National Tree Seed National Tree Seed LaboratoryLaboratory

United StatesUnited States Distribution of Distribution of

JuniperusJuniperus J. pinchotii

J. virginiana

J. monosperma

J. scopulorum

J. silicicola

United States Distribution of

Juniperus

Western Junipers

J. osteosperma

J. deppeana J. communis

J. ashei

USDA Forest ServiceUSDA Forest Service National Tree Seed LaboratoryNational Tree Seed Laboratory

Seed Testing Data 2002-1962Seed Testing Data 2002-1962TotTotal al

GerGermm

MeaMean n

GerGermm

MeaMean n ViabViabilityility

FullFull Wet Wet wt. wt.

%% Seeds/Seeds/

SpeciesSpecies No.No. No.No. %% %% SeeSeed %d %

MC MC %%

PuritPurityy

kgkg

J. J. monospermamonosperma

33 22 3939 7676 9898 .. .. ..

J. pinchotiiJ. pinchotii 2121 99 1212 .. 4242 13.213.2 100100 30,61630,616

J. J. scopulorumscopulorum

113113 3131 1212 6464 8181 9.29.2 99.399.3 60,07460,074

J. silicicolaJ. silicicola 77 77 1010 .. 5353 11.911.9 99.399.3 97,78497,784

J. virginianaJ. virginiana 489489 323323 4141 7171 7878 8.48.4 95.895.8 136,65136,6511

JuniperusJuniperus Seed Collection Seed Collection ProblemsProblems

• Native seed collections contain many Native seed collections contain many empty seedempty seed

• Unpredictable and variable seed Unpredictable and variable seed crops due to harsh weather crops due to harsh weather conditions conditions

• Seed maturation periods vary by Seed maturation periods vary by species- immature and mature seed species- immature and mature seed easily mixed together during easily mixed together during collection collection

• Western species in remote areas-Western species in remote areas-inaccessible for easy collectioninaccessible for easy collection

• Equipment for removal of empty and Equipment for removal of empty and low vigor seed not affordable by all low vigor seed not affordable by all processorsprocessors

J. scopulorumJ. scopulorum Seed CleaningSeed Cleaning

at Big Sioux Nursery, South Dakotaat Big Sioux Nursery, South Dakota • 10-15% first year green berries in field 10-15% first year green berries in field

collectioncollection• Green berries will not float outGreen berries will not float out• Fanning mill to remove green berriesFanning mill to remove green berries• 5% green berries left after cleaning5% green berries left after cleaning• 10% empty seed10% empty seed• 60-70% germination in nursery bed60-70% germination in nursery bed• Plant seed in July Plant seed in July • Plant seed near irrigation lines to keep Plant seed near irrigation lines to keep

seed moist before winterseed moist before winter• Do not let seed dry outDo not let seed dry out

J. scopulorumJ. scopulorum seed cleaning seed cleaning USDA Bridger Plant Materials USDA Bridger Plant Materials

Center, MontanaCenter, Montana• Mascerate berries- line with abrasive material for Mascerate berries- line with abrasive material for

better pulp removal better pulp removal • Use lye or citrus soap for softening pulp (1.3 Use lye or citrus soap for softening pulp (1.3

ml/liter of lye); 4.9ml of citrus soap to 1.4 kg ml/liter of lye); 4.9ml of citrus soap to 1.4 kg berries berries

• 1.8 to 4.1kg berries = .45kg clean seed1.8 to 4.1kg berries = .45kg clean seed• Household blender with taped blades for small lots Household blender with taped blades for small lots • Empties float in waterEmpties float in water• Germination ½ of viability percentGermination ½ of viability percent

• Best germination with 45 minutes HBest germination with 45 minutes H22SOSO44 soak + soak + 116 day warm + 150 day cold, moist stratification116 day warm + 150 day cold, moist stratification

• Check for filled seed on tree before collectionCheck for filled seed on tree before collection

JuniperusJuniperus Seed Germination Seed Germination ProblemsProblems

• Complex dormancies- embryo, Complex dormancies- embryo, endosperm, secondary dormancyendosperm, secondary dormancy

• Long stratification periods- vary Long stratification periods- vary warm and cold cycles warm and cold cycles

• Seed viability much greater than Seed viability much greater than germination percentagesgermination percentages

• Germination unpredictable in Germination unpredictable in laboratory and nursery laboratory and nursery

• Seed sources may respond Seed sources may respond differently to stratification differently to stratification treatments due to introgressiontreatments due to introgression

• Wildland seed viability – 22 to 35%Wildland seed viability – 22 to 35%

Juniperus scopulorumJuniperus scopulorumColorado State Forest Nursery Colorado State Forest Nursery

(bareroot seedlings)(bareroot seedlings) • Sow seed in nursery Sow seed in nursery

beds late July- soil beds late July- soil temperature @ 21°Ctemperature @ 21°C

• Frost fabric on nursery Frost fabric on nursery beds- raised beds- raised temperature 3°Ctemperature 3°C

• Use winter irrigation to Use winter irrigation to prevent seed prevent seed dessicationdessication

• 2-0 bareroot, 2-1 2-0 bareroot, 2-1 container transplantscontainer transplants

• Tarpaper container Tarpaper container used for transplantsused for transplants

seedlings in shadehouse

Seed treatment for container seedlings

of J. scopulorum Colorado State Forest Nursery

• Bury J. scopulorum seed in nursery bed in summer, extract in February

• 70% cracked seed coats, radical emerging

• Greenhouse sowing in February

• Harden off in late July in shadehouse

• Still growing in September & October

soil temperatures at 10 cm

22 2116

72

-1 -2-5

0

5

10

15

20

25

Jul Aug Sep Oct Nov Dec Jan

Date

Temp

eratur

e (C)

