Although many deny this evidence, climate change is a reality.. We only have to go around the fields of our geography to see how much crops and plant biorhythms have varied. An example is the case of the vineyard and some grape varieties that see a decrease in both the quality and quantity of grapes due to the high temperatures and drought that some territories suffer for a good part of the year.
one of them is Castile-La Mancha, the world’s leading wine region. It is not for nothing that this vast territory, with some 460,000 hectares of vines, holds the title of largest vineyard in the world and is home to around 500 wine companies and cooperatives. An economic sector that, with some 80,000 winegrowers, represents around 5% of the regional GDP.
It is here, it could not be anywhere else, that the agricultural engineer from the University of Castilla-La Mancha (UCLM), Sergio Serrano Parraobtained the grade of excellence very good mention for his doctoral thesis “Evaluation of the behavior of different grape varieties cultivated in drought conditions”. This researcher from Regional Institute for Agri-Food and Forestry Research and Development (IRIAF) He was also the first to read his thesis outside the academic institution, last July, at the headquarters of this agricultural organization dependent on the autonomous government, located in Tomelloso (Ciudad Real).
His work, as he informs ABC, tries to respond to “one of the biggest problems facing viticulture today”, especially in regions with a semi-arid climate, such as Castilla-La Mancha. “In recent decades,” he explains, “vine growing has been very threatened, with varieties that do not give the same results as before, which causes great losses in yield and quality of the grapes.”
In his thesis, Serrano Parra evaluated the behavior of a wide range of varieties over five years (2018-2022) in order to identify those that best resist climatic conditions marked by a severe heat stress and drought such as those already occurring in La Mancha and which will become increasingly common in other wine-growing regionsThe study was carried out specifically on a total of 41 types of vines cultivated in a water deficit regime in the experimental plots of the IRIAF in Tomelloso.
The evaluation of the response to drought, the researcher points out, covered a series of agronomic, physiological and production quality parameters that include, among others, yield, gas exchange or acidity. “Thus, we observed that, for example, varieties such as Macabeo, Garnacha Tinta or Bobal, now widely cultivated – more than 50,000 hectares – seem to respond relatively adequately to drought conditions.. However, others that, mind you, because Tempranillo, which is the most cultivated red grape variety in Spain – with more than 200,000 hectares – and Airén, which is also the most cultivated white grape variety – with 195,000 hectares -, have given us some results “That, in truth, should worry us a lot, because they are not the ones that have the most hope of prospering in these scenarios”, he indicates.
Minority and forgotten varieties
The results obtained show, according to him, “the interest in promoting the planting of certain forgotten varieties, of minority culture or directly non-existent, but capable of responding adequately in conditions of water restriction”. Among them, We distinguish varieties such as Albillo Real, Benedicto, Maquías, Moribel and Tortozona Tinta.. On the other hand, the varieties usually cultivated in Spain, such as Bobal, Garnacha Tinta and Macabeo, showed balanced responses, unlike what was observed in Airén and Tempranillo.
The question now is: what can happen in the not too distant future with certain varieties? This agronomist believes that, for the wine industry to be profitable in the decades to come, a series of agronomic practices will have to be modifiedwhich concern plant material – varieties and rootstocks -, better management of irrigation or modifications to pruning and management systems.
Changes that, according to him, will be difficult to implement because “unfortunately, in many regions, many wineries and cooperatives continue to pay for grapes per kilo, so what interests farmers is producing several kilos of grapes.” However, Sergio Serrano Parra emphasizes that “little by little, this mentality is changing because the current system is not sustainable.”We cannot continue to transport a volume of 22 million hectolitres per year“which means that most of it is then used partly for crisis distillations,” he regrets, referring to what is happening in many regions of La Mancha.
His commitment is thus in favor of “smaller but better quality grape productions”, which would be achieved, according to him, with the alternative represented by these lesser-known, minority and indigenous grape varieties that he includes in his thesis and that adapt better to climate change. In addition, he emphasizes, “they also provide originality and differentiation, characteristics appreciated by the market and the end customer”. We will have to pay attention to this university doctor who prepares the grapes for what is coming.
