how different pruning intensities and severities mango trees

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XII

INTERNATIONAL

MANGO

SYMPOSIUM

How different pruning intensities and severities affect vegetative growth processes in “Cogshall”

mango trees

S. Persello1, I. Grechi1, F. Boudon2 and F. Normand1

1 CIRAD, UPR HortSys, Réunion Island2 UMR AGAP & INRIA Virtual Plants team, Montpellier

introduction Material and methods results discussion

control the size of the tree(Davenport, 2006)

improve yield and fruit quality(Reddy and Kurian 2011)

improve light

Interception(Menzel and Le Lagadec, 2016)

The interests of pruning

Pruning = an important management of trees:

1

introduction Material and methods results discussion

Aims of the study

Pruning leads to a strong regrowth of

the canopy

Vegetative growth affects flowering

and fruiting(Capelli et al., 2016)

flowering

fruiting

Vegetative growth

Vegetative rest

Characterize the direct effect of pruning on vegetative growth to

better understand the indirect impact on the yield

Characterize the direct effect of pruning on vegetative growth to

better understand the indirect impact on the yield

2

introduction Material and methods results discussion

Aims of the study

Characterize the effects of pruning on

vegetative growth

3

• How pruning stimulates vegetative

growth? More GUs? More burst GUs?

• Where and when vegetative growth

is stimulated?

Characterize the pruning

• At the tree scale: amount of removed

fresh matter

• At the axis scale: depth of pruning

Decouple the 2 factors

To decompose vegetative growth in

elementary processes

To decompose vegetative growth in

elementary processes

introduction Material and methods results discussion

Botanical recalls

Mango tree = succession of growth units

Growth Unit (GU): portion of the axis developed during an uninterrupted period of

growth (Hallé and Martin, 1968)

It exists kindship links between GUs:

- mother GUs produce one or several daughter GUs

Mother GU

Mother GU

Daughter GUs

Daughter GUs

- Growth level: GUs at the same distance from the tip

Growth level

4

introduction Material and methods results discussion

Cultivar: ‘Cogshall’

Characteristics of the trees of the experiment

Location: Reunion island – southern

hemisphere

5

introduction Material and methods results discussion

Cultivar: ‘Cogshall’

Characteristics of the trees of the experiment

Location: Reunion island – southern

hemisphere

pruning

fruiting Vegetative growth Vegetative

rest

flowering

Date of pruning: after the harvest

Age of trees: 13 years

Non-productive trees in the previous cycle

5

introduction Material and methods results discussion

0

0

0

0

0

0

n1: one growth

level removed

n2: two growth

levels removedn3: three growth

levels removed

Axis scale = pruning severity: pruning depth in term of number of

growth levels pruned

Studied factors

GU 1

GU 1

GU 2

GU 1

GU 2

GU 3

6

introduction Material and methods results discussion

Tree scale = pruning intensity: amount of removed fresh matter

Control trees

(unpruned):T0Iight pruning

T1

Moderate pruning

T2

Intense pruning

T3

Removed

fresh

matter

(kg/m3)

0.00±0.00 0.14±0.03 0.30±0.06 0.51±0.06

Studied factors

Corresponds to

growers’ pruning

7

0 n1

0 n2

0 n3

30 n1

30 n2

30 n3

130 n1

130 n2

130 n3

240 n1

240 n2

240 n3

introduction Material and methods results discussion

Data acquisition

4 trees per modality of

pruning intensity

T0

T1

T2

T3

30 unpruned GUs

30 pruned GUs

10 n1

10 n2

10 n3

Stage C

Monitoring (once a week):

Number of

daughter GUsBurst date

8

Effect of pruning Effect of pruning

at distance?

introduction Material and methods results discussion

Number of

daughter GUs

per GU

no

yes

Vegetative

burst

Data analyses

At GU scale:

d1

d2

d3

Mixture of Poisson distribution

(Leisch, 2004)

