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
Harvesting – Hand vs. machine
Bernadine Strik1, Paul Norris2, Frank Brown3, Doug Khramer4
1
Introduction & moderator; Dept. Horticulture, Oregon State University
2
Norris Blueberry Farm, Roseburg, Oregon
3
Littau Harvesters Inc., Stayton, Oregon
4
Berries Northwest, Oregon
Many blueberry cultivars are adapted to machine harvest as well as hand harvest (see Cultivar
article/presentation). Historically, hand-harvested fruit has been marketed for fresh and
processed markets whereas all machine-harvested fruit were destined for processed markets.
However, with higher labor costs and shortage of sufficient labor at key times during the season,
there has been some machine harvest of fruit for fresh market since the mid-2000s. The members
of this panel will discuss their experiences in managing labor for high-quality hand-picked fruit
and labor needs. Cultural modifications and considerations for maximizing efficiency of machine
harvest have been mentioned in other presentations during the School, but may be further
stressed here. In addition, good management practices for maximizing quality of machineharvested fruit and proper use of over-the-row machine harvesters will be covered.
While machine harvesting for fresh market is being done in the Pacific Northwest with some
varieties and by some growers, the fruit may not be suitable for longer distance markets as it has
a shorter shelf-life. Some packers may pay less for machine-picked fruit than for hand-picked
fruit (for fresh market). While the cost of harvesting is less for machine-picking than for handpicking, the returns may also be lower (e.g. higher management costs, more fruit loss, less yield).
It is also not typical to fully machine harvest a bush for fresh market – due to timing of fruit
ripeness (e.g. the first ripe fruit of ‘Duke’ may need to be hand-picked to get best early-season
price).
Hand harvest
In the Northwest hand-harvest is primarily done by resident and migratory Latino workers,
predominantly from Mexico. Smaller farms may have local pickers or use U-pick to harvest the
majority of their fruit. On average, 5 to 20 people per acre, depending on planting age and
cultivar (yield and length of harvest season) will be needed to pick fruit. Responsible picking
crew supervisors should be hired to oversee individual pickers. As record keeping regulations
have increased, progressive growers have begun using bar code scanners to record pickers’
names, pounds picked, and hours worked (for Social Security and industrial insurance). Pickers
must make minimum wage, but many earn considerably more per hour. Prospective pickers must
be trained to ensure harvest of high quality fruit.
As blueberries do not ripen uniformly on the plants, multiple harvests are required. Most of the
common cultivars can be picked clean in two to three harvests spaced 7 to 14 days apart
depending on cultivar and climate. Choosing when to start the first harvest can be tricky.
75
After a rain, wait until the bushes have dried off before harvesting. Handling fruit when it is wet
will lead to a loss of the surface wax (bloom) and an increase in decay.
Most growers have pickers harvest into buckets and then fruit are sorted in the packing
shed/plant.
Machine harvest
Not all fields can be mechanically harvested, as the rows need to be straight and there needs to
be sufficient room to turn the machine at the end of each row (headlands – see site establishment
presentation). Generally 10- to 11-foot rows and 25-foot headlands are needed to maneuver the
machine and minimize losses. Ground with a slope in excess of 10% presents difficulties. Plants
are best pruned to a narrow crown from a young age to improve the fit of the catcher plates and
reduce ground losses. A simple trellis will also reduce ground losses. Growing plants on raised
beds, that fit into the “boot” of the machine, will place the catcher plates lower down on the
crown, also minimizing losses. Good pruning is necessary to maximize fruit recovery and
minimize junk (broken old wood).
In the Northwest, mechanical harvesters are either purchased or leased/rented for the harvest
season from machine manufacturers, or growers can hire custom harvesters.
In the past 20 years, design engineers and manufacturers have made significant strides in
improving self-propelled, over-the-row mechanical harvesters. This has greatly improved
recovery of fruit, reduced bruising, and reduced breakage of the plant (reducing current and next
year’s yield). Most harvesters used today are rotary harvesters with nylon rods (“fingers” or
“beaters”).
Machine harvesters must have a good operator as there are many things that affect the quality of
the harvested fruit that can be controlled on the machine – these include machine harvester
ground speed, centering the machine on the row, beater speed (rpm of the fiberglass rods), and
beater amplitude (range of movement, affected by weights on the rotary heads). In addition to
ensuring the planting is well-designed, the plants must be pruned well and irrigation, disease, and
insect management must be excellent to get a good quality product (for processing or fresh, if
possible, with the cultivar grown).
Losses to machine harvest (from total yield) include: 1) drop on the ground (typically 20 to 25%
without a trellis in mature plantings over the season, but 10 to 15% with a trellis); 2) green fruit
or immature fruit that comes off during harvest; 3) reduced yield in the current season due to
breakage of branches or laterals (often drop to ground or are blown out by the fan); and 4)
damaged canes (near catcher plates) or broken branches reducing next year’s yield. Since the
losses are generally less when hand-picking (~ 5 to 10% ground drop, depending on crew
supervision and cultivar), total yield for a 100% machine-picked field will be lower than a
similar aged/managed field that is hand-picked for the same cultivar.
With a properly adjusted and operated machine harvester, the right cultivar, and exceptional
management of the field, growers may be able to machine pick some of the harvests and sell the
76
fruit fresh. However, machine-harvested fruit for the fresh market should generally be marketed
quickly as it has a shorter shelf-life than hand-picked fruit. Often machine harvesters are used to
“clean up” the later pickings – this fruit is then processed.
To further improve fruit quality when machine harvesting, pick the fruit at the coolest times of
the day, such as early morning and late evening, or all night if conditions allow for it. Also,
install a canopy on the harvester to reduce the temperature of the harvester deck and cleaner
systems.
Postharvest Handling
Good handling practices are important for hand- and machine-picked fruit.
There are many opportunities for field bruising after the berries have been picked. If blueberries
are picked into buckets in the field for later transfer to a processing flat, be sure to instruct field
staff not to over-fill flats. Compression damage will result and poor cooling will occur if flats
contain too many berries. Instruct truck and trailer loaders to use care when handling flats so as
not to jar or drop them. Drivers should proceed slowly over rough roadways; be sure truck
suspension systems are fully functional.
Protecting berries from heat deterioration begins in the field. Filled flats should never be left
exposed to the sun because the fruit temperature can rise above the air temperature in less than
an hour. Flats left in the shade will have fruit temperatures as much as 10°F lower than the
ambient air temperature. If there is a long delay between harvest and transfer to packing shed or
processor, at the very least, place a light-colored tarpaulin over the flats and periodically wet it
down to provide evaporative cooling. These recommendations pertain to processed as well as
fresh market fruit. For fresh market fruit, however, it is very important to get the fruit to a
location where it can be completely chilled using forced air cooling as soon as possible. Some
additional suggestions for improving fruit cooling include using refrigerated vans to store crates
and fruit. Storing and chilling crates before and after harvest can significantly reduce fruit
temperature, increasing shelf life. Also, there is now in-field chilling equipment available (e.g.
the new “COLD PICK” system) which may further improve shelf-life.
77