RAGWORT HAS always been a curse of livestock farmers, with it's green shoots and yellow flower proving toxic to cattle and horses, yet despite proving lethal if consumed either fresh or wilted, it appears to be on the increase going by the number of phone calls reported to The Scottish Farmer.

This common yellow weed contains Pyrrolizidine Alkaloids (PAs) which are highly toxic to a range of animals including horses and cattle. If consumed by such, it can lead to severe liver damage and often death.

Read more - Ragwort warning issued to horse owners

In silage bales PAs can diffuse out of ragwort and affect the entire mass of silage; thus a single plant in a bale of silage can be enough to poison several animals (SAC, 2005).

However, despite the fact this potent plant is commonplace on many types of unimproved grassland, regulations are there to curb increased populations. The Scottish Government has a controls policy to prevent its spread where it presents a high risk of poisoning horses and livestock or spreading to fields used for the production of forage.

Under the Weeds Act 1959, notice can be served to the occupier to take action to prevent the spread of those weeds. Unreasonable failure to comply with such a notice is an offence.

The Weeds Act applies to common ragwort (Senecio jacobaea); spear thistle (Cirsium vulgare); creeping or field thistle (Cirisium arvense) curled dock (Rumex crispus) and broad-leaved dock (Rumex obtusifolius).

SRUC crops specialist, Martin Richards, said: "Ragwort is covered under the Weeds Act of 1959 which means that an order can be placed over the land occupier if it is thought to be of high or medium risk of seeds spreading in wind to land used for livestock and or forage production.

"But, it is only bad in the wrong place and is a host plant for the Cinnabar moth and other insects in wild areas and nature reserves."

High risk is described as an area where ragwort is present and flowering/seeding within 50m of land used for grazing by horses or other animals or land used for feed/forage production, with medium risk being where ragwort is within 50m to 100m of land used for grazing by horses or other animals or land used for feed/forage production.

He added that at this time of year, the best way to prevent ragwort spreading is to pull it up by the roots and remove it – if there not too many plants.

For denser infestations, cutting it is an option, but not the best method of control as ragwort remains poisonous to horses and cattle even when it is dead, although cutting does prevent seeding.

Later in the year, an autumn spray is possible to control those rosettes that would flower and seed the following summer. Livestock must be excluded after spraying, he said.

Responsibility for control of ragwort lies with the occupier of the land on which the weed is growing. This includes land occupied under a seasonal grazing agreement, the terms of which require the land to be maintained in Good Agricultural and Environmental Condition (GEAC).

For those seeking to prevent the spread of ragwort in any particular area it is expected that all adjacent landowners, occupiers and managers will co-operate and, where necessary, take a collective responsibility for ensuring that effective control of the spread of ragwort is achieved. Where it is impossible to obtain co-operation the issue should be referred to the local Scottish Government Rural Payments and Inspections Directorate Area Office.

The most effective way to prevent the spread of this yellow toxic weed is to preclude its establishment through strategic management rather than last-minute control. In managed grasslands, good agricultural management will minimise the chance of ragwort establishing itself. In amenity areas, road verges, railway land and woodland; any activities which cause disturbance to the soil and the loss of ground cover may increase the risk of ragwort becoming established.

Occupiers of all land, including uncultivated land, derelict areas and waste ground, should be vigilant for the presence of ragwort. A notice under the Weeds Act 1959 can be served on landowners or land occupiers requiring them to control infestations of ragwort to prevent them spreading.