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Mycorrhizal Fungi for Improved Soil
Fertility and Plant Health
(or “Management and Utilization of
Arbuscular Mycorrhizal F...
Introduction



Structure
Function

Management of AM fungi
On-farm production and utilization of
inoculum
Field trials
Arbuscular Mycorrhizal [AM] fungi


Arbuscule
(L. “small tree”)



Mycorrhiza
(Gr. “fungus root”)
- exudate

+ exudate
Development of an arbuscule
Kinden and Brown, 1979
Function of mycorrhizas
Green ash (Fraxinus pennsylvanica)
Other benefits
To the plant:



Enhanced water relations
Enhanced pest resistance

To the soil:


Stability of soil agg...
How does the AM fungus benefit?
AM fungi are “obligate symbionts”
They must live in symbiosis with plants to
complete thei...
How can we take advantage of the
AM symbiosis in agriculture?

1. Manage the AM fungi indigenous to the
soil (row crop far...
I. Farm management practices that
influence indigenous AM fungi
Fertilization
 Pesticide application
 Over wintering cov...
1. Over wintering cover crops


Used for:







Erosion control
Nutrient management
Organic matter
Weed management
...
Over wintering crop of hairy vetch increased the
AM fungus inoculum present in the soil
Long fallow disorder
Similar to bare fallows:



Flooded soil syndrome
Stale weed seed bank treatments
2. Crop rotation








Some AM fungi are more
prolific when grown with a
particular host plant
The AM fungi most
pre...
3. Tillage


Tillage interferes with
two functions of the
extraradical mycelium
of AM fungi:

1. As infective
propagules
2. As nutrient absorbing organs of the
symbiosis
Fairchild and Miller, 1990

S h o o t d r y w t (g )

No added P
0.9

Und...
6. Farming system


The Farming Systems Trial

®
Soils from the organic rotations have a
higher AM fungus inoculum potential
… and greater spore populations


Largely due to the
over wintering cover
crops, the organic
farming systems have
live plant cover 70%
of the year vs. 40...
II. Inoculation with AM fungi
Options:
commercially available inocula
produce it yourself

Target farmers:
vegetable produ...
On-farm inoculum production
Materials
compost
vermiculite
grow bags
Transplant:
Bahiagrass (Paspalum notatum) seedlings
pr...
Considerations


Introduce pathogens?





Introduce weeds?





Compost has pathogen suppressive qualities
Bahiagr...
7 gallon “grow bags”
Inoculum of AM fungi


Spores



Infective hyphae



Colonized roots
Production of propagules of AM fungi in 1:4 [v/v]
mixtures of yard clippings compost and
vermiculite. Results of MPN bioas...
Spore production varies with
dilution
Modifications to on-farm inoculum
production system


Propagate indigenous isolates of AM fungi





Add field soil to...
Modifications to on-farm system
Diluents

Field soil
Where to collect the soil- top 2-4 inches

Means of 3 years
100

-3

Conv

P r o p a g u le s c m

80

Legume
Manure

60
4...
Utilization of inoculum in the
greenhouse
Goal: produce a
well-colonized
seedling via
organic practices,
of comparable siz...
R o o t le n g th c o lo n iz e d (% )

Response of colonization to P level for
tomato, pepper, and bahiagrass
70

Tomato ...
How does this happen?


Roots growing in high P exude less of the
hyphal branching signal




Roots release less sugar ...
Organic media experiment
1. Conventional (Premier pro mix +
Hoag (0.31 ppm P) 3X /wk)
Rodale potting mix (20% compost)
2. ...
Results with leek cv. Musselburgh
Conv
Rodale
0N
BM
Fish
Sunshine
0N
BM
Fish

Shoot wt (g) Shoot %P Colon %
0.09 c
0.15 c
...
C o lo n iz a tio n (% r o o t le n g t h )
C o lo n iz e d r o o t le n g t h (c m )

Follow-up experiment
30

Blood Meal...
Tomato cv. BHN 589
Treatment

Shoot Dry Wt
(g)
Nonmycorrhizal
1. Conv
0.68 ± .04

Colon
(%)

