|An infected vine leaf|
Sunday, 2 July 2017
This phytopathogenic bacterium (known as Pierce’s Disease in the US) is deadly to vines as well as olives, almonds, citrus and other fruit trees and has been causing destruction in southern Italy, where its presence was first detected in 2013. It was found in the Balearic Islands in 2016 and now for the first time in mainland Spain in Alicante. The bacterium is spread by insects which feed on the plants’ sap, and once the plant is infected a sort of gel forms which blocks the sap flow. It has been causing extensive damage in California since the 1930s or earlier especially in vines, usually spread by an insect known as the “glassy winged sharpshooter”. There is no cure and all that can be done for the moment is to uproot and destroy plants in a radius of 100 metres of the infected one and monitor a radius of 10 kilometres to try to contain the contagion. While insecticide will also hopefully prevent further infection, there are prohibitions on movement of plants from infected areas and on the planting of possible hosts. If this is the new Phylloxera, we are hopefully better prepared this time. Andalucía has been on the alert since 2014, so let us hope Sherry will not be affected.