Delayed Pruning of Grapevines

Paul Petrie & Sam Brookes, TWE

Victor Sadras & Martin Moran, SARDI

2

30-Jan

09-Feb

19-Feb

29-Feb

10-Mar

20-Mar

30-Mar

1992 1997 2002 2007 2012

Da

y o

f Y

ea

r

CHR

CAS

Linear (CHR)

Linear (CAS)

Vintage becoming earlier

McLaren Vale Cabernet

Sauvignon

2.1 Days per year

McLaren Vale Chardonnay

1.4 Days per year

3

30-Jan

09-Feb

19-Feb

29-Feb

10-Mar

20-Mar

30-Mar

1992 1997 2002 2007 2012

Da

y o

f Y

ea

r

CHR

CAS

Linear (CHR)

Linear (CAS)

Vintage becoming more compressed

McLaren Vale Cabernet

Sauvignon

2.1 Days per year

McLaren Vale Chardonnay

1.4 Days per year

Peak Demands on

Harvesting and Crushing

Facilities are Increasing

21 Days

9 Days

4

Vintage becoming more compressed

Barossa Shiraz

2006 vs 1998

Day which blocks reached

12Be

Percent regional yield

Maturity (12Be) Date

Pe

rce

nt

of

Re

gio

na

l S

HI Y

ield

0%

20%

40%

60%

80%

100%

14-F

eb

21-F

eb

28-F

eb

7-M

ar

14-M

ar

21-M

ar

28-M

ar

4-Apr

11-A

pr

2006

1998

5

By delaying maturity can we delay harvest?

Delay maturity into a cooler part of the season

Better quality?

Improved harvest logistics

Harvest at optimal time

Better use of facilities

Reduced risk

Extreme events i.e. heat wave

6 6

Winter Spring Summer Autumn

Delayed

Pruning

Can we use delayed pruning in order to delay harvest and move ripening into a

cooler part of the season?

Adaptation strategies in the vineyard Year 1 delayed pruning trial

Standard

Pruning

7

By delaying maturity can we delay harvest?

Five Pruning Dates

26 May (early normal)

4 August (late normal)

5 September (bud burst)

22 September

18 October

No pre-pruning

Unpruned 22 September (Shiraz)

8

By delaying maturity can we delay harvest?

Five Pruning Dates

26 May (early normal)

4 August (late normal)

5 September (bud burst)

22 September

18 October

Pruned 26 May and 22 September (Shiraz)

9

0

5

10

15

20

25

30

35

1/Sep 1/Oct 1/Nov 1/Dec 1/Jan 1/Feb

E-L

Sta

ge

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Tracked Phenology during the growing season

Larger differences earlier

in the season

10

0

5

10

15

20

25

30

35

1/Sep 1/Oct 1/Nov 1/Dec 1/Jan 1/Feb

E-L

Sta

ge

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Tracked Phenology during the growing season

E-L 12 – 5 leaves separated

Inflorescence clear

E-L 17 – 10 leaves separated

flowers separated

11

Tracking fruit colour at veraison (11 January)

Pruned 26 May Pruned 22 Sept Pruned 13 Oct

12 12

Adaptation strategies in the vineyard Year 1 delayed pruning trial

Pruned in May Pruned in September

13

0

20

40

60

80

100

4/Jan 18/Jan 1/Feb 15/Feb 29/Feb

% C

olo

ure

d B

err

ies

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Tracking fruit colour at veraison

Visual scoring

Large spread between

later pruning times.

14

Tracking Maturity

5

7

9

11

13

15

17

19

20/Jan 3/Feb 17/Feb 2/Mar 16/Mar 30/Mar

Ba

um

e

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Large spread between

later pruning times

Earlier pruning times

now closer

Fruit harvested about

14.5 Be for winemaking

15

0

0.5

1

1.5

2

2.5

20/Jan 3/Feb 17/Feb 2/Mar 16/Mar 30/Mar

An

tho

cy

an

ins

(m

g/g

)

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Anthocyanins

Later pruning dates

catch up

13 October is delayed

As per Iland

Wine quality?

16

2

4

6

8

10

12

14

16

20/Jan 3/Feb 17/Feb 2/Mar 16/Mar 30/Mar

Ta

nn

ins

(m

g/g

)

26-May

4-Aug

5-Sep

22-Sep

13-Oct

Tannins

Mouth feel of wine

Harvest decisions

Later pruning dates

catch up

22 Sept & 13 Oct shifted

later

Wine quality ?

17

Yield components

Pruning

Date

Harvest

Date

Yield

(kg/vine)

Bunch

No

Bunch Wt

(g)

Berry Wt

(mg)

Pruning Wt

(g)

26 May 20 Feb 3.9 64.5 51.7 1.1 1137

4 Aug 20 Feb 3.6 67.6 58.0 1.1 1161

5 Sept 28 Feb 2.6 57.3 43.8 1.0 1118

22 Sept 5 March 3.1 78.6 44.1 0.9 887

13 Oct 4 April 1.4 47.3 27.7 0.9 453

Thinned vines yielded approximately 3kg

18

Delaying Maturity 2012-13

Commercial Scale Trials

Shiraz in the Barossa

3 by 10t parcels

Cabernet Sauvignon

in Wrattonbully

3 by 20t parcels

19

Conclusions

Potentially counter some of the critical effects of climate change

Earlier maturity

Compressed vintage

Cost effective

Implement as part of an overall strategy

Not necessarily in the same block every season

20

Acknowledgements

Harry Driscol & Brian Peitch – Database

Greg Wittingham – Phenology

Andrew McLean – Site access

Ethan Nicosia – Berry counting

Craig Galletly & Louise Pridham – Maturity analysis

Brenton Porter & Sara Grafton – Anthocyanin & tannin analysis

Co-authors

Samuel J. Brook – Technical Officer, TWE

Martin A. Moran – Research Officer, SARDI

Victor O. Sadras – Research Scientist, SARDI

21

Questions