Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

rrr s
epee Ot a —, .

anetiie Tas a

INTERMOUNTAIN FOREST & RANGE EXPERIMENT STATION
507 — 25th STREET, OGDEN, UTAH 84401

USDA Forest Service

» Research Note INT-195 \ - June 1975
~ WINTER STORAGE AND PACKAGING So = c
EFFECTS ON LUCKY PEAK SEEDLINGS EEN - -- .
iM ie_< al<s2. lc...) os ; = ioe
Frank E. Morby and Russell A. Ryker! ~ ES
4 m ‘
ABSTRACT =

Stx spectes of seedlings from nine different Lucky Peak Nursery
seed lots were lifted tn November and stored for the winter at both
28° and 33° F in both bag and crate packages. Initial survival and
growth of study seedlings planted in the Botse, Payette, Sitgreaves,
and Lincoln Nattonal Forests were compared with rates for seedlings
from the same lots planted after conventional spring lifting. Results
tndtcate that winter storage ts generally feasible, but the best
packaging method and lifting season differ with spectes. No advantage
was gained by storing seedlings at the subfreezing 28° F temperature.

Several considerations make the feasibility of fall seedling lifting and winter
storage important in the area served by Lucky Peak Nursery, Boise, Idaho.

National Forests in Arizona, New Mexico, and southern Utah experience optimal
planting conditions in February or early March. Soils then dry rapidly, and prospects
for seedling survival quickly decline. Weather and soil conditions at Lucky Peak Nursery
seldom permit seedling lifting and delivery before mid-March.

The Boise and Payette National Forests in Idaho are evaluating fall lifting and
planting of nursery stock as a means of increasing the efficiency of reforestation
programs. Lucky Peak Nursery can regulate soil moisture to provide excellent lifting
conditions in the fall, resulting in less seedling root damage than occurs with spring
lifting. However, early storms at times prevent the completion of fall planting and
some stock must be destroyed.

lRespectively, Nurseryman, Lucky Peak Nursery, Boise National Forest, Boise,
Idaho; and Research Silviculturist, Intermountain Forest and Range Experiment Station,
Ogden, Utah 84401, stationed in Boise, Idaho.

aa
\p

Mb rinaaty | my

os
Fo
‘
g
’
1
i
’
i
i La
i
i
‘ _.
7 —
5
.
4
' le ‘
'
:
4 *
~
r
2,
j we jt

Oe nde Lg yey emcgun:

(i. ws

yt 10
; a
dost ae

UY oe sist 0) oF!
cet epoca fi
yes eG” | Ae

If seedlings could be lifted in the fall and successfully stored during winter,
some forests could hold unused fall planting stock for spring, other forests could
receive trees for planting at the optimal time, and the nursery would have greater

; flexibility in scheduling lifting operations.

Stock lifted in the spring at Lucky Peak Nursery normally is stored at 33° F.
To minimize molding and metabolic activity, others (Hocking and Nyland 1971; Hocking
and Ward 1972) have stored trees at subfreezing temperatures. The results indicated
that the lower temperature may be better for a long winter storage period, providing

»the below-freezing conditions do not damage the trees.

? Both bags and crates have been used successfully to package spring-lifted stock.
We were interested in comparing bag and crate storage to determine if desiccation
occurs in crated seedlings at subfreezing temperatures.

The primary objective of this study was to determine if fall-lifted seedlings
“stored at 28° or 33° F will survive and grow as well as spring-lifted seedlings handled
by standard procedures. A secondary objective was to determine if packaging methods
(bags, crates) influence the survival and growth of seedlings subjected to the differ-
/ent lifting schedules and storage regimes.

METHODS
In November, 1972, after an oscilloscope trace indicated dormancy, we lifted
.(fig. 1) 1-0 ponderosa pine (Pinus ponderosa Laws.), 2-0 lodgepole pine (Pinus contorta
Dougl.), 2-0 Douglas-fir (Pseudotsuga menztesii var. glauca (Beissn.) Franco), and
3-0 Engelmann spruce (Picea engelmannti Parry) from stock scheduled for planting on the
Boise National Forest; 2-0 ponderosa and 1-0 western larch (Larix occidentalis Nutt.)

Figure 1.—Study seedlings
were lifted in November
* at Lucky Peak Nursery.

