Ragwort

Ragwort acts as a cumulative poison, eventually destroying the liver. It is a yellow flowering weed and is poisonous both dead and alive. Ragwort can cause serious liver damage over a period of time. It must be pulled with gloves in the early floret stage and burnt. Be very aware of this weed both on your pasture and in the hay. High risk and a common cause of chronic liver disease.

What is it?

• Ragwort is one of the most frequent causes of plant poisoning of livestock in Britain.
• Ragwort (Senecio jacobaea L.) is one of the injurious weeds specified in the Weeds Act 1959. This Act empowers the respective Agricultural Ministers (in Scotland, The Secretary of State) to serve notice requiring an occupier of land on which ragwort is growing to take action to prevent the weed from spreading.
• Ragwort is normally a biennial (rosette - spring 1st year; flowering - July/August 2nd year).
• Ragwort seeds can be dormant in the soil for up to 20 years.
• Each plant can produce up to 150,000 seeds with a 70% germination rate.

How does ragwort affect livestock?

• Equines and bovines are more susceptible to ragwort poisoning than other livestock.
• Young animals are more susceptible than mature animals. Ragwort poisoning can occur at any time of year.
• Ragwort acts as a cumulative poison, eventually destroying the liver.
• A small intake of ragwort over a long period can be just as damaging as a large intake on a single occasion.
• Little can be done for an animal once the clinical symptoms appear.

Sources of ragwort poisoning

Livestock tend to avoid eating ragwort on good pastures.
• Where there is over-stocking and grass is scarce the weed will thrive and is unavoidably eaten.
• The poisons in ragwort are not destroyed by drying. Dried grass, hay and silage are common sources of ragwort poisoning, it can be undetectable and consumed readily.
• Ragwort becomes much more palatable when cut or wilted, as it loses its bitter taste.

What are the clinical symptoms?

Loss of condition (weight loss, dull coat, depression), poor appetite and constipation, photosensitisation (sunburn) and sometimes jaundice. Terminal Signs: nervous signs develop, restlessness and aimless uncoordinated movement. Animals may appear blind, pressing heads against solid objects, abnormal gait and stance. Most affected animals die after a period of illness varying from a week to several months.

Short term methods / Small Ragwort Infestations

Pulling / digging:

Always wear gloves

• Needs to be done before flowering has completed.
• Ragwort is more easily removed when the plant is immature (seedling or rosette) or after heavy rainfall when the ground is soft.
• Needs to be carried out for at least 2 years as ragwort is a biennial, or if the pasture has a history of ragwort infestation this will have to be carried out annually due to the remaining seeds in the soil.
• It is important to remove as much of the root as possible; ragwort can re-generate like docks from its root fragments. Digging out the entire plant will reduce the possibility of leaving root fragments. Rock salt, bought from any agricultural merchants, poured into the hole after digging helps to kill the remaining roots.
• Tools can be purchased for the job; 'Lazy Dog Tool' or 'Rag Fork'.

• At the early flowering stage reduces seed production.
• Is acceptable in an emergency situation, but generally is not recommended since it encourages more vigorous re-growth.

Prevention is better than cure!

The following represents techniques that can be used singly or in combination to reduce, control or eliminate ragwort. Prevent infestations by good pasture management; the benefits of ragwort control methods are short lived unless the pasture is well managed, as re-infestation will inevitably result. When ragwort is first noticed consider employment of a short-term measure to get rid of existing plants, followed by long-term measures, and improved management to prevent re-infestation. Control needs to be ongoing and combined with good pasture management.

How do you control ragwort in your pasture?

Control of ragwort is the only way to avoid ragwort poisoning. Over and under grazing create open patches where ragwort can readily establish itself. Ragwort will not establish where there is a dense vigorous sward. Such a pasture can be best achieved through controlled grazing and/ or regular fertiliser applications. This encourages root development of grasses and makes a valuable contribution to preventing re-infestation.

• It is important to remove all potential sources of poisoning as quickly as possible.
• To remove the danger to your animals a control strategy must be employed.
• The chosen method of control should be the one least damaging to the environment and human health, whilst still being an effective method of control.

How to recognise ragwort

Seedlings can be found from autumn onwards - the first leaves have a characteristic spade shaped blade, notched at the apex (10-15mm length).