Juniperus scopulorumJuniperus scopulorum Seed Study Seed Study USDA National Tree Seed LaboratoryUSDA National Tree Seed Laboratory

• Weight affects mean viability, number of dead, percent empty seeds

• Gravity table increases viability by redistributing seed in seedlot

• Heavy seed has the best viabiltiy

Gravity Table Effect on Viability and Empty Seed

80 77

65

53

19 22

33

44

0

10

20

30

40

50

60

70

80

90

Heavy Medium Light Trash

Seed Weight

Av

era

ge

Gravity Table viability Mean dead

Viablity before table Percent empty

J. scopulorum germination study

National Tree Seed Laboratory Best TreatmentsBest Treatments LaboratorLaborator

y y germinatigerminationon

Oklahoma Oklahoma State State Nursery Nursery germinatiogermination n

3 day water soak, 16 wks cold, 3 day water soak, 16 wks cold, 9 wks warm, 9 wks cold9 wks warm, 9 wks cold

Germination Germination in in stratificatiostratificationn

81.75%81.75%

3 day water soak, 16 wks 3 day water soak, 16 wks warm, 13 wks coldwarm, 13 wks cold

55%55% 29.25%29.25%

4 day water oak, 12 wks warm, 4 day water oak, 12 wks warm, 13 wks cold13 wks cold

49%49% 14.5%14.5%

3% hydrogen peroxide 90 3% hydrogen peroxide 90 minute soak, 8 wks warm, 13 minute soak, 8 wks warm, 13 wks coldwks cold

45%45% 20%20%

6 day 10.000 ppm citric acid 6 day 10.000 ppm citric acid soak, 6 wks warm, 10 wks cold soak, 6 wks warm, 10 wks cold

22%22% 24.25%24.25%

Juniperus virginianaJuniperus virginiana Eastern redcedar Seed Eastern redcedar Seed

TreatmentsTreatments • 24 hour water soak, 30 24 hour water soak, 30

day warm moist, 90 day day warm moist, 90 day cold moist used in cold moist used in NebraskaNebraska

• 96 hours citric acid soak 96 hours citric acid soak (10,000 ppm), 6 weeks (10,000 ppm), 6 weeks warm moist (24°C), 10 warm moist (24°C), 10 weeks cold moist (5°C)weeks cold moist (5°C)

• Best germination Best germination temperature 15°Ctemperature 15°C

• Secondary dormancy Secondary dormancy induced above 15°Cinduced above 15°C

• Seeds heavier than water Seeds heavier than water had 75-80% germinationhad 75-80% germination

container seedlings

J. virginianaJ. virginiana seed seed treatments treatments

seed testing data 2002-1962seed testing data 2002-1962

40

64

5245

74

42

2225

0

10

20

30

40

50

60

70

80

% G

erm

inat

ion

mean germ number

Mean Germination by Pretreatment

none 28 day 91 day 120 day

Juniperus communisJuniperus communis Seed TreatmentsSeed Treatments

• 15 minutes in H2SO4

• Rinse & use baking soda to neutralize acid & rinse again

• Soak in water overnight• Plant in July, germinate in

April-May• 25% TZ yields 20%

germination• 50% TZ yields 30-35%

germination• Seed source – ITALIA• Lawyer Nursery, Montana

Juniperus osteospermaJuniperus osteospermaSeed treatmentsSeed treatments

• 45 days moist warm, 120 days cold moist stratification

• Germination inhibited above 15°C

• Seed stored at 10-12% moisture viable for 9 years at –7 to 5°C

• 12 week aerated water soak at 5°C yielded 50% germination

• Add GA3 to aerated water, germination is 64%

Juniperus monospermaJuniperus monospermaSeed TreatmentsSeed Treatments

• Some seedlots can germinate Some seedlots can germinate without stratification without stratification

• 48 hour running water, 30 48 hour running water, 30 minutes soak in 30% minutes soak in 30% hydrogen peroxide, hydrogen peroxide, germination was 79% over germination was 79% over 47% for untreated seed47% for untreated seed

• 48 hours leaching + 90 day 48 hours leaching + 90 day cold, moist stratification had cold, moist stratification had 88% germination88% germination

• 24 hour hydrogen peroxide 24 hour hydrogen peroxide soak (5%) + 24 hour GAsoak (5%) + 24 hour GA33 soak soak (250ppm) before 30 day cold (250ppm) before 30 day cold stratification had greatest stratification had greatest germination rategermination rate

Critical ElementsCritical Elements

• Germination temperature – secondary Germination temperature – secondary dormancy induced above 15°Cdormancy induced above 15°C

• Seed dehydration in nursery induces Seed dehydration in nursery induces secondary dormancy – winter irrigationsecondary dormancy – winter irrigation

• Warm and cold, moist stratification still Warm and cold, moist stratification still best for breaking dormancy for nurserybest for breaking dormancy for nursery

• Imbibe seed before stratificationImbibe seed before stratification• Germination about 50% of viabilityGermination about 50% of viability• Heavy seed has best viabilityHeavy seed has best viability• Train collectors not to pick immature Train collectors not to pick immature

seedseed

An international network of An international network of resource specialists working resource specialists working with Juniper forests is needed with Juniper forests is needed to create a comprehensive to create a comprehensive program of research and program of research and technology transfer to generate technology transfer to generate and implement new knowledge. and implement new knowledge. (Ciesla 2002; Forests, Trees,and (Ciesla 2002; Forests, Trees,and Livelihoods vol 12Livelihoods vol 12))

ConclusionConclusion