After weeks of cool (for the Douro – upper 20’s, low 30’s Celcius) weather, these last few days of June saw a sudden sharp increase, with temperatures Monday, Tuesday and Wednesday around 40ºC. Arlindo, the caseiro at Graham’s Quinta dos Malvedos, commented that it was still 40ºC on the verandah at 5:00 one afternoon when our guests were being served their White Port and Tonics – which must have been outstandingly refreshing and welcome in that heat.
By Thursday temperatures had eased, and Friday was comfortable again with a mixture of sun and high clouds and a bit of late afternoon breeze. The cooler weather is due to hold through Sunday, and then temperatures will climb again, according to forecasts.
We joined Arlindo and viticulturist Alexandre Mariz on Friday, and our first stop was a low lying parcel at Sibio (the property adjacent to Malvedos which we just acquired), where Alexandre was concerned the conditions were ripe for oidium. There was no sign of this fungal disease at all, but we did find a few instances of queima, or sunburn. Whilst the recent 40ºC temperatures would not be very unusual at this time of year normally, coming as it did this year as such a sudden sharp change and accompanied by absolutely cloudless sunny days, some of our grapes have experienced a little sunburn, which turns the grapes into premature raisins.
We are just beginning our desponta, the shoot-trimming and hedging operations in our vineyards. The timing turned out well, as the hitherto untrimmed leaf canopy shaded and protected the vast majority of grapes from the sudden heat and sun this week, and minimised the potential damage from sunburn. It should take us about three weeks to complete the hedging at Malvedos and Tua.
Our regular photo of the Touriga Franca vine at Malvedos brings to mind the phrase “irrational exuberance,” with the vines extending well up above the top wire of the trellis, and reaching out across the path. And the fact that the vines are growing well, and the shoot tips remain green and continuing to extend and put on leaf, is proof that so far our vines are not experiencing hydric stress (see also first photo). Pruning the vines cuts the growing tips and encourages the plant to redirect its energy into maturing the grapes rather than extending vine and putting on more leaf, obviously desirable over the next two months or more leading into harvest.
Over at Quinta do Tua where the vineyards face full south, a young plantation of Sousão showed no signs of sunburn at all, even though the grape clusters have very little foliage cover, in fact the vines were remarkably fresh and healthy. Alexandre said this would be because those plants and grape clusters have been so fully exposed to the sun all season long that they were more accustomed, and therefore more resistant, to the combined heat and sunlight.
In the new plantation at Quinta do Tua, the young vines of Touriga Nacional and Touriga Franca just planted this winter are growing well, and you can see the fresh and lively growing tips. We have watered the plantation once so far this year, and as Alexandre was inspecting the plants, he said we don’t yet need to water again, but this is something he monitors closely every time he visits.
In the photo below of the view across Quinta do Tua, you can clearly see the undulations of the hillside. In the foreground the mature plantation is Touriga Nacional, the next swell of hillside has a young Sousão plantation at the top, and the lower part of that hill and the two folds of hill beyond are all the Touriga Nacional and Touriga Franca plantings made this year. The last fold of hill in the distance which is showing a fresh green is another three year old plantation of Sousão, where the photo above was taken.