An infection which hits orange trees, citrus tristeza virus, has been detected in several farms in the Algarve by the Regional Directorate of Agriculture and Fisheries (DRAPALG).
Orange trees are being destroyed to prevent the spread of the disease.
Celestino Soares from DRAPALG told Lusa news agency: “Dozens of farms have been analysed in order to prevent the selling of affected oranges. This virus blocks the circulation of the sap in the orange trees, preventing it reaching the leaves and the stems and giving a yellow colour to the trees.”
The Algarve produces between 250,000 and 300,000 tonnes of citrus fruits per year.