Farmers want to use banned chemical to control bracken
Sheep-grazing areas will become wastelands if ministers do not urgently allow a banned chemical to be used for treating bracken, farmers have claimed.
Asulam has long been sprayed from helicopters to treat bracken which could otherwise overpower hillsides.
Its use relies on an emergency approval being granted each year by the Scottish government.
There are concerns that Green minister Lorna Slater will not allow it for the first time since it was banned in 2011.
Campaigners are against the use of emergency measures to override bans on dangerous chemicals.
They say there is a risk Asulam can cause cancer and that alternative control measures should be used instead.
Farmers claim those alternatives, like using cutting equipment or allowing cattle to trample the bracken, are often unworkable because of the terrain.
Lorna Maclarty, a farmer at St Fillans in Perthshire, has huge problems with bracken and has used the spraying technique before.
She said: "It's very steep, the ground, and there's no machinery we could get up here to physically chop it.
"In the summer it's a huge problem for us as a hill farm. It's such an invasive plant so we can't actually physically get through it ourselves to gather the sheep off the hill.
"Nothing eats the bracken. It's quite a poisonous plant to most animals so sheep don't touch it and choose not to go into it."
Asulam - sold under the brand name Asulox - is a herbicide which was banned by the EU in 2011 because of concerns it could be an endocrine disruptor which can interfere with the body's hormones.
There is no direct evidence about its link to cancer and further research is ongoing.
Although bracken is not a food product, the worry comes from the spray drifting on to crops or entering watercourses.
Its use has continued since the ban through successive ministers allowing an emergency derogation.
But the environmental charity Pesticide Action Network UK opposes these special measures.
Policy officer Nick Mole said: "All the time that you have these emergency derogations, it stifles innovation, progress and research.
"Reapproving a banned substance because you haven't bothered to find a suitable alternative in the 12 years since it was banned is not a good option."
The ban is also causing concern about the prevalence of ticks which can lead to the debilitating condition Lyme Disease.
Bracken is known to create the perfect conditions for ticks to survive and walkers are advised to be cautious when venturing through it.
Andrew McGillivray, from Air-Agri - a company which carries out aerial spraying - has been lobbying the Scottish government to make a decision but fears that time is running out to perform all the work required.
He said: "You've got public health risks that we know are of concern and we've got loss of biodiversity.
"So, for me, it should be a balanced approach."
He wants the derogations to continue while research is concluded into the potential health risks of Asulam, which could take another 18 months.
The approval of Asulam's use this year is being considered by the Scottish government minister for Green Skills, Circular Economy and Biodiversity, Lorna Slater - a member of the Scottish Greens.
Her party believes use of the chemical is unsustainable and are urging farmers to use alternative control methods.
Scottish Green environment spokesman Mark Ruskell said: "I think it's for land managers to bring in some new innovation around how they can manage bracken but in Ireland, where there's been a ban on the use of this herbicide for the last 10 years, they are continuing to manage bracken and indeed across Europe as well."
The Scottish government said ministers had responded to the Health and Safety Executive, which is responsible for assessing applications and that a decision would be issued once all UK governments had submitted their responses to the HSE's assessment.
A spokeswoman for the Scottish government added: "We are aware of the importance of effective pesticides when used as part of an integrated approach, and our position is guided by regulation and scientific evidence."