“Everything that is alive requires pruning.” Henry Cloud
Pruning is definitely one of the most, if not the most, important tasks in the vineyard. And it’s what we’ve been doing over the past few weeks at Uitsig. Largely responsible for determining the size and quality of the next year’s harvest, the lignified shoots that have lost all their leaves are cut back to a specific length with a specific number of buds, from which new shoots will emerge in the early spring.
This process is a bit more complex than it might at first appear… in fact, some might argue that it’s an art. Prune too early, and you might push the buds to push their shoots too soon before full dormancy is reached. In the areas with lower minimum temperatures, this is a significant threat since frost can devastate the young sensitive shoots causing huge crop losses.
Constantia has higher minimum temperatures, but prune too early, before the vines have experienced enough cold units to put them in dormancy, and the roots that might still be active can initiate a much too early budburst. Chardonnay is especially sensitive to the amount of cold units experienced in winter and if there are not enough, it leads to uneven budburst and uneven ripening. Which is why we leave our Chardonnay shoots until the last moment before pruning.
Of course, if we were to prune too late, then the early varieties will start budding (which requires other management tasks) while we are still pruning the other blocks and then we will fall behind in terms of labour.
To get started, we got the VinPro experts to come and present an annual pruning course upskill our less experienced workers and explain the essential reasons behind this task.
We prune in 3 stages:
First we go through all the blocks and cut the shoots just below the first trellis wires.
Next, we go through all the blocks and select which shoots will be used as next season’s bearers and cut off all the unwanted shoots. This is what we’re doing at the moment.
On Uitsig we have some pretty old vineyards of which some have started showing signs of Leaf Roll virus. Even though we have already started replanting some of these blocks with virus-free material, the main priority is to make sure the younger, healthy blocks are not infected. After pruning, it’s thus essential to protect the vine from possible infection of Leaf Roll and other vineyard diseases. For this, we spray on a Trichoderma fungus that physically grows on the fresh wound and fights off any other pathogens. Pruning shears are also dipped in disinfectant every few vines to eliminate the possibility of spreading Leaf Roll virus with the shears.
Soon, we’ll be entering the last stage of pruning where we cut our selected canes down to a height of about two buds. A last Trichoderma spray job will be given to fresh wounds again. We should be done with all blocks, including the Chardonnay, in the next week or two… the perfect time to put the pruning shears away, rest sore hands, and prepare for the new season ahead…