RHS calls for help in tackling pear fungus
26 August 2011
Gardeners can help scientists tackle a newly virulent disease of pear trees that appears to be spreading across the country by taking part in a survey for the RHS and TreeWatch.
Pear rust fungus (Gymnosporangium sabinae), which is at its worst from August to October and covers leaves in bright reddish-orange spots, was previously rare in the UK but the RHS Pathology Department is reporting increasing numbers of queries about the disease. It attacks both pear trees and junipers, and needs both species to complete its life cycle.
Now the RHS is asking gardeners to monitor pear trees (Pyrus spp) near their homes for signs of the disease. After marking a tree's location on an online map and recording details such as girth and age, survey participants can use a downloadable field guide to identify if and when it develops signs of infection.
'We are not sure whether this increase in enquiries is due to suitable weather conditions caused by environmental changes, an increased awareness of the fungus, or perhaps it is just part of the natural cycle of this disease,' said Béatrice Henricot, RHS Principal Scientist, Plant Pathology. 'Even though this fungus causes striking bright orange spots, our knowledge of the distribution of it is limited.'
It's hoped by involving gardeners in tracking the spread of the fungus, it will be possible to get a more accurate picture of the current distribution of the disease and find out which pears are worst affected, as well as identifying any cultivars which show some immunity.
More information about pear rust fungus and how to tackle it