Binomial

GLM

GLM

Poisson

regression

Threshold probability: 0.01

Response

time

9

Pru

ne

dG

Us

Pru

ne

dG

Us

introduction Material and methods results discussion

Effect of pruning on burst rate

Pruning intensity

(p<<0.001)

10

0.0

0.2

0.4

0.6

0.8

1.0

bb

a

Light

T1

Moderate

T2

Intense

T3

Bu

rst

rate

0.0

0.2

0.4

0.6

0.8

1.0

bba

a

Bu

rst

rate

One level

n1

Two levels

n2Three levels

n3

Pruning severity

(p<<0.001)

0

0

0

un

pru

ne

dG

Us

un

pru

ne

dG

Us

introduction Material and methods results discussion

Effect of pruning on burst rate 11

0.0

0.2

0.4

0.6

0.8

1.0

b

b

a

Pruning intensity

(p<<0.001)

Light

T1

Moderate

T2

Intense

T3

Bu

rst

rate

introduction Material and methods results discussion

Effect of pruning on burst rate

Comparison between pruned and unpruned GUs

(p<<0.001)

pruned unprunedintensity

burs

t rat

e0.

00.

20.

40.

60.

81.

0

a

b

12

introduction Material and methods results discussion

no

yes

Vegetative

burst

summary

Local effect (pruned GUs): distant effect (unpruned GUs):

• Intensity:

T3 > T1,T2

Local (pruned) > distant (unpruned)

• Intensity: T3 > T1,T2

• Severity: n3 > n1

13

Number of

daughter GUs

per GU

Pru

ne

dG

Us

Pru

ne

dG

Us

introduction Material and methods results discussion

Effect of pruning on number of daughter GUs

Pruning intensity

P=0.23

No effect of pruning intensity

Intensity Number of daughter GUs

per GU

T1 3.4

T2 3.1

T3 3.4

Pruning severity

(p<<0.001)

Severity Number of daughter GUs

per GU

n1 2.9 b

n2 2.7 b

n3 4.1 a

14

0

0

0

un

pru

ne

dG

Us

un

pru

ne

dG

Us

introduction Material and methods results discussion

Intensity Number of daughter GUs

per GU

T1 1.6

T2 1.2

T3 1.3

Effect of pruning on number of daughter GUs

Pruning intensity

P=0.02

No effect of pruning intensity

15

introduction Material and methods results discussion

Effect of pruning on number of daughter GUs

pruned unpruned

01

23

4

a

b

Comparison between pruned and unpruned GUs

(p<<0.001)

Ave

rag

e n

um

be

r o

f d

au

gh

ter

GU

s

16

introduction Material and methods results discussion

Number of

daughter GUs

per GU

yes

Vegetative

burstno

Effect of pruning on number of daughter GUs

distant effect (unpruned GUs):Local effect (pruned GUs):

• Intensity: no effect

• Severity: n3 > n2,n1

Pruned GUs > Unpruned GUs

17

Response

time

• Intensity: T3 > T1,T2

• Severity: n3 > n1

• Intensity:

no effect

• Intensity:

T3 > T1,T2

Pru

ne

dG

Us

Pru

ne

dG

Us

introduction Material and methods results discussion

Effect of pruning on vegetative growth timing

Pruning intensity

18

Light pruning

T1

Moderate pruning

T2

Intense pruning

T3

48 days

55 days

22 days

30 days

32 days

Pru

ne

dG

Us

Pru

ne

dG

Us

Effect of pruning on vegetative growth timing

Pruning severity

introduction Material and methods results discussion

19

Light pruning

T1

T1-n1

days since pruning0 10 20 30 40 50 60 700.

000.

100.

20

One growth level

removed: n1 T1-n2

days since pruning0 10 20 30 40 50 60 70

0.00

0.10

0.20

Two growth levels

removed: n2 T1-n3

days since pruning0 10 20 30 40 50 60 700.

000.

100.

