Good news for anglers and the environment
Himalayan balsam’s infestation of the banks of Welsh rivers could be numbered if a Welsh Government-funded project produces the results expected. As part of the project, scientists from the Centre for Agriculture and Biosciences International (CABI) have just released a biological control agent to combat the spread of this invasive non-native plant.
The biocontrol agent is a pathogenic rust fungus that is host-specific to Himalayan balsam. Scientists from CABI began their search for a suitable agent in 2006 when they travelled to the Indian Himalayas; the native range of Himalayan balsam to find one of the many insects or fungi that attacked the plant. CABI then established which of these could be released in the UK to control the weed while leaving indigenous species unharmed. From this work, CABI successfully isolated a pathogenic rust fungus that does just that. During the course of the research, testing in quarantine laboratories established that the rust fungus causes significant damage to Himalayan balsam without impacting on any native UK species.
Himalayan balsam plants infected with the rust fungus have been planted at four sites in Wales. The progress of the disease will be monitored over the next three years. Early indications are that the rust fungus is successfully spreading to balsam stands within the trial areas and beyond. As with any biocontrol agent, time is the key factor. If successful, it is anticipated that there will be around an 80% reduction in the Himalayan balsam population in Wales in the next five to seven years.
Reported by Medwyn Roberts from Denbigh & Clwyd Angling Club