Treatment


Shoot Dry Wt
(g)...
Pepper cv. Revolution


Nonmycorrhizal

1. Conv
Rodale Mix
2. 0 N
3. BM
4. Fish



0.39 ± .02
0.25 ± .02
0.79 ± .05
0.56...
Pepper cv. Revolution yield (Rodale)
Nonmycorrhizal
1. Conv

kg/plant
-

Rodale Mix
2. 0 N
3. Blood meal
4. Fish

1.61 ± ....
Pepper cv. Revolution yield (conv)
Nonmycorrhizal
1. Conv

kg/4plants
7.39 ± 1.07

Rodale Mix
2. 0 N
3. Blood meal
4. Fish...
Tomato cv. BHN (Rodale)
Treatment
Nonmycorrhizal
1. Conv Rodale Mix
2. 0 N
3. Blood meal
4. Fish
Sunshine Mix
5. 0 N
6. Bl...
Tomato cv. BHN yield (conv. farm)
Treatment
Nonmycorrhizal
1. Conv
Rodale Mix
2. 0 N
3. Blood meal
4. Fish
Sunshine Mix
5....
Using the inoculum in the field


General
considerations:






Responsiveness of
the plant
Health of the
background
p...
Health of background AM fungus
population
Is this inoculum effective?
Potatoes 2002

Y ie ld (g p e r p la n t)

700
600

Conventional
Compost

500
400
300
200
100
0

Control

MYKE

On-farm

c...
Total yield of potatoes- 2003

Y ie ld (g p e r 3 p la n ts )

1400

Compost
Conventional

1200
1000
800
600
400
200
0

Co...
Potatoes
Yield (kg per 4m row)
Cultivar
Red Norland
Red Gold
Blue
Yukon Gold

Mycorrhizal
6.1
9.5
6.0
4.9

±
±
±
±

0.5
0....
Strawberry (cv. Chandler)
Yield (kg per 10 plant subplot)
Mycorrhizal

Nonmycorrhizal

5.50 ± 0.15

4.71 ± 0.32

Response
...
Tomatoes
Cultivar
Daybreak
Empire
Florida

San Marzano

Yield (kg per 4 plant subplot)
Mycorrhizal
Nonmycorrhizal
24.1 ± 0...
Yield response of bell peppers, Eagle Point Farm, Kutztown PA
Cultivar

2005

2006

2007

2008

2009

2010

2011

Boynton ...
Leeks cv. Lancelot

Shenk’s Berry Farm 2009
Inoculation of sweet potatoes with AM
fungus inoculum produced on-farm


Inoculation method


Inoculum into
planting hol...
Sweet potatoes, cv. Beauregard
YEAR
2009
2010
2012
2013a
2013b

% increase
14.3
9.1
6.5
7.9*
7.7*

*= cv. Covington
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
Southern sawg  mycorrhizal fungi 2014
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Southern sawg mycorrhizal fungi 2014

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Sustainable Agriculture.
Management and Utilization of Arbuscular Mycorrhizal Fungi.
Take advantage of mycorrhizal fungi for improved soil fertility and plant health.

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Transcript of "Southern sawg mycorrhizal fungi 2014"

