TRELLISING OF GRAPEVINES

INCREASING YIELD AND QUALITY

Andrew Teubes

Viticultural Consultant

In this presentation

• Different types of trellising systems used in the world

• Factors influencing long term grape fruitfulness

• Reasons for trellising or non-trellised cultivation

• Advantages of trellising• Comparison between yields of different

trellis systems

Grape fruitfulness• Fruitfulness=potential of vine to yield fruit

• Two main factors– Sunlight on leaves of basal buds during spring

period, especially during flowering and fruit set

– Temperature during flowering and fruit set

• Any trellis system that will increase the sunlight exposure of the leaves will result in increased fruitfulness

Types of trellis systems

• Bush vines (traditional) – no trellis

• Vertical Shoot Positioning (VSP) – I-trellis

• Semi-horizontal Shoot Positioning– Y-trellis– Double Gable– Trentina (Factory roof)

• Horizontal shoot positioning– T-trellis– Pergola (Spanish Paron, Roof system)

• Unconventional systems

Traditional bush vine

Afghanistan

Shomali

Mazar

Traditional bush vine

Egypt(Nile delta)

Traditional bush vineSpain South Africa

Traditional bush vine

Uzbekistan

Why bush vine and not trellis?

• Reasons for bush vine cultivation– Soil potential medium, therefore do not expect

high vigour in plants (shoot growth stops naturally at 70-80 cm)

– No irrigation or Low availability of irrigation water

• Bush vines naturally yield smaller crops than trellised vineyards

– No capital available for installation of trellising materials (poles, wires, anchors)

Advantages of bush vines

• Low cost– No expensive capital investment required

Disadvantages of bush vines• Low yield potential

– Not suitable for cane pruning (increased bud load)– No support for shoots under high vigour situations

• Disease control not effective– Poor penetration of sprays into canopy

• Weed control very difficult (only by hand)• Grape clusters have lower quality

– Temperature of clusters higher close to soil surface– Physical damage to clusters close to soil– More dust on clusters

• All labour activities problematic– Pruning, shoot removal, leaf removal, harvesting

Grape clusters very close to soil

Sun exposure – sun burn

Dust

Advantages of trellising

• Vine has natural climbing growth habit; trellis provides larger surface area for growth and fruiting

• Increase yield potential– Allows differential pruning techniques (spurs and

canes)• Increase quality of fruit

– Above soil surface, no dust or physical damage– Better micro climate around clusters

• Easy management and mechanization– Weed control– Disease- and pest control– Labour

Management advantages

Easy control of weeds

Comfortable height for workingand picking grapes

Clusters have protection-sun-dust-physical damage

Vertical Shoot Positioning

(I-trellis)

ChileSouth Africa

Semi Horizontal (Y-trellis)

Turkey

Mexico

Semi Horizontal

(Double Gable)

South Africa

Semi Horizontal (Trentina)

SouthAfrica

Horizontal (T-trellis)

South Africa

Saudi Arabia

Pergola (Roof trellis)

South Africa

Chile

Unconventional systems• When are they used?

– When trellis materials are not available or too expensive (poles, wires)

– When climatic factors limit the use of conventional systems

• Continental climates with extreme winter chilling– Vines must be covered with soil in winter to protect from

freezing

• Parts of Northern China, old USSR, Afghanistan, Korea

Egypt Reeds from Nile River is used astrellising material

Afghanistan(Samangan

region)

China

Deep ditchplantation to

resist winter freezeof roots

Close vine spacing to increase vines per hectare

Uzbekistan

Comparison of performance of trellising systems(Chenin blanc/R99, 1980)

Treatment Bush vines

Bush vines

Single

wire

Two

wire

Three

wire

Four

Wire

Five

Wire

1.5 m

Slanting

(5 wire)

Plant spacing

2.6 x

1.3

1.3 x 1.3

2.6 x

1.3

2.6 x

1.3

2.6 x

1.3

2.6 x

1.3

2.6 x

1.3

2.75 x

1.3

Plants/ha 2 959 5 917 2 959 2 959 2 959 2 959 2 959 2 797

Material costs

(Rand/ha)

- - 480 750

5.4 t

900 1430 1720

12.3 t

2400

Yield (ton/ha)

12.50%

22.9 26.1 27.5220%

30.3 32.7 33.6270%

42.6

Yield (kg/plant)

4.2 3.9 8.8 9.3 10.2 11.1 11.4 14.4

Income

(Rand/ha @ R140/t)

1750 3206 3654 3850 4242 4578 4704 5964

Bush vines pruned with short spurs

4.2 kg per vine

Soil surface

Wire

Post70 c

m

Single wire system

.

Soil surface

Shoot growth

Wireposition

Single wire trellis

8.8 kg per vine

Soil surface

Wire 1

70 c

m

Two (2) wire system

Wire 2

30 c

m

.

.Soil surface

Two wire trellis

9.3 kg per vine

Soil surface

Wire 1

70 c

m

Three (3) wire system

Wire 2

30 c

mWire 3

Parallel

.

Soil surface

Three wire trellis

. .Position of parallel wires

10.2 kg per vine

Soil surface

Wire 1

70 c

m

Four (4) wire system

Wire 2

30 c

mWire 3

Parallel

Wire 4

30 c

m

.

Soil surface

Four wire trellis

. ..

.11.1 kg per vine

Soil surface

Wire 1

70 c

m

Five (5) wire system

Wire 2

30 c

mWire 3

Parallel

Wire 4

30 c

m

Wire 5Parallel

.

Soil surface

Five wire trellis

. . .

. . 11.4 kg per vine

Single slanting trellis5 wires

140

cm

Soil surface

Wires

. .. .

.

14.4 kg per vine

Soil surface

Single slanting trellis

Summary

• Trellis systems will always increase yield potential, because– Creates larger area for vine to grow– Allows better sunlight penetration into canopy,

increasing fruitfulness

• Long term high yield will only be sustainable together with– Correct pruning practices– Effective summer shoot management (shoot thinning,

shoot positioning, leaf thinning)

• Regular maintenance of trellis sytem