September and October 2009 Douro Insider

The freakish autumn of 2009 has already been discussed enough for us to avoid dwelling on it in too much detail here (see Paul Symington’s Harvest Report 2009). In very simple terms, September was unusually and consistently hot (reaching 39º C in Pinhão) and also remarkably dry. The hot weather (including that which came at the end of August) combined with a lack of water did not pass unnoticed by some of the vines. Whilst we know that our grapevine varieties are extremely drought resistant, part of this capacity comes from the fact that they are able to put down roots to a depth beyond that which is influenced by a single year’s precipitation. On the back of the third consecutive dry year, however, it suddenly became clear that there was a distinct lack of humidity at depth. Certain vines were hit harder than others, but predictably young vines, low-lying vineyards and south-westerly facing hillsides suffered the biggest problems. These vines did the only thing they could, and shed the older, basal leaves to reduce water loss through evapotranspiration. This unfortunately left the bunch zone exposed to the sun, and there were one or two problems with fruit dehydration.

Nevertheless, sugar levels were therefore high, and conditions meant that not a single mouldy grape was seen all harvest. The slightly cooler temperatures up there also ensured that the high altitude vineyards flourished. For once, the best fruit came from above about 350 m, these vineyards really coming into their own in an unusual year and producing grapes of a fantastic quality. If indeed we are to expect a warming of the climate and less consistent rain patterns over the medium term future, we would be imprudent not to learn these lessons from 2009. There was virtually no detectable rain at all during the entire harvest and, with the exception of a freak storm during the first week of October, summer just seemed to go on and on. It was hot, sunny, calm, beautifully clear and at the coast the beaches were still filled with people swimming right up to the end of October. There is not a lot more to be said in general, but it is quite clear that the water tables are in serious need of a refill this winter or the next harvest could be difficult.

Specific climatic information for the last two months reveals some interesting details. Porto woke up to wet streets on the first day of September, with a decent drizzle coming down, and there was thick fog on the Marão too. However, there were no immediate signs of either on the eastern side of the hills where the Demarcated Region begins, even though this little climatic outburst did arrive there later on that day. But by that stage it manifested itself as little more than a strong evening wind. There were a couple of relatively cool and greyish days over the first week, and some more rain in the city, but the vineyards were steadily warming up, and quite dramatically so. By the first weekend of the month it was already very hot, and a number of forest fires broke out between about the 5th and 10th. There was one near Ervedosa, another near Pinhão, and more in the Marão. Ash fell on a number of quintas but there was fortunately no damage to the vineyards.

The second and third weeks were a little cooler in general, with some misty mornings down in Porto, but in the Douro it was clear skies day after day and beautiful vintaging weather. The only complaint might be that it was a little too hot to work comfortably, especially at the end of the month again. The average monthly temperature in Pinhão was 23.0º C, well above the mean of 21.8º, and the overall daily maximum a remarkable 38.9º. There were five consecutive days with temperatures exceeding 35º. The daily minimum was almost always around 15º (although one night still in excess of 20º) but the lowest value recorded was a pretty cool 11.6º. Rainfall was a negligible, coming in at under 2 mm (bear in mind that the average is 40 mm) and remember that Portugal started the month with 96 % of its continental surface area officially suffering from drought. Official figures from the Instituto de Meteorologia make this the driest September in 22 years, a fact apparently confirmed in Pinhão where 1985 had no rainfall whatsoever. By the end of the month that 96 % had risen to 100 %, and the breakdown was as follows: 43 % suffering from severe drought, 3 % extreme drought, 44 % moderate drought and 10 % light drought.

October was a similar month, but really only remarkable for one thing – a truly monstrous storm on the night of the 6th / 7th. The timing could have been a lot worse since the seemingly endless good weather broke, albeit briefly, right as harvesting was coming to an end. Virtually all the vineyards had finished picking by then, but only just. The weather that hit that night was truly furious. The storm was literally strong enough to rip up cobblestones. In a matter of hours over 60 mm of rain tore down, lashed by howling gales. There is no soil in the world capable of absorbing so much water in such a short amount of time but the clays of the Douro, parched and baked by four months of almost complete drought, didn’t stand a chance. There was devastation of both tracks and terraces in practically every vineyard, and widespread flooding. The road into Régua was temporarily closed, and all across the Douro there were teams of firemen clearing mud and debris off the tarmac. A tornado even tore through parts of the Ribatejo. For weeks afterwards diggers worked non-stop in the various quintas to try to put things back in order.

The only positive note was that it demonstrated amazing proof of the protective effects of cover crops against erosion: some of the vertical plantings under grass suffered no detectable damage whatsoever. It also illustrates the importance, in situations where cover crops are being sown rather than left to reseed themselves, of planting the seed as soon as possible after vintage. With the soil still warm the first sign of humidity should encourage early germination, meaning that it is possible to get reasonable coverage of the surface before the majority of the winter rains.