  1. 1. Mycorrhizal Fungi for Improved Soil Fertility and Plant Health (or “Management and Utilization of Arbuscular Mycorrhizal Fungi”) David Douds USDA-ARS Eastern Regional Research Center david.douds@ars.usda.gov
  2. 2. Introduction   Structure Function Management of AM fungi On-farm production and utilization of inoculum Field trials
  3. 3. Arbuscular Mycorrhizal [AM] fungi  Arbuscule (L. “small tree”)  Mycorrhiza (Gr. “fungus root”)
  4. 4. - exudate + exudate
  5. 5. Development of an arbuscule Kinden and Brown, 1979
  6. 6. Function of mycorrhizas
  7. 7. Green ash (Fraxinus pennsylvanica)
  8. 8. Other benefits To the plant:   Enhanced water relations Enhanced pest resistance To the soil:  Stability of soil aggregates (glomalin)
  9. 9. How does the AM fungus benefit? AM fungi are “obligate symbionts” They must live in symbiosis with plants to complete their life cycles  Why?     Metabolic division of labor among the structures of the fungus Only the fungus within the root can absorb sugars for energy and make lipids necessary for storage and growth Germinating spores can only grow as long as their stored lipids hold out
  10. 10. How can we take advantage of the AM symbiosis in agriculture? 1. Manage the AM fungi indigenous to the soil (row crop farms) 2. Inoculate with effective isolates (horticulture crops, vegetable farms, labor intensive farms)
  11. 11. I. Farm management practices that influence indigenous AM fungi Fertilization  Pesticide application  Over wintering cover crops  Crop rotation  Tillage  Farming System  Cooperative research with The Rodale Institute
  12. 12. 1. Over wintering cover crops  Used for:      Erosion control Nutrient management Organic matter Weed management Fringe benefit:   Build populations of AM fungi Function as a ‘mini’ crop rotation
  13. 13. Over wintering crop of hairy vetch increased the AM fungus inoculum present in the soil
  14. 14. Long fallow disorder
  15. 15. Similar to bare fallows:   Flooded soil syndrome Stale weed seed bank treatments
  16. 16. 2. Crop rotation     Some AM fungi are more prolific when grown with a particular host plant The AM fungi most prevalent after growth of one crop may not be the ones most beneficial to that crop AM fungi may play a role in yield decline characteristic of continuous monoculture Implications for a big switch to continuous corn for ethanol production?
  17. 17. 3. Tillage  Tillage interferes with two functions of the extraradical mycelium of AM fungi: 1. As infective propagules
  18. 18. 2. As nutrient absorbing organs of the symbiosis Fairchild and Miller, 1990 S h o o t d r y w t (g ) No added P 0.9 Undisturbed Disturbed 0.8 0.7 a. Corn grown for 4 wks in inoculated soil 0.6 0.5 b. Harvest shoot only 0.4 0.3 1 2 3 Cycle S h o o t d r y w t (g ) + 160 µgP g-1 Soil 0.9 0.8 c. Disturb soil in half of pots, replant 0.7 0.6 d. Repeat cycle 0.5 0.4 1 2 Cycle 3
  19. 19. 6. Farming system  The Farming Systems Trial ®
  20. 20. Soils from the organic rotations have a higher AM fungus inoculum potential
  21. 21. … and greater spore populations
  22. 22.  Largely due to the over wintering cover crops, the organic farming systems have live plant cover 70% of the year vs. 40% for the conventional farming system.
