WINETECH Technical Yearbook 2020

FIGURE 1. New plantings of wine grapes for Worcester and Breedekloof for the period 2009 - 2018 (hectares).

2009 724,9 2010 866,71 2011 869,71 2012 850,94 2013 793,61 2014 825,87 2015 712,58 2016 611,93 2017 309,48 2018 513,7

TABLE 1. Trellis systems in Worcester and Breedekloof used for the period 2009-2018 (SAWIS).

Hedge

ha Perold

1-strand 2-strand 3-strand 4-strand 5-strand 6-strand 7-strand

831.59 3-strand double lengthened

44.75 12.69

1 165.22 Double lengthened double

489.02 Perold

283.94

308.18 6-strand double lengthened

64.41

Hectare

156.67 6-strand lengthened

3.07 24.6

5.78 7-strand double lengthened

10.49 4-strand lengthened

1 893.72

FIGURE 1. New plantings of wine grapes for Worcester and Breedekloof for the period 2009- 2018 (hectares). 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

Mechanical pruning

282.42 Lengthened double

122.76 760.54

Total

3 249.37 (45%)

5-strand double lengthened

77.96 3 295.44 (46%) Hedge Perold 2009 158,48 499,52 2010 221,01 561,12 2011 265,16 534,01 2012 180,17 485,25 2013 581,65 296,88 2014 448,57 290,69 2015 478,58 190,99 2016 411,75 161,22 2017 217,66 113,96 2018 286,04 145,8 7

Smart Dyson

63.57 5-strand lengthened double

FIGURE 2. A comparison between the use of the hedge and Perold systems for Worcester and Breedekloof for the period 2009 - 2018 (SAWIS).

No trellis system

387.57 5-strand lengthened

Total

Other Total

158.48

700

609.62 (9%) Total hectares 7 154.43 (100%)

600

500

400

THE HEDGE SYSTEM The hedge system consists of a cordon wire with several variations as indicated in table 1 (figure 4). The one-strand system often leads to the turning of the cordon arms on the wire which can cause significant sunburn on the grapes. Wind damage in Worcester and Breedekloof is also a problem as shoots can get blown off the vine due to a lack of support. The advantages of the system are that grapes hang further away from the soil surface, are less prone to rot, and that

sunlight utilisation is very good due to the sprawling canopy. A second wire, between 5-10 cm higher, can limit wind damage and also helps to limit the turning over of the cordons. Over the past 10 years, 3 249.34 hectares (45%) of vineyards have been trellised using this system. A prerequisite for this system is above-average vigour. This means that the soil potential and the choice of cultivar/rootstock play a determining role in the success of any hedge system.

300

Hectare

200

100

0

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

Hedge Perold FIGURE 2. A comparison between the use of the hedge and Perold systems for Worcester and Breedekloof for the period 2009-2018 (SAWIS).

WINETECH TECHNICAL YEARBOOK 2020 138