After months of forecasts promising rain and delivering sunshine, April finally brought some very welcome rain to the Douro Valley. Coupled as it was with periods of overcast and generally cooler than average temperatures throughout the month, the vines were at last encouraged to put forth their shoots.
There were localised showers and even a band of hail on the 2nd of April which stretched from São João de Pesqueira up towards Carrazeda de Ansiães, which are on the south and north sides of the river respectively, around the Valeira Dam. Luckily in these higher altitude areas budburst was barely underway so damage was negligible, despite the heavy fall of hailstones. On the 5th April the mixture of sun and showers resulted in some spectacular rainbows both at Tua and further upriver at Dow’s Quinta da Senhora da Ribeira. The Easter weekend was similarly changeable, but we had some slightly more sustained spells of rainfall towards the end of the month.
The official drought declaration of the Portuguese Institute of Meteorology remained in force however, and on the 30th April 59% of the country was in “severe drought” and 39% in “moderate drought”. The good (ish) news is that no areas this month were listed as suffering “extreme drought”, the worst rating on the scale.
Looking at our graphs for the year to date, April was cooler than average, with the mean temperatures for the month at Pinhão 1.8º cooler than our forty-year average – the coldest April in 12 years. Overall our daily high temperatures across the Douro were 4º cooler than average and our lows were also below average, by not quite 1º.
Precipitation at Pinhão was 56.4 mm versus the 40 year mean 52.6, but this is 5.6 mm less than the mean of 62.0 mm for the last 20 years. Variation across the region was significant, and in an odd reversal of the usual patterns, our quintas in the Douro Superior received around double the rainfall of Malvedos for the month.
In April we finished the last of the new plantation work. This includes planting of americano rootstocks to replace any missing vines and grafting Douro varietals onto the rootstocks planted last year or the year before. Where we have entirely new plantations, we finished the planting where necessary and then began setting in the posts to establish our trellis systems. Though possibly less aesthetically pleasing, we have moved to using metal posts for the majority of our new trellis systems: the traditional blue schist is just too brittle and fragile to stand the occasional knocks from tractors in modern mechanised vineyards and wooden posts generally are heavily impregnated with chemical preservatives, which we would rather not have leaching into the soil of our vineyards. The metal posts combine durability with neutrality in the vineyard environment.
As the vines finally began to send out their shoots, by mid month we got underway with the despampa, the thinning of the shoots to leave just the one strongest on each bud. In tandem with this, we also remove any suckers that are sprouting from the rootstocks – we don’t want the energy of the vine going into these non-productive shoots. This thinning helps to control yields where necessary and limit the density of the canopy, as too thick foliage could hinder the penetration of any anti-fungal treatments. On the other hand, anti-fungal treatments were not a big concern this year – possibly the one and only good thing about the dry winter is that it seems to have pretty well killed off the fungal diseases that linger in the vines, and we have had no mildio and very little oidio, which has been localised and easily controlled.
Finally, with the rain, all kinds of plants came to life, not just the vines, so we began the jobs of weed control and management of cover crops in the vertical plantations, so there was a bit of “lawn mowing” to be done in some quintas.
(Note that the Douro Insider is now a joint effort of Mário Natário, viticulturist for Quinta do Vesuvio and Graham’s Quinta do Vale de Malhadas, and Cynthia Jenson, the Graham’s blogger)