  23. 23. II. Inoculation with AM fungi Options: commercially available inocula produce it yourself Target farmers: vegetable producers who grow their own seedlings labor intensive farms
  24. 24. On-farm inoculum production Materials compost vermiculite grow bags Transplant: Bahiagrass (Paspalum notatum) seedlings precolonized by AM fungi Weed and water for one growing season (remove flowers in mild climates) Inoculum is ready for use the following spring Details in the web article on the handout
  25. 25. Considerations  Introduce pathogens?    Introduce weeds?    Compost has pathogen suppressive qualities Bahiagrass unlikely to share pathogens with eventual crop host Bahiagrass is frost killed (temperate climates) Some weeds are present in the compost Functional diversity of AM fungi
  26. 26. 7 gallon “grow bags”
  27. 27. Inoculum of AM fungi  Spores  Infective hyphae  Colonized roots
  28. 28. Production of propagules of AM fungi in 1:4 [v/v] mixtures of yard clippings compost and vermiculite. Results of MPN bioassays. Inoculated AM fungus Propagules cm-3 bag (x106) Glomus mosseae Glomus etunicatum Glomus geosporum Glomus claroideum 120 2.4 750 15.0 120 2.4 365 7.3
  29. 29. Spore production varies with dilution
  30. 30. Modifications to on-farm inoculum production system  Propagate indigenous isolates of AM fungi    Add field soil to compost+ vermiculite mix Pre-inoculate bahiagrass with field soil Use of alternate “inert” diluents   Horticultural potting media Perlite
  31. 31. Modifications to on-farm system Diluents Field soil
  32. 32. Where to collect the soil- top 2-4 inches Means of 3 years 100 -3 Conv P r o p a g u le s c m 80 Legume Manure 60 40 20 0 0 10 20 30 40 50 60 70 80 Soil Depth Rodale Farming Systems Trial
  33. 33. Utilization of inoculum in the greenhouse Goal: produce a well-colonized seedling via organic practices, of comparable size to a conv.-grown seedling.  Manipulation of media, N P availability 
  34. 34. R o o t le n g th c o lo n iz e d (% ) Response of colonization to P level for tomato, pepper, and bahiagrass 70 Tomato (Crista) Pepper (Lafayette) Bahiagrass 60 50 40 30 20 10 0 0 10 20 30 40 50 P concentration (ppm) 60 70
  35. 35. How does this happen?  Roots growing in high P exude less of the hyphal branching signal   Roots release less sugar to the fungus already within the root   This leads to less spread of colonization Less carbohydrate supplied to the fungus   This leads to less new colonization This leads to decreased spore production An important factor for the utilization of AM fungi in the greenhouse
  36. 36. Organic media experiment 1. Conventional (Premier pro mix + Hoag (0.31 ppm P) 3X /wk) Rodale potting mix (20% compost) 2. No N addition 3. + Blood Meal (add all at once, 9 g/flat) 4. + Fish (added 3X /wk) Sunshine Mix #1 (SunGro Horticulture) 5. No N addition 6. + Blood Meal (add all at once) 7. + Fish (added 3X /wk)
  37. 37. Results with leek cv. Musselburgh Conv Rodale 0N BM Fish Sunshine 0N BM Fish Shoot wt (g) Shoot %P Colon % 0.09 c 0.15 c 27.7 ab 0.08 c 0.25 a 0.16 abc 0.35 ab 0.40 ab 0.42 a 27.8 ab 3.2 c 16.6 bc 0.12 bc 0.19 ab 0.19 ab 0.36 ab 0.29 b 0.33 ab 34.2 a 5.7 c 16.2 bc
