Insect Management article). However, colder winters
and a shorter frost-free season may limit cultivar choices in these regions (see relevant sections
below).
4
Climate. Oregon’s climate is heavily influenced by the Pacific Ocean coastline, making up the
entire western border of the state and the Cascade Mountain range, just east of the Willamette
Valley. The movement of weather systems across the Pacific Ocean tends to result in milder
temperatures with limited seasonal extremes, including very few damaging weather events (i.e.
tornadoes, hailstorms, etc.). This is not to say that temperatures do not escalate or severely drop
at extreme elevations. Yet, the number of days in the Willamette Valley with temperatures over
90° F averages only six to eight days per year and temperatures below 0 ºF occur only once
every 25 years. Lowest recorded averages over the past thirty years for some key blueberry
regions are presented in Table 2. Blueberry flowers are sensitive to frost at about 28° F. The
probability (90%) of having frost free (28° F) days between spring and fall was calculated for
each region and averaged 210 days between the last day of 28° F in spring and the first 28° F in
fall in Aurora at the North Willamette Research and Extension Center. In contrast, the frost free
days in the other regions (at 28° F) were 195 days for Medford, 165 for Hermiston, and 150 for
Parkdale. Average climatological rainfall and temperature data for these regions are presented in
Table 2.
Table 2. Climatological data from western and eastern Oregon production regions.
Eastern Oregon
Parkdale
Hermiston
Western Oregon
Medford
NWREC
Air Temperature
Average min. (°F)
36.9
41.1
43.2
44.1
Average max. (°F)
61.0
64.5
67.9
63.4
Extreme min. (°F)
-13.0
-19.0
-4.0
-3.0
Avg. Total Precip. Per
34.1
9.9
18.4
42.5
Year (Inches)
*Temperature data averaged from 1981-2010 as calculated by the National Climatic Data Center. Weather data
provided by Kathie Dello, Deputy Director of the Oregon Climate Service.
Soils. Blueberry production in Western Oregon is typically established in many soil types
including Amity, Chehalis, Colquato, Jory, Malabon, Nekia, Willamette and Woodburn; some of
the better drained soils are Willamette and Woodburn which are common in blueberry
production as they occur in many regions of the Willamette Valley on the valley floor. Many
factors contribute to the formation of these soils. The eastern most side of the Willamette Valley
has a soil structure greatly influenced by the Cascade Range and as a result, is underlain by
volcanic rocks. The Coast Range on the western side of the valley is dominated by shale and
sandstone, rock types more susceptible to weathering and giving the range a more rounded
profile. However, regardless of prominent mountain range, most of the Willamette Valley is
overlain by a thin layer of clay beneath a surface of silts (Balster et al., 1968). These factors are
all greatly influenced by the Willamette River, along with the Missoula Floods that occurred
towards the end of the last Ice Age (O’Connor et al., 2001). All of this, combined with extreme
variations in geography and rainfall fluctuations, leads to a complex history of soil formation
with a multitude of parent materials and resulting pH’s, which should be adjusted to fall between
the desired blueberry production range of 4.5 - 5.5 (Hart et al., 2006; Huddleston et al., 1984).
Along with the USDA Natural Resources Conservation Services Web Soil Survey website
5
(http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx), UC Davis offers a similar
web app based off of google maps (http://casoilresource.lawr.ucdavis.edu/soilweb-apps)
with a slightly more user-friendly database.
Most of the blueberry plantings in the upper Hood River Valley are on Parkdale loam or Dee silt
loam soils. Most lower-valley plantings are on Hood loam or Oak Grove loam. These are
predominately moderately to well drained soils, with a depth of 60 or more inches to bedrock,
without any impermeable layers, and are slightly to moderately acidic. There are currently few
plantings in Wasco County, but these are on a Walla Walla silt loam, a deep soil, with slightly
acid surface and increasing alkalinity with depth. In eastern Oregon, soils are generally sandy
with a high pH – pre-plant modification of pH is insufficient for long-term production and thus
acidification of irrigation water used for blueberry production is required in this region.
In southern Oregon, finding good land is a challenge according to several growers. Soils found in
this region are often poorly drained; pre-plant preparation, including drain tile installation, is
critical. In addition, finding water in this region is a challenge as the best water sources are
rivers.
Markets. In 2013, approximately half (42 million lb) of Oregon’s blueberry production went to
fresh market. Oregon also contributes greatly to the amount of fruit that the US exports to
Canada and Asia. However, exportation is a very small portion of the overall US domestic crop
with only 3-4% being sold to international markets (Brazelton, 2013). Social media has also
increased awareness of local production and increased the information available to the public
about the health benefits, characteristics, and berry varieties available in Oregon. More
information is available in the panel presentation on marketing.
