SPRING AND SUMMER MANAGEMENT PRACTICES FOR TABLE GRAPES. Andrew Teubes Viticultural Consultant

Transcription

1 SPRING AND SUMMER MANAGEMENT PRACTICES FOR TABLE GRAPES Andrew Teubes Viticultural Consultant

2 In this presentation Importance of shoot thinning Importance of sunlight penetration into the vine canopy Summer shoot management practices Effects of poor canopy management

3 Importance of sunlight penetration Fruitfulness (grape yield potential) is dependent on Sunlight penetration into canopy during spring and early summer Temperature during early spring and summer Reserve status of the vine (health and vigour) Nitrogen supply Nutrient status Cane maturation during late summer and autumn

4 Bud fruitfulness of Thompson Seedless (White Kishmish) canes as a function of bud position Number of clusters per node SUN SHADE Node position on cane

5 Importance of correct pruning Creates optimal spacing of spurs and canes Adequate area for growth of shoots Balance the bud load for the vigour of the plants

6 CORRECT SPACING: SPUR PRUNING cm

7 CORRECT SPACING: CANE PRUNING

8 Shoot thinning Removal of excessive green shoots from the canes/spurs after bud break Canes: Single shoots cm apart Spurs: 2-3 shoots cm apart Shoot length cm long ideal Remove any double shoots Shoot removal/thinning must be done early in the season Saves valuable time Very important for long term fruitfulness

9 SPUR PRUNING Shoot thinning by hand

10 Suckering of excessive shoots to maintain adequate sunlight penetration SPUR PRUNING Shoots removed No shoots removed XX

11 Spacing between spurs result in good sunlight penetration and spacing of clusters cm

12 CANE PRUNING Shoot thinning at cm shoot length Before thinning Ideal spacing is 12 cm Between shoots on the cane After thinning

13 Before thinning CANE PRUNING Shoot thinning at cm shoot length Remove double shoots After thinning

14 Effects of spring suckering on certain measured parameters of Chenin blanc (1977/78 and 1978/79 seasons) (Stellenbosch, South Africa) (2.5 x 1.2 m spacing) Measured parameters Control (no sucker) Sucker all shoots without clusters Sucker to 3 shoots per spur Sucker to 2 shoots per spur Clusters per vine before sucker Clusters removed per vine Shoots per vine before sucker Shoots removed per vine Yield (kg/plant) Yield (gram/shoot) Shoot mass (kg/ha) Harvest tempo (man hours/ha) Pruning tempo (man hours/ha)

15 Sunlight penetration ideal after early season shoot thinning

16 Shoot receiving enough sunlight Poor sunlight exposure resulting in leaf orientation towards light Healthy canopy Canopy too dense

17 Removal of lateral shoots and leaves around clusters Strong lateral shoot development Clusters hanging freely

18 Tipping and topping of shoots Ideal shoot length cm Canopy before tipping Canopy after tipping

19 1 Management of the I-trellis Shoot tipping 40 cm above top wire

20 Use of shade patterns to evaluate density of canopy Too dense Ideal Shade patterns reflect canopy density (30% sun spots ideal)

21 Canopy formation Bunch zone Good spacing of shoots

22 Cluster position on I-trellis

23 Results of poor canopy management of I-trellis Yellow leaves develop due to too dense canopy Shoots falling over because it was not tipped early enough Leaves shaded, no activity

24 Which system is properly managed?

25 Clusters well spaced, not touching each other on spurs Note complete lignification of shoots

26 Well spaced clusters on canes

27 Well spaced clusters on canes on T-trellis Good sunlight penetration

28 Good sunlight penetration on T-trellis Note sunlight penetration

29 Results of poor sunlight into canopy Poor spacing of spurs = No sunlight in canopy Low yield Poor quality

30 Effects of poor pruning and canopy management Unproductive leaves Poor ripening of shoots Poor maturation of canes Small crop Dead canes in winter

31 Too dense canopy cut open too late result in sunburn Clusters very sensitive too direct sunlight

32 Effect of canopy density on crop yield Treatment Canopy density** Radiant energy µε m -2 s -1 Berry mass (g) Bunch mass (g) Yield per vine (kg) Ideal sunlight 3,36 40,7 1,09 125,4 4,62 Dense canopy 7,20 24,7 0,81 104,7 3,47 Very dense canopy 9,58 3,6 0,63 77,2 2,44 ** Canopy density: Number of leaves between cluster and outside of canopy Increase in canopy density and corresponding shade stress: Decrease in radiant energy in bunch zone Decrease in berry mass Decrease in bunch mass Decrease in yield per vine.

33 Effects of canopy density on cluster size Bunch in high density canopy Bunch in medium density canopy Bunch in ideal density canopy

34 Summary of viticultural practices from bud break to harvest Physiological stage Viticultural practice cm shoot length Shoot thinning 10 cm between new shoots on canes cm between shoots on spurs Remove any double shoots Before bloom Removal of lateral shoots in cluster zone Removal of leaves around clusters After fruit set Before berry softening Tipping of longest shoots at 110 cm shoot length Crop control if required (25-30 clusters maximum/vine) Remove all shoots with clusters on inferior shoots Removal of any new leaves around clusters Before harvest Tipping of shoots again at cm shoot length to maintain adequate sunlight

35 Summary Importance of early season shoot thinning Shoot orientation for maximum sunlight interception Removal of lateral shoots and leaves around bunches on T-trellis Removal of lateral shoots and leaves on I- trellis depends on canopy density Top shoots before they become too long