Canopy Management in Dry on Vine ‐ ‐(DOV) Raisin Vineyards

Matt FidelibusViticulture and Enology, UC Davis

Presentation outline

• Yield components & reproductive cycle• Environmental factors that affect productivity• Node position and pruning• Trellis & training• Irrigation and nutrition

Yield Components

• Clusters per vine• Berries per cluster• Berry weight• Sugar per berry

Reproductive cycle

• Two-year process• Year 1: Flower clusters are initiated and partially developed on microscopic shoots within buds on green growing shoots.

• Year 2: The pre-formed microscopic shoots emerge from dormant buds, flowers fully develop, and bloom, fruit set, berry growth and maturation occur.

YEAR 1

YEAR 2

- in the developing primary bud

- on the shoot

Clusterinitiation

Rachiselongation,

flowerinitiation

Flower partdifferentiation

Bloom

Pollination&

fertilizationBerry

set

Berry softening

Harvest

YEAR 1

Compound Bud

Lateral (prompt) buds grow out theyear they are formed, resulting inlateral shoots

The dormant bud arises from the most basal node of a lateral shoot. Within the dormant node, anlage develops into shoot, tendril or cluster primordia in the spring.

Anlage Apex Leaf primordia

Earliest indication of a cluster

Compound Bud

By winter, the number of clusters eachshoot will bear in the spring has been set

Fall or winter bud dissections

Sunlight promotes cluster initiation and development and bud survival

• The number and potential size of clusters on preformed shoots is positively correlated with temperature, light, and carbohydrate availability in early summer, when clusters are initiated.

• Shading reduces cluster number and potential size, and promotes bud necrosis (death).

• Pruning: sun canes vs shade canes

IKI stainingcourtesy Jason Smith

NSW Australia

Bu

d f

ruit

fuln

ess

(%)

Time

Bloom

Berry set

Veraison

YEAR 2

Clusters initiated last spring will complete their growth this spring, as the preformed shoots emerge from the dormant nodes and growth to full size.

During this time cluster development can be directly affected by weather, insects, nutrition, and other factors.

Zn application suggested2 weeks prior to bloom

Pollination

The number of berries/cluster and berry size will depend in part on pollination success. Grapes do not require insect pollination, but poor weather and nutrition can substantially affect set.

Node position and pruning

Node position

5 10 15 20

No

de

s w

ith s

hoo

ts (

%)

20

40

60

80

100

15 node canes20 node canes

A Node position

5 10 15 20

No

de

s w

ith s

hoo

ts (

%)

0

20

40

60

80

100

15-node canes20-node canes

B

Node position

5 10 15 20

No

de

s w

ith s

hoo

ts (

%)

0

20

40

60

80

100

15-node canes20-node canes

C Node position

5 10 15 20

No

de

s w

ith s

hoo

ts (

%)

0

20

40

60

80

100

15-node canes20-node canes

D

% Nodes with shoots

Node position

5 10 15 20

Clu

ste

rs p

er

nod

e (

no)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

15-node canes20-node canes

A Node position

5 10 15 20

Clu

ste

rs p

er

nod

e (

no.)

0.0

0.5

1.0

1.5

2.0

2.5

15-node canes20-node canes

B

Node position

5 10 15 20

Clu

ste

rs p

er

nod

e (

no.)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

15-node canes20-node canes

C Node position

5 10 15 20

Clu

ste

rs p

er

nod

e (

%)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

15-node canes20-node canes

D

Number of clusters per node

Node position

5 10 15 20

Clu

ste

r w

eig

ht (

kg)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

15-node canes20-node canes

A Node position

5 10 15 20

Clu

ste

r w

eig

ht (

kg)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

15-node canes20-node canes

B

Node position

5 10 15 20

Clu

ste

r w

eig

ht (

kg)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

15-node canes20-node canes

C Node position

5 10 15 20

Clu

ste

r w

eig

ht (

kg)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

15-node canes20-node canes

D

Cluster weight (kg)

Node position

5 10 15 20

So

lub

le s

olid

s (B

rix)

19

20

21

22

23

24

25

26

27

15-node cane20-node cane

A Node position

5 10 15 20

So

lub

le s

olid

s (B

rix)

18

19

20

21

22

23

24

25

26

15-node canes20-node canes

B

Node position

5 10 15 20

So

lub

le s

olid

s (B

rix)

16

18

20

22

24

26

15-node canesCol 3 vs Col 4

C Node position

5 10 15 20

So

lub

le s

olid

s (B

rix)

18.5

19.0

19.5

20.0

20.5

21.0

21.5

22.0

22.5

15-node canes20-node canes

D

Brix

Average length of 15-node canes

DOVine

Thompson Seedless

Fiesta

Selma Pete

Feet

Open gable trellis

“These vigorous Thompson SeedlessVines are crowned too low—30 to 36 inches below the cross arm.Much of the next year’s fruiting woodWas totally or partially shaded duringFruit bud initiation”. L.P. Christensen, 1979.

Light levels at cordon diminishas distance between trellis top and

cordon increases

Distance between cordon and top of trellis

14 16 18 20 22 24 26 28

Pe

rcent full sun

0

2

4

6

8

10

12

14

16

Light levels at nodes 4 to 6 diminish as distance between

trellis top and cordon increases

Distance from trellis top to cordon (inches)

14 16 18 20 22 24 26 28

Pe

rcent o

f full sun

0

2

4

6

8

10

12

14

16

Light levels at nodes 8 to 10 diminish as distance between

trellis top and cordon increases

Distance from trellis top to cordon (inches)

14 16 18 20 22 24 26 28

Pe

rcent full sun

0

10

20

30

40

50

Conclusions

• Renewal shoots need good light exposure in spring and summer to optimize fruitfulness in the following season.

• Pruning is very important, but trellis design and other canopy management practices can significantly affect light levels in renewal zone

• Nutrition and irrigation can directly and indirectly affect production

• Funding from the California Raisin Marketing Board

• L. Peter Christensen, Mike Moriyama, Steve Vasquez, several private growers

Acknowledgements