Monday, August 18, 2014

More Winter Vineyard Work - Pruning

After finishing up the Pinot Noir block, we turned our attention to the Tempranillo, Semillon and Cabernet Sauvignon.
All these varieties are trained to a bilateral cordon (two permanent arms) and are spur pruned (see pics below).
Spacing for the former two is 3m x 2m  (rate of 1666 vines/ha) and for the latter 2m x 2m (rate of 2500 vines/ha)
Other chores included net mending, some end post stay replacement and trellis wire tensioning.
Under vine weeds were also sprayed off.
Now all the blocks are 'sealed off ' and we await bud burst which can't be too far way now for the 'early' varieties.
Vine to be pruned with last season's leafless shoots -  now called canes
 Spur with two canes - low (nearest cordon) and high (furthest from cordon)
Step 1: High cane completely removed
Step 2: Low cane reduced to two buds
Step 3: All other unwanted canes removed
Two budded spurs along vine cordon at approx hand span distance apart
Completed spur pruned vine
Pruning finished for the year

So why prune?
Fruit is only produced on new shoots which come from buds formed on the previous season's shoots (canes).
Therefore it's necessary to reduce the number of buds producing new shoots to manage the quantity and quality of fruit ie. by reducing number and size of canes.
Not getting too technical but this relates to the balance between vegetative and fruit growth.
Pruning also maintains the form and the size of the vine. By limiting the number and position of new shoots on a vine it aids canopy management ie. how the shoots are positioned on a trellis with their limited number prevents shading of leaves and bunches allowing good access to sunshine (photosynthesis). It also promotes air movement and aids good spray penetration within the canopy as disease control measures.
However there are many more aspects to pruning and canopy management with large chapters in viticulture books devoted to it as well as stand alone publications on the subject available.

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