Figure 2.--Seedlings
were packaged root-
to-root in crates.

from stock scheduled for the Payette National Forest; 2-0 ponderosa pine from stock
scheduled for the Sitgreaves National Forest, Arizona; 2-0 ponderosa pine from stock
scheduled for the Lincoln National Forest, New Mexico; and 1-0 bitterbrush (Purshia
tridentata (Pursh) DC.) from stock scheduled for the Idaho Fish and Game Department
to be planted within Boise National Forest boundaries.

The use of an oscilloscope to determine seedling dormancy is a recent research
development. Manuscripts are being prepared describing the technique, which has proven
successful in numerous field tests.

Half of each lot of trees and shrubs was packaged in bags and half in crates on
the day the seedlings were lifted. Crates were 22-1/2 inches long, 16 inches wide,
and 7-1/2 inches deep. A 24-inch strip of Fibreen 200,* a waterproofed and fiber-
reinforced kraft paper, was used to line the crates. A 1-1/2- to 2-inch layer of clean,
well-moistened sphagnum moss covered the paper and alternate layers of moss and seedlings
were placed into crates. The seedlings were placed root to root (fig. 2) in the approx-
imate center of the crate. A final 1-1/2- to 2-inch layer of moist sphagnum was placed
over the roots of the top layer of seédlings and the waterproof paper was gathered at
the ends and rolled tightly. The crates were closed with four wire catches.

The seedling bags were 24- by ll- by 35-inch three-ply kraft paper with an inner
layer of polyethylene that forms a moisture barrier. Two large handfuls of well-
moistened sphagnum moss were placed in the center of the bottom of the seedling bag.
Seedlings were placed in layers with roots over the moss. Two large handfuls of moss
were used to cover the roots of the top layer of seedlings. The bag (fig. 3) was
closed and rolled tightly to expel the air. The rolled seal was then taped with four
strips of l-inch nylon reinforced tape.

Considerably more sphagnum was used in crate packaging. One thousand seedlings
packed in crates weigh 20 to 25 pounds more than equivalent seedlings packaged in bags.

.

2 The use of trade riames in this publication is solely for the convenience of the
reader. Such use does not constitute an official endorsement by the U.S. Department of
Agriculture of any product or service to the exclusion of others that may be suitable.

Half of each lot of packages was placed in refrigerated storage maintained at
28° F. The other half was placed in storage maintained at 33° F. Relative humidity
varied between 52 and 69 percent in 28° F storage and between 85 and 92 percent in
33° F storage (fig. 4).

All spring-lifted stock was lifted during the period February 16 to March 28,
1973 (table 1). The lifting was done routinely except that seedlings for the study
were taken from seedbed areas immediately adjacent to the fall 1972 study seedling
lift areas. Thus, essentially the same soil and site characteristics prevailed for
both fall- and spring-lifted seedlings of each stock.

The storage period at the nursery was not the same for all stock. Table 1 indicates
both nursery and field storage periods. Because all seedlings for the Boise and Payette
National Forests and the Idaho Fish and Game Department were held at the nursery until
plantins time, the seedlings stored at 28° F were placed in 33° F storage on April 2,
and held at that temperature until shipped.

Pigure 4.--Packaged seed-
lings were placed in-
refrigerated storage
at 28° and 33° F.

Table 1.--Lifting, storage, and planting schedules for seedling lots used in the study

Fall-lifted : Spring: lifted
: : : Days from: : Days fron
Date =: Date : i aye in : shipment : Date : Days in : shipment
planted . lifted: nursery: until : lifted; nursery: until

Cooperator : Species - Age class.

1973 1972 : storage ; planting 1973 :storage - planting
Boise N.F, Ponderosa pine 1-0 5/8 11/13 171 5 3/28 3% 5
Boise N.F. Lodgepole pine 2-0 5/8 11/13 171 S 3/6 58 5
Boise N.F. Douglas-fir 2-0 5/8 11/13 Wl 5 3/7 57 5
Boise N.F. Engelmann spruce 3-0 5/8 MY bs 171 5 3/6 38 =
Payette N. ER. Ponderosa pine 2-0 5/17 11/13 185 0 3/19 $9 0
Payette N.F. Western larch 1-0 5/18 11/13 185 1 2/16 $0 1
Sitgreaves N.F. Ponderosa pine 2-0 5/22 11/6 1355 64 3/12 7 64
Lincoln N.F. Ponderosa pine 2-0 4/4 11/8 100 47 3/13 0 21
Idaho Fish & Game Bitterbrush 1-0 4/25 11/13 163 0 2/16 68 0

After the seedlings left the nursery, the stock handling, site preparation, and
planting procedures and site conditions varied among cooperators. Therefore, the
field plantings should be considered as separate experiments for each stock. The
experimental design for all was randomized block with three replications. Each plot
contained 50 planted seedlings. Selected comparisons among treatment means were made
using a sequential method (Snedecor 1956, p. 253).