  38. 38. C o lo n iz a tio n (% r o o t le n g t h ) C o lo n iz e d r o o t le n g t h (c m ) Follow-up experiment 30 Blood Meal 3x/wk Blood Meal To A 20 10 0 0 1 2 3 4 36 30 B 24 18 12 6 0 0 1 2 3 4 2 3 4 In fe c tio n U n its 35 30 C 25 20 15 10 5 0 0 1 Weeks Leek cv. Musselburgh in the growth chamber  Single addition of blood meal did not inhibit early colonization, but inhibited subsequent spread of colonization.  Hoag -P
  39. 39. Tomato cv. BHN 589 Treatment Shoot Dry Wt (g) Nonmycorrhizal 1. Conv 0.68 ± .04 Colon (%) Treatment  Shoot Dry Wt (g) Colon (%) 0 Mycorrhizal 1. Conv 0.62 ± .03 15.0 ± 1.2 Rodale Mix 2. 0 N 3. Blood meal 4. Fish 0.52 ± .03 0.92 ± .06 0.87 ± .09 0 0 0 Rodale Mix 2. 0 N 0.27 ± .02 3. BM 1.00 ± .08 4. Fish 0.76 ± .03 6.7 ± 1.3 3.7 ± 0.8 10.3 ± 2.0 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 0.12 ± .01 0.18 ± .05 0.17 ± .02 0 0 0 Sunshine Mix 5. 0 N 0.11 ± .01 6. BM 0.57 ± .03 7. Fish 0.34 ± .05 1.2 ± 0.6 5.3 ± 1.4 8.4 ± 1.4 ANOVA (full model Pr>F) Myc 0.2404 Tmt <0.0001 MXT <0.0001 <0.0001 <0.0001 <0.0001
  40. 40. Pepper cv. Revolution  Nonmycorrhizal 1. Conv Rodale Mix 2. 0 N 3. BM 4. Fish  0.39 ± .02 0.25 ± .02 0.79 ± .05 0.56 ± .04 Sunshine Mix 5. 0 N 0.13 ± .01 6. BM 0.36 ± .04 7. Fish 0.21 ± .02 ANOVA (full model Pr>F) Myc Tmt MXT <0.0001 <0.0001 <0.0001 <0.0001 0.6185 0.6185 Mycorrhizal 0 1. Conv 0.31 ± .024 2.0 ± 0.5 0 0 0 Rodale Mix 2. 0 N 0.22 ± .01 3. BM 0.57 ± .06 4. Fish 0.34 ± .05 1.8 ± 0.8 1.8 ± 0.6 1.5 ± 0.5 Sunshine Mix 5. 0 N 0.09 ± .01 6. BM 0.42 ± .01 7. Fish 0.19 ± .02 2.2 ± 0.7 2.1 ± 0.3 0.8 ± 0.3 0 0 0
  41. 41. Pepper cv. Revolution yield (Rodale) Nonmycorrhizal 1. Conv kg/plant - Rodale Mix 2. 0 N 3. Blood meal 4. Fish 1.61 ± .10 1.73 ± .12 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 1.48 ± .25 1.39 ± .14 1.59 ± .24 1.59 ± .27 ANOVA (full model Pr>F) Myc 0.7162 Tmt 0.2565 MXT 0.7484 Mycorrhizal 1. Conv kg/plant - Rodale Mix 2. 0 N 3. Blood meal 4. Fish 1.49 ± .18 1.74 ± .16 1.74 ± .14 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 1.25 ± .16 1.59 ± .0 1.80 ± .10 *The average yield/plant at local conv. farm= 1.4 - 1.7 kg/plant
  42. 42. Pepper cv. Revolution yield (conv) Nonmycorrhizal 1. Conv kg/4plants 7.39 ± 1.07 Rodale Mix 2. 0 N 3. Blood meal 4. Fish 8.04 ± .76 7.21 ± .79 6.65 ± .91 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 5.61 ± .96 6.64 ± 1.14 6.93 ± 1.12 ANOVA (full model Pr>F) Myc 0.0394 Tmt 0.7928 MXT 0.4314 Mycorrhizal 1. Conv kg/4plants 8.48 ± .79 Rodale Mix 2. 0 N 3. Blood meal 4. Fish 7.00 ± 1.13 7.33 ± .80 8.08 ± .42 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 7.77 ± .46 9.43 ± .73 7.54 ± 1.11
  43. 43. Tomato cv. BHN (Rodale) Treatment Nonmycorrhizal 1. Conv Rodale Mix 2. 0 N 3. Blood meal 4. Fish Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish Mkt Term (kg/2 pl) Treatment Mkt Term (kg/2 pl) Mycorrhizal 1. Conv - 1.9 ±.2 7.6 ±.3 2.8 ±.5 8.9 ±.5 2.9 ±.4 6.9 ±.8 Rodale Mix 2. 0 N 3. Blood meal 4. Fish 2.4 ±.6 2.2 ±.3 3.1 ±.4 6.8 ±.7 7.5 ±.5 8.1 ±.9 1.7 ±.3 7.3 ±.7 2.9 ±.7 6.5 ±.74 2.4 ±.4 7.7 ±.9 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 1.6 ±.5 3.0 ±.3 2.2 ±.4 6.9 ±.5 7.6 ±1.4 7.3 ±1.1 - ANOVA (full model Pr>F) Myc Tmt MXT 0.9374 0.0324 0.8615 0.7956 0.7435 0.5358 Termination after 5 harvests due to late blight.
