November 2010 Douro Insider

The month was pleasantly fine and dry to start off with but then, relatively early in, the odd day started to come along that was marked by the predictable return of the capacete (or helmet).  This heavy, mid-level blanket of fog made life fairly miserably at low altitudes, at least during the mornings, but generally burnt off by around midday.  By the start of the second week northern Portugal was hit by a nasty spiralling system that came in off the Atlantic, bringing with it plenty of rain and quite high winds.  It was, in many respects, the start of the winter: temperatures dropped and for the first time since the start of April there were days on which the maximum temperature never reached 15º C.  But the onset of the bad weather was gradual; at least to start with the rainy days were interspersed with cheerfully clear and bright days.  What it did mean, of course, was that there was also a notable decrease in the minimum temperatures, especially when the nights were cloud-free.  But to our good fortune much of the rain that came during the first two-thirds of the month did in fact fall at night which is obviously preferable since it doesn’t interfere with the work in the vineyards. 

There was basically a regular interspersal of rain and sun for most of the month, but during week three in particular there was a lot of precipitation, brought in on the periphery of a low pressure system that flooded parts of Cornwall and the south west of England.  Thereafter the month ran itself out with a sudden and dramatic cooling of daytime temperatures, and some bitterly cold nights too.  This was brought on by a massive weather system that had dramatic repercussions for all of Europe.  The broader picture showed that a large anticyclone had positioned itself over Iceland, where it basically stayed.  In counterpart to this area of high pressure, there was a depression out in the Atlantic over Madeira.  What this effectively did was reverse the usual direction of the prevailing weather, and a cold (continental) mass of air from the north was pushed south-westerly over us and out into the ocean.  It was precisely this system that was responsible for the first of the snowy and icy spells in the UK, where temperatures dropped to -17º and Edinburgh airport was forced to close.

In Portugal we were more or less on the southern edge of this flow of arctic air, but nevertheless its effects here were quite out of the ordinary.  Temperatures plummeted below zero in the Douro and the first frosts of the winter set in.  Then, unbelievably, it snowed so much on the 29th that work in the vineyards had to be abandoned for the rest of the day.  I was unable to find anyone who can remember it ever having snowed in November in the Douro.  Even on the coast, where the temperatures are usually much more amenable, it was still extremely cold but to make things worse it was unpleasantly wet too.

The balance of the month in Pinhão was therefore predictably well below average in terms of temperatures, as we shall soon see, but close to the mean when it came to precipitation.  The actual figure of 73 mm meant that this November was slightly drier than the 87 mm that might have been expected, but obviously this difference is of no significance.  Looking at the precipitation graph below it can be seen that this year’s total cumulative rainfall maintains a lead of around 100 mm over the expected value for this stage of the year: we are currently standing at 687 mm, which is 12 mm more than the long term annual mean and we still have a month in hand.  The fact that this year will end up with above average total rainfall will come as a surprise to nobody, but let us not forget the two summer months that didn’t provide a single drop of water.  Records from other locations across the Douro show considerable spatial variation this month, even by our usual heterogeneous standards, with a factor of two separating the total precipitation of the wettest and the driest quintas.

Temperatures were also very different, with a huge four degrees separating the averages of the hottest and the coldest vineyards.  Frosts were felt everywhere except one or two places right down by the river where the large volume of water kept the air temperature a fraction of a degree above freezing.  Unsurprisingly, given that it even snowed, minimum temperatures were much lower than usual for this time of year, but some really very warm absolute maximums were also felt during the first week, climbing into the mid-20ºs.  It was clearly a month of transition and when the winter hit, it came on hard.  Pinhão’s monthly mean was 10.2º, quite a bit below the reference value of 11.6º.  In fact, November was the second month in a row to deliver a temperature more than a degree below average.

This time of year almost inevitably marks the start of the pruning season, the single activity that takes up the greatest amount of time during the viticultural year.  It can be tedious, so the caseiros will make an effort to intersperse days of pruning with other activities.  It also gives the fingers and wrists a chance to recover from the very strenuous business of spending eight or nine hours with secateurs in hand.  Many of the quintas have mechanical pre-pruners which pass through the vineyards prior to the workers.  By shredding off the greater part of the canes from the wires, the best place to make the pruning cut is easier to see.  It also saves the trouble of struggling to strip the cut canes that are tangled into the trellis by tenacious tendrils.

Mechanical prepruners are not recommended for use in vineyards (usually the older ones) where the traditional blue schist is used for trellis posts as this material, thought extremely hard, is also very brittle.  If you even so much as look at a stone post with the reflection of a tractor in your eyes it might well spontaneously shatter.  In these situations hedge-trimmers have been found to provide a practical alternative as they can be quickly run along the rows just above the fruiting wire.  They also have the advantage that, should there for any reason be an occasional vine in the row that needs to be trained, they can be temporarily withdrawn to leave behind some longer canes.

The last of the leaves hanging on in early November

In certain blocks that have repeatedly proven themselves to produce high quality wines, we may deliberately leave behind hundreds of good canes to be cut at a later date.  These are then sent to a nursery where they will be grafted onto the rootstock of our choice, and a year later we buy them back as ready-grafted rootlings for the new plantations.  This way we can be sure of the quality of the propagation material.

One of the other things that we like to do around this time of year is sowing the cover crops if need be.  Most of the time they reseed themselves but after a few years the balance of the species present may alter and so it is a good idea to plough them into the soil every so often and start afresh.  The earlier this is done the better, since with the soil still relatively warm they should germinate before the onset of the worst of the winter and thus help protect the ground with new growth.  Before sowing, since the soil will have to be ploughed anyway, it may be wise to carry out chemical analyses to see if the vines would benefit from the application of any fertiliser first.

We dedicated a certain amount of time this month to cleaning up the banks of the terraces, removing weeds manually.  It has been a damp year and there are certain rugged plants that even survived the heat and drought of the summer.  Some vineyards were looking a little untidy, and aesthetics is very much a part of viticulture, especially in the Douro.

In the areas that have been chosen for new plantations in 2011 we finished ripping up the old vines and pulling out the trellising so that by the middle of the month the heavy machinery was ready to move in.  Depending on the location, the bulldozers might start with gentle shaping of the terrain to make the slopes more regular, or move straight in to cutting the terraces.  The diggers will then get to work turning over the top layer of soil and digging out or breaking up any rocky outcrops that are lurking below the surface, thereby ensuring good root penetration and the successful establishment of the new vines.

For those interested in picking them, the end of November is usually when the olives ripen so at some quintas it was the start of our second harvest of the year.  There are really plenty of olives on the trees this year (and they are in good condition too) so picking is relatively fast.  On the other hand, the fruit does seem to be clinging on a little harder than usual so plenty of work is required with long sticks to get the olives down.  Given the logistical difficulties of picking in the old vineyards (and transporting the olives out) the demand on labour is considerable.  Economically it might make more sense in some situations not to bother with olive picking, considering the low market prices, so it is by no means as ubiquitous an activity as it was a few years ago.