Keeping our industry informed: Xylella disease update for local plant producers
International travel has never been more popular, and with trade in plants between countries and continents commonplace, the risk of introducing new pests and diseases with potential serious impacts for our local primary production and environment is increasing.
One example is Xylella fastidiosa, a serious bacterial disease, first discovered affecting Olive trees in Italy in 2013, with strains which have the potential to cause serious damage to a wide range of plants and trees were they to be introduced and establish here.
Forest Service’s Plant Health Inspection Branch (PHIB) recently organised an awareness event at CAFRE, Greenmount Campus to highlight this disease to the local horticultural industry, and to provide guidance on statutory obligations and good practice. The meeting was introduced and chaired by Mr John Finlay of PHIB, who emphasised the valuable role that every plant producer/retailer/landscaper can play in minimising the risks from Xylella.
Dr Richard O’Hanlon, Senior Plant Pathologist from the Agri-food and Biosciences Institute (AfBI), outlined the history and life cycle of the disease, as well as reassuring the audience that none of the Xylella fastidiosa strains so far identified have been discovered locally, the nearest interceptions having been in France. Its rate of spread and ability to infect a range of perennial plants is giving serious cause for concern. Richard explained that the symptoms of Xylella infection can often be mistaken for drought or other causes, and that insect vectors such as spittle bugs are critical to its spread.
- Xylella fastidiosa, History and Science - Dr Richard O'Hanlon
Diane Stevenson of DAERA’s Plant Health Policy Branch presented a summary of the policy and actions arising from EU directives and regulations, including recent strengthening of emergency measures against Xylella fastidiosa e.g. all specified Xylella hosts must be accompanied by plant passports, with additional testing requirements applied for specified higher risk hosts.
Sean McIntyre from PHIB Plant Health and Horticulture Inspectorate went on to highlight the potential implications of finding Xylella fastidiosa in Northern Ireland. This could include restrictions of plant movements within 5km of an outbreak site lasting at least 5 years. Early detection is vital if the disease is to be intercepted before establishment.
- Plant Health Inspectorate's response to the risk -Sean McIntyre
Stephen Hamilton, also from the Horticulture Inspectorate, then provided guidance on practical steps that a nursery business could take to reduce the risk of Xylella. He emphasised the importance of informed sourcing of plants, batch management and quarantine measures for newly purchased plants.
- Good practice guidance for producers and sellers - Stephen Hamilton
The event concluded with questions from the audience and a valuable discussion about various implications and possible mitigating actions. John Finlay reiterated the importance of the engagement of industry in protecting against Xylella fastidiosa. The potential UK impact is so great that the Royal Horticultural Society (RHS) has decided to ban the use of imported Xylella-susceptible plants species at their 2018 events (e.g. the Chelsea Flower Show), and a number of horticulture businesses have stopped importing some of the most seriously affected hosts such as Olive, Rosemary and Lavender.
Further information on this disease can be found on the Plant and Tree Health page Xylella fastidiosa.