Controlling Cork Oak Decline
The decline of the cork oak has resulted in significant economic losses for cork producers, reaching such extreme levels that disaster is feared for cork oak ecosystems and the risk of extinction lurks on the horizon. To address this problem, Alfredo Cravador, a researcher at the Mediterranean Institute for Agriculture, Environment and Development – MED, is coordinating the project “Using Phlomis purpurea to control Phytophthora cinnamomi”, the main objective of which is to use biological means to control the decline of the cork oak.
As the researcher explains, “Studies carried out in UAlg laboratories concluded that this severe decline could be linked to a disease caused by an oomycete, Phytophthora cinnamomic. This pathogen populates the soil, infecting and destroying thin roots, leading to a water and nutrient deficit . It is one of the most aggressive known oomycetes, infecting thousands of plant species.”
The control approach suggested uses Phlomis purpurea, a plant that grows spontaneously in the Algarve and Alentejo. It is fully resistant to the pathogen and has antagonistic potential, as proven by studies carried out at UAlg. The genetic, chemical and cyto-histological bases of its resistance were studied by the researcher. As Alfredo Cravador explains, “Its roots secrete one or more compounds that are toxic to Phytophthora into the rhizosphere, stunting its ability to multiply in restricted tests. Its large-scale use in cork oak forests facing severe decline would allow for buffer zones to be created, eradicating Phytophthora and preventing it from progressing through the soil.” Alfredo Cravador also argues that, “New cork oak plantations would thus be protected from disease in certain circumscribed areas. If this approach were to be generalised, it would have a huge impact on reducing the risks of deforestation due to soil diseases, contributing to preserving endangered ecosystems and safeguarding crops susceptible to Phytophthora from devastation.”
Other Quercus species, particularly the holm oak, which is also severely endangered in the Iberian Peninsula, are at serious risk if concrete measures and integrated approaches are not put in place. This investigation therefore contributes to Goal 15 of the UN Sustainable Development Goals, “Life on Land”.
Alfredo Cravador has a Bachelor’s Degree in Chemistry, a PhD in Chemistry and is a researcher at the Mediterranean Institute for Agriculture, Environment and Development – MED.
