In a big corporation, the phrase 'staff thinning' might refer to an exercise-diet programme or a restructuring/redundancy process. We're pleased that at Seresin it means something entirely different.
A little over 2 months ago, after a Wednesday morning staff meeting, we pruned the staff rows of Semillon beside our cellar door. Check out the
previous post to see what the vines looked like at the end of September - very different to now, with flowering in full force.
Shoot-thinning, done by hand, is a process of removing some of the new shoots from a growing vine. There are a number of reasons we shoot-thin; for plant health, for fruit quality and to manage yields, and these reasons are heavily inter-related.
We remove shoots which are growing outside the zone we can manage (eg shoots growing horizontally outwards, or downwards) and we remove shoots which might be 'crowding' in a small space. By having a nicely balanced vine, with shoots growing with even spacing we're aiming to manage yields and provide a framework where grapes can ripen evenly. A well-spaced and well-ventilated canopy also allows air to circulate, reducing disease risk. This is especially important in our organic system, instead of using chemicals to prevent or treat disease.
Having a reasonably open canopy also allows the sun to reach the growing points of each shoot. This is important for next year's crop. Receptors in the plant recognise the sun and respond with a cellular commitment to produce a fruitful shoot next year. If it's too cold or if there is insufficient light, the vine's defense mechanism is to protect and preserve it's energy by growing leaf instead of bunches.
By removing shoots we are also removing potential bunches of grapes. Lower yields are desirable from a quality perspective and also for plant health. We aim for low yields to deliver the style of wine we are aiming for. We also consider what yields are appropriate for the vine and are careful not to put too much stress on a vine by asking it to carry more bunches than we think it can carry and ripen. Again, this is important to our organic practices as we don't artificially 'pump up' our vines with synthetic fertilisers and chemicals.
Our staff thinning activity this morning was fueled by Darren's very accomplished and tasty Sushi and chocolate-noodle treats. Come to think of it, that staff-thining exercise-diet programme might be useful .....