20

Three growth

levels removed: n3

de

nsi

ty0

0

0

Pru

ne

dG

Us

Pru

ne

dG

Us

Effect of pruning on vegetative growth timing

T2-n1

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

T2-n2

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

T2-n3

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

introduction Material and methods results discussion

20

Moderate pruning

T2

One growth level

removed: n1

Two growth levels

removed: n2

Three growth levels

removed: n3

Pruning severity0

0

0

Pru

ne

dG

Us

Pru

ne

dG

Us

Effect of pruning on vegetative growth timing

introduction Material and methods results discussion

21

T3-n1

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

T3-n2

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

T3-n3

days since pruning

Den

sity

0 10 20 30 40 50 60 70

0.00

0.05

0.10

0.15

0.20

One growth level

removed: n3

Two growth levels

removed: n2

Three growth levels

removed: n3

Intense pruning

T3

Pruning severity0

0

0

Effect of pruning on vegetative growth timing

un

pru

ne

dG

Us

un

pru

ne

dG

Us

48 days

43 days

37 days

introduction Material and methods results discussion

Pruning intensity

22

Light pruning

T1

Moderate pruning

T2

Intense pruning

T3

Effect of pruning on vegetative growth timing

introduction Material and methods results discussion

Comparison between pruned and unpruned GUs

23

0 20 40 60 80

0.00

0.02

0.04

0.06

0.08

0.10

λ1= 22.5 days

λ2= 47.7 days

prunedunpruned

λ= 47.6 days

0 20 40 60 80

0.00

0.02

0.04

0.06

0.08

0.10

λ1= 29.9 days

λ2= 54.9 days

λ= 42.6 days

0 20 40 60 80

0.00

0.02

0.04

0.06

0.08

0.10

λ= 32.5 days

λ= 36.6 days

de

nsi

ty

Days after pruning

Light pruning

T1

Moderate pruning

T2

intense pruning

T3

Days after pruning

de

nsi

ty

Days after pruning

de

nsi

ty

Pruned GUs

Unpruned GUs

Number of

daughter Gus

per GU

yes

Vegetative

burstno

Effect of pruning on vegetative growth timing

introduction Material and methods results discussion

distant effect (unpruned GUs):Local effect (pruned GUs):

24

Response

time

• Intensity: number/date

of flushes

Severity: number/date

of flushes for T1

• Intensity:

date of flush

advanced

• Intensity: no effect

• Severity: n3 > n2,n1

• Intensity:

no effect

• Intensity:

T3 > T1,T2 • Intensity: T3 > T1,T2

• Severity: n3 > n1

Discussion and perspectives

Pruning stimulates vegetative growth locally and at

distance (Fumey et al., 2011)

Study the impact of vegetative growth on flowering

and yield

positive relationship between yield and leaf

area per tree (Davie and Stassen, 1997)

An important regrowth can delay or prevent

flowering (Menzel and Lagadec, 2016)

25

Synchronization of vegetative growth

perspectives:

no

yes

Vegetative

burst

Response

time

Number of

daughter Gus

per GU

introduction Material and methods results discussion

How pruning stimulates vegetative growthIncrease burst rate (intensity and severity pruning)

increase number of daughter GUs (severity pruning)

Where vegetative growth is stimulated?

When vegetative growth is stimulated?

Discussion and perspectives 26

Model of growth and development of mango tree(Boudon et al., 2016)

Integration of the effect of pruning

Possibility to simulate an unpruned tree during several cycles of production

introduction Material and methods results discussion

• To Integrate all the knowledges

• To make predictions

XII

INTERNATIONAL

MANGO

SYMPOSIUM

Thank you for your attention

Acknowledgments

This work has been partly carried out as part of the Cirad DPP COSAQagronomical research program (activity 2016-2018) funded by a grant fromEuropean Community (FEDER working program), the Regional Council ofRéunion Island and CIRAD and the ECOVERGER project funded by ONEMAwithin the call APR "Résistance et pesticides" managed by the MEDDEFrench ministry.

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