Cultivars and Ripening Seasons. Cultivars grown throughout the PNW are quite similar as
many northern highbush are broadly adapted (see Cultivar article). ‘Duke’ is the main early
ripening cultivar grown with the first harvest starting the last week of June in the Willamette
Valley. Production can begin earlier further south in the state and later in the Hood River Valley
and eastern Oregon. Other common northern highbush cultivars in established plantings or in
new plantings in Oregon in approximate order of ripening are ‘Bluegold’, ‘Bluecrop’, ‘Draper’,
‘Bluejay’, ‘Legacy’, ‘Liberty’, ‘Elliott’, and ‘Aurora’. ‘Legacy’ is part southern highbush and is
not recommended for colder regions of the State due to insufficient cold hardiness for consistent
production. Some rabbiteye cultivars are grown throughout the Willamette Valley and in the
Umpqua Valley for late fruit production (mainly for fresh market); cultivars include
‘Powderblue’, ‘Ochlockonee’, and ‘Titan’; these are also not recommended for the colder
regions of Oregon due to insufficient cold hardiness. For more information about cultivars and
approximate ripening times refer to the Cultivar article in this publication and Blueberry
Cultivars for the Pacific Northwest (PNW 656).
6
References:
Balster, C., and R. Parsons. 1968. Geomorphology and Soils, Willamette Valley, Oregon.
Accessed Jan. 29, 2015 at:
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/4291/SR%20no.%20265_ocr.pdf?s
equence=1.
Brazelton, C. 2014. World Blueberry Production Summary and Trends. Presentation at the 2015
Oregon Blueberry Conference on 27 Jan. 2015.
Brazelton, C. 2013. World Blueberry Acreage & Production. 2013 North American Blueberry
Council.
British Columbia Blueberry Council. 2014. BC Blueberry Press Release. Dec. 9, 2014. Accessed
on Jan. 28, 2015 at: http://www.bcblueberry.com/media/documents/media_
releases_2014/new_year--s_release_2015.pdf.
Geisler, M. 2013. Blueberries Profile. Agriculture Marketing Resource Center. Accessed Jan.
28, 2015 at: http://www.agmrc.org/commodities__products/fruits/blueberries-profile/.
Granatstein, D. 2014. Trends and Economics of Washington State Organic Blueberry
Production. Washington State University Extension Fact Sheet. In Press.
Hart, J., Strik, B., White, L. and Yang, W. 2006. Nutrient Management for Blueberries in
Oregon. Oregon State University Extension EM 8918.
Huddleston, J., and Kling, G. 1984. Manual for Judging Oregon Soils. 1984. Accessed online
Jan. 29, 2015 at:
http://depts.washington.edu/esrm311/Autumn%202014/Documents%202014%20Au/02_Oregon
%20Soil%20Judging%20Manual%20including%20Ch%203%20and%204.pdf
International Special Edition (ISE). 2014. Blueberries of the World 2014. Accessed online Jan.
28, 2015 at: http://www.freshfruitportal.com/wp-content/uploads/2013/12/blueberries
_of_the_world_2014.pdf.
National Agricultural Statistical Services (NASS). 2014. Noncitrus Fruits and Nuts 2013
Summary. Accessed online Jan. 22, 2015 at: http://www.usda.gov/nass/PUBS/TODAYRPT/
ncit0714.pdf.
NASS. 2014. 2013 State Agriculture Overview. Accessed online Jan. 29, 2015 at:
http://www.nass.usda.gov/Statistics_by_State/RFO/index.asp.
NASS. 2013. 2012 Quick Stats of Blueberries, Tame- Acres Harvested. Accessed online Jan. 29,
2015 at: http://quickstats.nass.usda.gov/results/5B2F595F-4F09-3FC2-88E6-253EDD4BBB3A.
7
NASS. 2012. 2011 Certified Organic Production Survey. Accessed online Jan. 22, 2015 at:
http://usda.mannlib.cornell.edu/MannUsda/ viewDocumentInfo.do?documentID=1859.
NASS. 2003. 2002 Quick Stats of Blueberries, Tame- Acres Harvested. Accessed online Jan 29,
2015 at: http://quickstats.nass.usda.gov/results/1F6F7749-CDAC-3213-94A8-399E880CFB67.
National Oceanic and Atmospheric Administration (NOAA). 1984. Narrative Summaries, tables
and Maps for Each State with Overview of State Climatologist Programs. Third Edition. Volume
2. Accessed Jan. 28, 2015 online at: http://www.wrcc.dri.edu/climate-narratives/.
O’Connor, J., Sarna-Wojcicki, A., Wozniak, K., Polette, D, and Fleck, R. 2001. Origin, Extent
and Thisckness of Quaternary Geologic Units in the Willamette Valley, Oregon. U.S. Geological
Survery Professional Paper 1620.
Schreiber, A. 2014. State of the Blueberry Industry. Presentation made by the director of the
Washington Blueberry Commission at the Washington Small Fruit Conference. 5 Dec. 2015.
Strik, B.C. 2014. Organic blueberry production systems – advances in research and industry.
Acta Hort. 1017:257-267
Strik, B., Finn, C., and Moore, P. 2014. Blueberry Cultivars for the Pacific Northwest. Pacific
Northwest Extension Publication. PNW 656.
8