The first true leaf is hairless, 10-12mm in length and oval shaped with a smooth edge. As the plant grows the leaves produced show a gradual increase in the degree of lobbing and waviness typical of the older ragwort plants. Leaves also become hairier as the plant gets older.

Rosettes can be found from early spring onwards - circular cluster of leaves, usually deep green on top and underneath covered in a cottony down, the leaves have a ragged appearance. The rootstock, basal leafstalks and lower parts of the stem may have a purplish/ red colour. (If biennial will over winter as a rosette and during the second year send up a single leafy stem, which will produce numerous flower heads.)

Mature plant - reaches between 1-2m in height, the stems are tough and often tinged purplish/red near the base, but brighter green and branched above the middle. Flowering occurs May to late October. The bright yellow flowers are daisy-like. Most plants die after flowering, creating a gap suitable for immediate colonization by seedlings.

The seeds have a downy appendage making them readily dispersible by the prevailing wind, but can also be dispersed via water or spread by people and livestock.

Weedkillers

A single application of weedkiller will not completely eliminate a ragwort infestation due to overlapping generations of the weed.

The time of year to apply the weedkiller depends on when ragwort was first noticed.

1. Rosette stage first noticed in the spring - first application should be late April or May.
2. Flowering stage - first application should be made as soon as possible before frost damages the foliage. In either case a further application should be made in late April the following calendar year. When to apply - in mild weather when the vegetation is dry and rain is not expected for at least five hours. To avoid wastage and drift, spray on a calm day. All paddocks should be sprayed at the same time to avoid infestation from adjoining paddocks.

How to apply Spot treatment using a knapsack sprayer or weed wiper using a brush, glove or stick with a 'systemic total weedkiller' is effective and least damaging to the environment or use a knapsack sprayer with a 'selective weedkiller'. It should be remembered that 'selective weedkillers' also control other broad-leaved plants, not just the ragwort and therefore leave areas of thin grass sward. Total weedkillers will kill grass.

For advice on the choice of weedkiller and suitable application technique, seek advice from a BASIS trained agronomist by contacting your local agrochemical distributor (see Yellow Pages). Users must follow both product label advice and codes of practice to ensure that the product is used safely and effectively. Please note that two common label statements on the products likely to be used for ragwort control are:-

1. Exclude livestock from the treated area until specified.
2. Palatability of treated ragwort plants is increased therefore removal of all dead plants is essential.

Alternative herbicide

An alternative fully licensed agricultural herbicide - Barrier H produced by Barrier BioTech Ltd. A natural, non-toxic spot spray that can be applied directly to ragwort at all stages of growth and throughout the year and it stands up to cold frosty conditions. Has the advantage over other herbicides that animals only have to be excluded from treated areas for two weeks or until the plant is completely dead. For advice on this herbicide contact Barrier Animal Healthcare, 36-37 Haverscroft Industrial Estate, New Road, Attleborough, Norfolk, NR17 1YE. Telephone 01953 456363, or visit www.ragwort.com

What to do if your land is threatened by ragwort from an external source

Ask the occupier of the land, who is responsible under the Weeds Act 1959, to remove the ragwort. If you are unsuccessful write to:

If ragwort threatens agricultural land or production

• England the nearest Department for Environment, Food & Rural Affairs (DEFRA) Regional Development Service Centre. Helpline Number 08459 33 55 77 (within the UK) available.
• Scotland the nearest Scottish Office Agriculture Environment and Fisheries (SOAEFD) Area Office.
• Wales the nearest Welsh Office Agriculture Department (WOAD).
• Northern Ireland Weed Sciences Applied Plant Sciences Division, DARD. Telephone 02890 255267

If ragwort threatens non-agricultural land

Where such land is under threat from the spread of injurious weeds DEFRA advises that the best course of action is for the complainant to seek a solution with the occupier of the infested land through constructive dialogue and persuasion. Ultimately, however, an occupier of affected land may need to consider civil action through the courts.

Roadside verges

The Highways Agency can be contacted regarding the treatment of verges for ragwort.

Cinnabar moth (Callimorpha jacobaea)

Ragwort is a source of food for the cinnabar moth black and yellow striped caterpillars.