BOISE STOCK

From May 4 to May 8, 1973, plots for each species shipped to the Boise National
Forest were completely cleared to mineral soil using handtools. All stock was removed
from the nursery 33° F storage on May 3, 1973, and transported to the planting site.
Temperatures within the root zone of the seedlings in the crates held at 36° F during
transporting. At the planting site the stock was placed in cool shade, covered with
a light colored tarp, and permitted to reach ambient air temperature before auger plant-
ing on May 7 and 8, 1973. The planting was done by a team of two augermen and six
planters. Fifty 4- by 14-inch holes were bored in each plot ahead of the beg oe

The planting site was on granitic soil at an elevation of about 5S, 000 feet. ‘The
ponderosa pine and Douglas-fir were planted on a south aspect, the lodgepole pine on
an cast aspect, and the Engelmann spruce in a cove.

Approximately three-fourths inch-of rainfall was received during and just after
planting. The growing season was normal, with little precipitation during July and
August. There were no extended periods of hot weather.

First-year survival and growth measurements (table 2) were taken Septenber 11.

Table 2.--Mean survival and height growth, and statistical significance! for the four seedling lots
planted on the Boise National Forest

: : Ponderosa pine : Lodgepole pine _: Douglas-fir ee spruce
Time of : Storage : : :Height : : Height : = ae =: Beigtt

Lifting : temperature : Package : Survival : growth Survival : growth :Survival : growth: Survival? - h
°F Percent Cm Percent Cm Percent Ca Percent cz

Fall 28 Bag 98 a Vesna 100 a 9.8 a 7S a 6.3 a 95 4.6 a
Fall 28 Crate 90 b 5.9 b 88 b 4.0,b S7 b 4.3b 83 54 c
Fall 33 Bag 100 a Hel ea 100 a 9.6 a 90 a T eee 93 4.7 a
Fall 33 Crate 98 a 6.5 ab 98 a 1}).2,2 76a 7.4 a 9 4.9 a
Spring 33 Bag 98 a Ee) (ec 96 a 10.2 a 96 a 3.7 b 97 3.9 be
Spring 35 Crate 98 a 5.6 be 100 a 9.4 a 93a 3.2 b 97 4.4 2b

1 In each column of the table, all means followed by the same letter do not differ significantly at the
95 percent confidence level.

“ Analysis of variance revealed no significant differences between treatments for survival, at the
95 percent level, so we chose not to make a comparison between means.

5

PAYETTE STOCK

During late summer and fall of 1972 the Payette National Forest planting sites
were prepared using a medium-size bulldozer with a brush-piling or land-clearing blade.
The majority of the site was completely cleared to mineral soil.

All stock was removed from the nursery 33° F storage on May 17, 1973, and trans-
ported during the early morning hours in an insulated container. The 2-0 ponderosa pine
was removed from the transporting container and placed in cool shade. Trees were
auger-planted by a team of one augerman and three planters, alternately planting behind
the auger. The auger holes were approximately 4 by 14 inches. The planting site is
an east-facing slope with basaltic soils that are 15 to 30 inches deep with some broken
rock. The elevation is 5,500 feet. Precipitation during the growing season was below
normal and mean maximum temperatures for May, June, July, and August were slightly
above normal.

The 1-0 western larch was removed from nursery storage on May 17, 1973, transported
to the planting site, and held overnight at approximately 40° F. Trees were auger-
planted on May 18, There were six planters in the planting crew. The planting site
was on an east-facing, 2-percent slope with granitic soil 18 inches deep. The weather
during the growing season was warmer than normal, with less rainfall.

First-year survival and growth measurements (table 3) were taken for the pine
on September 6, and for the larch on October 2.

Table 3.--Mean survival and height growth, and statistical significance! for
the two seedling lots planted on the Payette Nattonal Forest

: : : Ponderosa pine - Western larch

Time of : Storage : : : : :

lifting : temperature: Package : Survival : Height growth: Survival? : Height growth?

of Percent Cm Percent Cm

Fall 28 ; Bag 100 a 5.8 95 19.5

Fall 28 Crate 64 b 3.4 99 TSO

Fall 33 Bag 100 a‘ 6.3 93 17.9

Fall 33 Crate 88 a 5.0 98 1-09
Spring 33 Bag 100 a 6.0 97 , 17.6
Spring 33 Crate 98 a 525 96 od,

1 In each column of the table, all means followed by the same letter do not
differ significantly at the 95 percent confidence level.