It turns out that this storm had been caused by a cold front running into a depression (consisting of a warm and humid air mass) situated northeast of the Iberian peninsula. The ensuing turmoil predictably brought about a significant drop in temperatures and three or four days of rain. Then, curiously, just as we thought winter was arriving, it went back to being exactly like September again. This was, of course, too warm, too sunny and remarkably dry for this time of the year. The Met Office even officially registered heat waves at a number of weather stations in Portugal, admittedly mostly in the south of the country. Temperatures hitting 30º in mid-October are not normal. This spell was relatively short-lived, however, and it seems that winter did finally arrive for real on the night of the 19th. There was a sudden and dramatic drop in temperatures brought on by a cold front, accompanied by some considerable rain, and the rest of that week was quite wet. There were also sunny breaks during the afternoons, nevertheless.

Pinhão produced a healthy 122 mm of precipitation over the course of the month which, even though it seems a lot, was far less than October in 2003, 2004 and 2006 – all of which yielded over 200 mm. Nevertheless, it is comfortably ahead of the mean value of 76 mm, even if most of it was lost to run-off. What is so surprising is the number of locations that managed to record maximum temperatures in excess of 30º; for instance here it was 30.4º. In spite of October’s rainfall, our usual graphs displayed below confirm that cumulative precipitation is still significantly below where it should be, with a shortfall of nearly 100 mm to make up. The current total is 407 mm but the mean stands at 502 mm for this stage of the year. The temperature graph also confirms what has already been said – the summer was hotter than usual, with the last three months all returning values more than one degree above average. In fact, five out of the last six months have been warmer than average.

As ever, the 31st of October marks the last day of the agricultural year and demands a brief summary of the preceding 12 months. Even looking at the situation from this perspective, we are still finishing the year quite a bit lacking in water. The total of 529 mm is well short of the mean of 675 mm. Moreover, it is the third consecutive drier than average year, and also the fifth out of last six. The last three years have brought a total of 1585 mm of precipitation, when somewhere in the region of 2025 mm would have been expected by the law of averages. The need for a very wet winter has never been clearer.

In terms of temperatures, this year was very fractionally cooler than the mean but the difference is so small that we need two decimal places to show it: 15.86º in 2008 / 09 and 15.94º for the long-term mean. In fact we had six months of above-average temperatures offset by six below-average months. What is more significant, however, is the distribution of the hotter and colder months. It has clearly been a year of extremes, with the winter months quite a bit colder than usual, and (July excepted) the summer was hotter.

With the weather now exhaustively analysed, we can move on to some discussion about what has actually been going on in the vineyards over the last couple of months. As a consequence of the unusual climatic situation in 2009, the period between the workers returning from their summer holidays and actually starting the vintage was shorter than usual. Invariably this time is spent preparing for the harvest, almost entirely revolving around shoot tipping and cleaning the various wineries. There is very little else to do in the vineyards at this stage; we are too close to picking for any treatments to be carried out (which, given the year that it was, were not even remotely called for in any case). Making sure that the pickers and machinery have a clear passage between the rows of vines is therefore by far the most profitable use of time. The only other thing going on before the harvest was some last minute irrigation of the new plantations to try to mitigate the effects of the dry summer.

The start of September also saw the continuation of the maturation studies, carried out by the usual teams of students. As has been mentioned, it was immediately clear that the harvest would have an early start by all accounts. As it happened, not only did we start picking earlier, but due to a drought-reduced crop we also had a relatively small vintage. These two facts combined to make it perhaps the only year in living memory in which many of the winemakers were actually able to spend the feriado of the 5th October at home. Then followed the usual corrections of the batches of wine, and of course a period of intensive adega cleaning, and the pessoal were dismissed for a week or two of rest.

Once the labourers had returned to work again in mid-October, the first thing to be tackled at most of the properties was sorting out the damage caused by the storm. The tracks, terrace banks and old stone walls all needed repairing with some degree of urgency. The worst hit quintas were those in the Rio Torto valley and close to Pinhão. That apart, jobs in the vineyards basically consisted of a bit of a mixed bag of useful things that could be done whilst waiting for the vines to drop their leaves so we could start pruning. There was the usual ploughing in certain locations, and talude cleaning in the case of excessive weed growth. Stone clearing always comes in useful, as well as other minor activities which were also undertaken, such as chopping firewood in preparation for the winter and tending to the vegetable hortas.

It is a good time of the year for cleaning up the olive groves, since obviously vegetation-free ground beneath the trees makes it easier to stretch out the nets that will catch the olives. The warm weather and wet soil also provided perfect conditions for sowing cover crops, and this was done soon after the vintage too so that germination should occur before the real onset of winter. As has already been mentioned, if the soil is too cold at the time of planting the shoots won’t come up until next spring, thereby partially negating the anti-erosion benefits during the fierce winter rains. The only other activity of any consequence occurred in parcelas which are due to be replanted this coming spring. Obviously before we can get the bulldozers in to start preparing the terrain we need to remove the old trellis posts, collect up the wires and rip out the old vines. Only once this has been done, and communicated to the relevant authorities, will permission be given to start the planting procedure.