November 2009 Douro Insider

There was a changeable start to the month of November, although all things considered the weather was not unpleasant for this time of the year. To begin with it was basically sunny, but differences in atmospheric pressure meant that there were periods of high winds, and plenty of dark clouds being blown swiftly about the sky. These brought occasional showers but things didn’t turn truly wintery until the weekend in the middle of the month. It rained rather too well, a continuous soaking that unfortunately eventually redid much of the damage from October’s storm that we had just repaired. From then on, temperatures dropped consistently for the rest of November and it didn’t just become colder but gloomier too. The first winter fogs initially materialised mostly at quite a high level but they had a tendency to come down towards dusk. As a result the days often started grey and overcast, or with some of this damp fog in the air, but they occasionally brightened up by late-morning. The nights of the last week finally produced some reasonably cold temperatures for the first time this autumn, but it was not enough to bring down the average noticeably.

The sudden deterioration in the weather seems to have been caused by something known as a ‘warm conveyor’. This is a long-lasting flow (in this case, a very strong one) of relatively warm air (which is therefore able to carry more moisture) that kept blowing up from the sub-tropical Atlantic. It was precisely this front that brought such dramatic flooding to many parts of the UK at around that time, and even in Portugal there were recorded cases of more that 20 mm of precipitation falling over a one hour period. Soon after, the Instituto de Meteorologia announced that the North Atlantic hurricane season (a six month period which runs from the start of June) would technically end on the 30th November. They went on to cover their backs fairly comprehensively by adding there could still be storms in the preceding three months, or indeed during the three months afterwards. Finally the month finished cold and wet, with some unusually early but short-lived snow on the Marão hills over the last weekend.

The month was warmer than average on balance (the fourth consecutive such month, and the seventh this year) and also wetter. The good news is that this meant that the official drought status for certain parts of the country, basically the west coast and the north, was finally lifted. However, 60 % of Portugal is still classified as being in a state of drought, albeit a mild one. Pinhão produced 103 mm of rainfall which was somewhat above the average of 87 mm. Although of little significance at this stage, it does bring our cumulative total a little closer to the average line on the precipitation graph. And it still remains a possibility that December will be able to make up the difference. Let us not forget that we finished last year with a ‘deficit’ of 132 mm, and that the corresponding (negative) value was a huge 295 mm in 2007.

The thermometer in Pinhão registered a monthly mean of 13.2º C, comfortably above the long-term value of 11.6º (see the graph below). Oddly enough, the top temperature, 24.5º, came on the very first day of the month, and the absolute minimum (6.0º) was recorded on the very last day of the month. This pattern demonstrates clearly the steep slide into winter that November brought this time around.

The knock-on effects of a small vintage were still being felt to some degree this month since the workforce’s post-harvest holidays had both started and finished at least a week before normal, back in October. This meant that we had a little more time on our hands than usual and time is a luxury that we cannot afford to waste. As a result, the first week or so was an exact extension of last month’s job list: sowing cover crops, fertilising, olive grove clearing and ripping out any vineyards due to be replanted. The earth-moving machinery for terrain shaping has already moved in at some places to get the surriba (terrain preparation) underway for 2010’s new plantations.

It was then on to the pruning, perhaps a little before we might have liked to start but then, on the other hand, the dry summer had taken its toll on the vines and leaf-fall initially appeared to be at a more advanced stage than would have been expected, especially in the drier, low-lying vineyards. All things being equal, we start pruning with the vinhas velhas or the Tinta Roriz. The latter is always the first casta to lose its leaves, and has the added advantage of producing very brittle canes, making it a good place for the prepruner to get to work.

Speaking of the Roriz, something quite odd happened with it this autumn – the latent buds on the very tips of this year’s primary canes began to burst, and particularly the buds at the ends of the laterals too. Completely bare and apparently dormant vines had suddenly grown little bright green tufts of new leaves at their extremities. Almost certainly this bizarre behaviour must have something to do with a growing season played out under heavy drought conditions which suppressed the vines’ natural tendency for growth. When followed by lots of rain and warm temperatures, it finally made new vegetative development apparently possible. This phenomenon was especially common in the case of the younger vines (normally those not yet fully trained) which tend to have a much longer growth cycle anyway. These mini shoots will of course be of no significance since pruning will remove that part of the plant anyway. As ever, prepruning and pruning are accompanied by cane removal or destruction in situ.

Other major jobs at this point in the calendar include the start of the olive picking season. This has always caused some degree of conflict with the pruning since it can take such a long time, and this year there is clearly a lot of fruit on the trees. Normally we start with those most heavily-laden, since obviously each hour of work there renders more kilos of oil. As the winter goes on, cold weather, rain and especially wind will start to strip some of the olives off the trees, and in the end it may not be worth picking everything if yields per day decline too much.

The last of November’s jobs, but by no means the least, was trying to put back together everything that was damaged by all the rainstorms we have been experiencing. Much of what was originally hit in October was unfortunately damaged again – many of the terraces that had collapsed before and since been repaired still hadn’t had time to dry out properly, and when the rain came again the mud was quick to re-liquify. It can be an extremely frustrating and expensive business, appreciated only by those who hire out diggers and other such machines for a living. The tracks were still vulnerable as well, and many had to be made passable again. Likewise the drainage systems in the vineyards which, if blocked by unmanageable quantities of earth and rocks (as was often the case here), can have an effect that can back up hundreds of metres higher up the hillside. Keeping drainage channels flowing clearly is extremely important. The massive downpours also damaged vineyard walls at a number of properties that of course required rebuilding. So whilst all this rain has been something of a blessing for the water tables, its destructive capacity has also been considerable.