2 analysis of variance revealed no significant differences at the 95 percent
level, so we chose not to make a comparison between means.

SITGREAVES STOCK

The fall-lifted stock for the Sitgreaves National Forest was held in nursery
storage at the assigned temperatures until March 19, 1973, when it was removed and
shipped in a refrigerated van (33° to 34° F)to the planting site. The spring portion
of the stock was lifted on March 12, 1973, and stored at 33° F until it was shipped
with the fall stock. ;

The stock was received at the planting site on March 21, 1973. Trees were stored
in a snow cache. No temperature or humidity readings were taken. The planting site
was a flat ridgetop with cobbly loam soils. Because of an unusually wet year, planting
was delayed until May 21 and 22, 1973. Trees were planted by a crew of three using
planting bars. Each crew member planted one block. There was a late, wet spring,
summer rains were below normal, and the fall months were dry.

First-year survival and height growth (table 4) were measured September 18.

Table 4.--Mean survival and height growth for ponderosa pine
planted on the Sitgreaves National Forest}

Time of =: Storage : : :
lifting: temperature ; Package ; Survival ; Height growth
°F Percent On
Fall 28 Bag 58 SoZ
Fall 28 Crate 70 4.4
Fall 35 Bag 52 Bo
Fall 33 Crate 76 4.0 Z
Spring 33 Bag 62 4.0
Spring 3535 Crate 50 555

1 analysis of variance revealed no significant differences at the
95 percent level.

LINCOLN STOCK

The fall-lifted stock for the Lincoln National Forest was held in nursery storage
at the designated storage temperatures until February 16, 1973, when it was removed and
shipped on a refrigerated van (33° to 34° F) to the planting site. The stock was ae
received on February 18, and stored in a refrigerated van at 33° to 40° F and 90 percent
humidity until planted.

On March 13, 1973, the spring portion of the study stock was lifted, packaged,
and shipped via airfreight the same day.

The planting site is on a ridgetop with a slight northeast aspect. Soils are
generally dry loam with varying amounts of limestone rock. The elevation is 7,050
feet. The planting blocks were completely scalped of all vegetation before planting.
As on the Sitgreaves Forest, planting was delayed until March 30 and April 4, 1973,
by wet weather. The planting was done by a six-man crew. A 4-inch auger was used
to bore planting holes approximately 4 by 14 inches. During planting there were cold
temperatures with high humidities. Moisture received during the growing season was
normal for April and May, but less than normal for the balance of the season. Tempera-
ture and humidity were normal for the growing season.

First-year survival and height growth (table 5) were measured September 17, 1973.

Table 5.--Mean survival and hetght growth, and statistical significance}
for ponderosa pine seedlings planted on the Lincoln Nattonal

Forest
Time of -: Storage : : 5
lifting =: temperature: Package _: Survival: Height growth?
or Percent Cm
Fall 28 Bag 10 c 5.0
Fall 28 Crate (3) (3)
Fall 55 Bag 48 b Sy!
Fall 33 Crate 70 ab 5.6
Spring 33 Bag 88 a a55
5.8

Spring 33 Crate 90 a ;

1 In each column, all means followed by the same letter do not
differ significantly at the 95 percent confidence level.

2 Analysis of variance revealed no significant differences at the
95 percent level, so we chose not to make comparisons between means for
height growth.

3 These seedlings were inadvertently removed from storage and mixed with
nonstudy stock.

BITTERBRUSH STOCK

The bitterbrush stock provided for the Idaho Fish and Game Department was planted
and measurements were made by Robert B. Ferguson, Wildlife Biologist, Intermountain
Forest and Range Experiment Station. It was stored in the same manner as the Boise
and Payette National Forest tree seedling stock. The spring stock was lifted and stored
on February 16, 1973. All of the seedlings were removed from storage and planted
on April 25, 1973. Individual 2- by 3-foot planting plots were scalped using a wheel
tractor with terracing blade on a 3-point hitch. Planting was done by four planters
using planting spades. The sites were south-facing slopes with granitic soil at an
elevation of about 3,200 feet. The growing season was dryer and warmer than normal.

First-year survival was measured September 10, 1973 (table 6). Because of the
difficulty in identifying new growth on bitterbrush, first-year height growth was
not measured, .

