IT'S a disease that could pose a potential disaster. No it's not covid in humans, or fusarium in grain, or Johnes in cattle – it's a pestilence that is affecting one of our favourite tipples, a gin and tonic.

The gin industry, which is worth £3.2bn to the UK economy, has the potential to be devastated by an invasive plant disease that is posing a threat to one of the basic ingredients that gives gin its distinctive flavour.

A pathogen called phytophthora austrocedri is spreading through juniper trees in Scotland, which produces 70% the UK’s gin ... shock, horror, probe! The warning comes from none other that experts at the Plant Health Centre, including our regular contributor and guru on all things plant disease, Professor Fiona Burnett, from Scotland’s Rural College (SRUC).

In a recent blog for Plant Health Week, Prof Burnett, along with Sarah Green from Forest Research, and Prof Sarah Gurr from the University of Exeter, also highlighted the threat to the Scotch whisky industry from diseases such as ramularia, which can slash barley yields.

The phytophthora austrocedri pathogen entered Britain through the plant trade and may have got into juniper woodlands through well-intentioned planting schemes. It lives in the soil and spreads in both soil and water, infecting juniper roots and killing large numbers of juniper trees especially on wet sites.

Although gin can be produced from spirits derived from a wide choice of grains, or even potatoes, it relies on juniper berries to give it its traditional, distinctive flavour.

Luckily for gin drinkers, researchers in Scotland have found that some junipers are resistant to P austrocedri and it is hoped that natural regeneration will allow juniper populations to recover over time. Science is also helping to identify juniper sites that are less vulnerable to the pathogen and which can be targeted for conservation and protection. Phew!

Members of the public can also take simple steps to help protect the gin industry. These include cleaning soil from boots, bike tyres and dog paws before and after visiting forests, moors and woodlands to prevent disease spreading to new sites.

Prof Burnett said: “Plant Health Week was a chance to flag that everyone can play their part in protecting Scotland’s plant health assets. Whisky is equally at risk to gin through barley diseases which slash crop yields.

"But the principles of best plant health practice such as sourcing seed and plants with care and avoiding moving problems inadvertently in soil apply equally to field crops and the plants in our moorlands, gardens, forests and fields.”

Prof Gurr said: “At a time of heightened awareness of the impact of epidemics on human health, we must also remember that disease has a huge impact upon plant health. Food security and crop protection rely heavily on breeding for disease resistance and upon the widespread spraying of fungicides and insecticides.

“However, despite such disease protection strategies, we still lose around 20 per cent of our crops to disease. We hoped Plant Health Week would raise awareness that disease devastates not only human life but also crops and the very calories we need to sustain us.”

Scotland’s Plant Health Centre was launched in 2018 and is funded by the Scottish Government through its Rural and Environment Science and Analytical Services Division. It brings the plant sectors for forestry, horticulture, environment and agriculture together to co-ordinate plant health knowledge, skills, needs and activities across Scotland.

The centre's directorate is headed up by the James Hutton Institute, and has sector leads from Scotland’s Rural College (agriculture), Royal Botanic Garden Edinburgh (horticulture and environment) and Forest Research (forestry).