  44. 44. Tomato cv. BHN yield (conv. farm) Treatment Nonmycorrhizal 1. Conv Rodale Mix 2. 0 N 3. Blood meal 4. Fish Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish Marketable (kg/3 plants) Mycorrhizal 1. Conv 15.5 ± 2.3 15.4 ± 1.7 16.5 ± 1.6 15.8 ± 1.4 14.9 ± 1.6 20.7 ± 2.6 19.5 ± 1.5 ANOVA (full model Pr>F) Myc 0.3353 Tmt 0.2038 MXT 0.4535 19.8 ± 1.2 Rodale Mix 2. 0 N 3. Blood meal 4. Fish 18.2 ± 2.2 16.3 ± 1.3 18.0 ± 0.9 Sunshine Mix 5. 0 N 6. Blood Meal 7. Fish 15.6 ± 1.2 18.0 ± 1.6 18.5 ± 1.9 No early termination
  45. 45. Using the inoculum in the field  General considerations:    Responsiveness of the plant Health of the background population of AM fungi Available Phosphorus level in the soil     Mustards, spinach are not mycorrhizal Generally inversely proportional to the fineness of the roots Hard to measure Critical level >50 ppm, but varies
  46. 46. Health of background AM fungus population
  47. 47. Is this inoculum effective?
  48. 48. Potatoes 2002 Y ie ld (g p e r p la n t) 700 600 Conventional Compost 500 400 300 200 100 0 Control MYKE On-farm cv. Superior
  49. 49. Total yield of potatoes- 2003 Y ie ld (g p e r 3 p la n ts ) 1400 Compost Conventional 1200 1000 800 600 400 200 0 Control MYKE OF-YCC Treatment OF-DMLC
  50. 50. Potatoes Yield (kg per 4m row) Cultivar Red Norland Red Gold Blue Yukon Gold Mycorrhizal 6.1 9.5 6.0 4.9 ± ± ± ± 0.5 0.3 0.2 0.3 Nonmycorrhizal 4.9 8.5 5.4 5.0 ± ± ± ± 0.2 0.2 0.7 0.4 Somerton Tanks Farm, Philadelphia, PA 2005 Response 24% 12% 12% -0.9%
  51. 51. Strawberry (cv. Chandler) Yield (kg per 10 plant subplot) Mycorrhizal Nonmycorrhizal 5.50 ± 0.15 4.71 ± 0.32 Response Shenk’s Berry Farm, Lititz, PA 2005 17%
  52. 52. Tomatoes Cultivar Daybreak Empire Florida San Marzano Yield (kg per 4 plant subplot) Mycorrhizal Nonmycorrhizal 24.1 ± 0.8 30.0 ± 1.1 22.9 ± 1.1 26.5 ± 0.9 30.0 ± 1.7 20.3 ± 0.6 (kg per bed) 156.1 ± 9.2 154.1 ± 11.9 Response -9% 0% 12% 2% Eagle Point Farm, Kutztown, PA and Covered Bridge Farm, Oley, PA 2005
  53. 53. Yield response of bell peppers, Eagle Point Farm, Kutztown PA Cultivar 2005 2006 2007 2008 2009 2010 2011 Boynton Bell 10.7 11.4 -0.05 14.0 9.4 Colossal 3.4 24.7 0.7 8.4 Delirio 15.4 Green Puffin -1.3 King Arthur 10.7 Lafayette 8.1 -6.4 -1.0 3.5 -7.0 -8.0 9.6 Orange Sun 0.2 Queen -1.2 Revolution -3.1 -0.3 8.1 Valencia 3.3 6.5 -1.9 12.0 11.9 Whopper -0.7 -5.1 X3R Red Knight 7.7 X3R Wizard 1.1 -2.1 10.2 6.0 ____________________________________________________________________________ 1 Mycorrhizal Yield Response= 100% x ((Myc-Nonmyc)/Nonmyc)
  54. 54. Leeks cv. Lancelot Shenk’s Berry Farm 2009
  55. 55. Inoculation of sweet potatoes with AM fungus inoculum produced on-farm  Inoculation method  Inoculum into planting hole   2009, 2010 Inoculate potting media and grow in GH for 2 wks  2012, 2013
  56. 56. Sweet potatoes, cv. Beauregard YEAR 2009 2010 2012 2013a 2013b % increase 14.3 9.1 6.5 7.9* 7.7* *= cv. Covington
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