Table 6.--Mean survival and statistical significance}
for bitterbrush nursery stock

Time of : Storage = :
lifting 7 temperature : Package : Survival
oF Percent
Fall 28 Bag 70 ab
Fall 28 Crate 44 b
Fall 33 Bag 84 a
Fall 33 Crate 68 ab
Spring 33 Bag 92 a
Spring : 33 Crate 98 a ;

1In each column, all means followed by the same letter
do not differ significantly at the 95 percent level.

8

ey lbere

es

SUMMARY OF RESULTS

There were no significant statistical differences in first-year survival or height
growth between crated and bagged spring-lifted trees. This also was true for fall-
lifted trees, except for crated trees stored at the subfreezing temperature (28° F).
This storage greatly reduced survival and growth of most of the seedling lots tested.

With the exceptions of the crated seedlings stored at 28° F and the ponderosa pine
stock planted on the Lincoln National Forest, there were no significant differences in
survival between fall-lifted and spring-lifted trees. However, height growth of some
stock does appear to be affected by season of lifting. The first-year height growth of
ponderosa pine and Douglas-fir was greater for fall-lifted than for spring-lifted trees.
Lodgepole pine and Engelmann spruce trees, however, showed almost the same growth for
both lifting seasons.

Table 7 presents a ranking according to a scale of arbitrary success values for
the various species, lifting seasons, storage temperatures, and packages.

When planting on the Boise and Payette National Forests, we can expect acceptable
tree seedling survival when any of the lifting, storage, and packaging techniques
studied are used, except fall lifting and storage in crates at 28° F. For bitterbrush,
spring lifting should be practiced when possible but, if necessary, seedlings can be
lifted in the fall and stored at 33° F in bags.

None of the techniques studied resulted in good survival on the Sitgreaves or
Lincoln National Forests. The precise reasons for the poorer survival and growth of
these seedlings are unknown. Because they were lifted and handled in the same way as
all other seedlings, we assume these trees were in equally good physiological condition
when they were shipped from the nursery. However, there were more opportunities for
adverse conditions to occur during shipment and local storage than for seedlings shipped
to the Boise and Payette National Forests. The elapsed time from lifting to planting
was about the same for all forests, but the periods of local storage on the Sitgreaves
and Lincoln National Forests were much longer. Of course, the sites also were different
from the central Idaho sites. Because of the success of fall lifting and winter storage
in Idaho, it seems advisable to make another test of the Sitgreaves and Lincoln National
Forest ponderosa pine with more detailed monitoring of the conditions between shipping
and planting. Survival and height growth will be measured for two more growing seasons,

Table 7.--Comparative ranking! for each nursery seedling lot tested, based on first-year survival

= : Sitgreaves: Lincoln
Boise NF : Payette NF : NF : NF

: : : Ponderosa: Lodge-: Engel- : Ponderosa : : Ponderosa : Ponderosa:
Time of - Storage : > pine, : pole :Douglas-: mann : pine, ; Western: pine, : pine, : Bitter-

lifting :temperature : Package: 1-0 ine fir sspruce: 2-0 larch : 2-0 : 2-0 brush
oP
Fall 28 Bag G G A G G G NA NA NA
Fall 28 Crate A A NA A NA G NA (2) NA
Fall 33 Bag G G A G G G NA NA A
Fall 35 Crate G G A G a A G A NA NA
Spring 33 Bag G G G G G G NA A G
Spring 33 Crate G G G G G G NA A G
1 Greater than 90 percent survival --- Good (G)
75-90 percent survival ------------- Acceptable (A)
Less than 75 percent survival ------ Not acceptable (NA)

2 These seedlings were inadvertently removed from storage and mixed with nonstudy stock.

LITERATURE CITED

Hocking, Drake, and Ralph D. Nyland. oe
1971. Cold storage of coniferous seedlings. AFRI Res. Rep. 6. Appl. For. Res. 32
Inst., Coll. For., Syracuse Univ. ;

Hocking, Drake, and B. Ward.
1972. Late lifting and freezing in plastic bags improve white spruce survival
after storage. Tree Planters' Notes 23(3) :24-26.

Snedecor, George W.
1956. Statistical methods. 5th ed., 534 p. Iowa State Coll. Press.

U.S. FORESMERY
CENTENNIAL

10

*U.S.GOVERNMENT PRINTING OFFICE: 1974 677-097 / 56 REGION NO. 8