BASISFe PaOtIuNTreS
Weed focus
Ragwort
Graham Paul offers some practical advice on that most awkward of weeds – Ragwort and offers the opportunity of picking up some BASIS points
Rosette stage found in year 1
Common Ragwort (Senecio jacobaeae)
JANUARY 2012 GI 43 BASIS PONTS
Ragwort belongs to the daisy Horses will avoid ragwort in introduced by Mr John Greenway family and along with the pastures MP for Ryedale. SELF ASSESSMENT Groundsels is classified in the When a horse has been poisoned 2. A direct result of Mr Greenway’s genus Senecio. by ragwort, the symptoms include; bill was the publication of ‘The Use the questions below to Common Ragwort (Senecio yellow mucus membranes, Code of Practice for the Control check your understanding jacobaea), as the name implies, depression, and lack of of Ragwort’ by the Department of this topic. Readers can is the most frequently occurring coordination. Sheep and goats have for Environment, Food and Rural claim BASIS points if the species and is normally a biennial, a much greater tolerance to ragwort Affairs (DEFRA). This code defines questions are answered having a rosette stage in the first and will eat small quantities of the the situations in which there is a correctly! year that overwinters and in the plant with relish. Although they likelihood of ragwort spreading second year grows a hairless, leafy do suffer damage to the liver from to neighbouring land where it Circle the correct answer(s) flowering stem that is divided at the consuming ragwort, it is at a much will present an identifiable risk of top. reduced rate than horses, cattle ingestions by vulnerable animals, 1) Which other species Yellow flowers 15 to 20mm and pigs. There are reports that the and provides guidance on the most belongs to the same genus across, are borne in dense, flat- alkaloids kill parasitic worms in the appropriate control measures. The as Ragwort (Senecio)? topped clusters from June until sheep’s stomach, so in small doses Ragwort Control Act 2003 gives a) Ground-ivy November when the plant dies. they can be beneficial. this Code ‘evidential’ status in b) Ground-elder However, in some instances, when Ragwort poses little risk to the any proceedings taken under the c) Groundsel the plant becomes damaged by health of humans since the bitter Weeds Control Act 1959. Failure d) Ground-pine grazing or cutting, changes in its taste precludes its use as a food. to follow this Code is not an offence physiology occur and it becomes a However, alkaloids can be absorbed but non-compliance may be used Insects feeding on the nectar flowering, may be all that is needed liable. It is not uncommon to see a 2) Which of the grazing short-lived perennial, surviving for in small quantities through the skin as evidence in any legal action. to keep pastures free of the potential ragwort plant totally devastated by animals mentioned have several years. when the plant is handled causing Equally, owners/occupiers should hazard to livestock. Alternatively, the caterpillars and one next to it a much greater tolerance Most wild flower references list an allergic reaction in sensitive be able to establish a defence if they the whole plant can be levered out untouched. to the alkaloid toxins in six species of ragwort found in individuals. Among the alkaloids can demonstrate that they have of the soil using a special tool. Hand Ragwort plants? the UK. The other five are; Hoary found in ragwort is a group known adopted control measures that pulling and levering out the plants Chemical control a) Cattle Ragwort (S. erucifolius), Oxford as the sesquiterpine lactones that comply with this Code’s guidance. are best carried out in moist soils. ‘Barrier H’– is an herbicide based b) Sheep Ragwort (S. squalidus) – introduced can cause the condition ‘compositae Gloves must be worn when pulling on a natural product (citronella c) Horses from southern Italy and naturalised dermatitis’. These are different from and handling ragwort, which can oil) that can be used at all stages d) Pigs in Britain, Marsh Ragwort (S. the pyrrolizidine alkaloids that are “The high visibility marking of be disposed of by drying the plant of growth and is marketed in a aquaticus), Silver Ragwort (S. responsible for the toxic effects to the moth and caterpillars is a material, away from access by ready-to-use spot treatment pack. 3) Apart from Common cineraria) – introduced from the the liver that result from eating the livestock, and then burning. It produces a rapid, severe scorch Ragwort which other Mediterranean and naturalised on foliage. warning for predators to leave Cutting down the plants to on ragwort and certain other weeds injurious weeds are cited coastal cliffs in southern England them alone. Survival is also prevent the seed-heads from and will also temporarily scorch the in the Weed Control Act of and Fen Ragwort (S. paludosus) a Five Injurious Weeds maturing should be regarded as grass but this soon recovers. 1959? More than one may rare perennial growing to 2.0m tall Common Ragwort is one of helped by lack of competition for an emergency treatment to halt the Selective herbicides containing apply in the fens in East Anglia. five injurious weeds cited in the their main source of food” spread of the weed and must be MCPA (e.g. ‘Agritox 50’) will give a) Marsh Dock Rumex palustris Ragwort provides a source of Weed Control Act of 1959. The followed up by some other form of moderate control of the rosette b) Spear Thistle Cirsium vulgare food and nectar for around 200 term injurious weed describes an control. stage of the weed. Products c) Curled Dock Rumex crispus invertebrate species in the UK; of invasive species that is injurious 3. The Natural Environment d) Giant Hogweed Heracleum LEFT, BELOW LEFT and One factor that encourages the containing 2,4-D (e.g. ‘Depitox’) will these some 30 are totally dependent to; crops, natural habitats, and Rural Communities Act 2006 BELOW: proliferation of ragwort in pastures give a moderate level of control at mantegazzianum on the plant as their only food ecosystems, humans and livestock delegates the functions available Cinnabar moth: caterpillars and adult is over-grazing, which results in dose rates applying 1.65kg of the source, which makes ragwort an such as horses and other grazing to the Secretary of State under thinning of the grass sward, leaving active ingredient per hectare (3.3L/ 4) Which Government essential part of our native flora. animals. Indeed, Common Ragwort the Weed Control Act to Natural room for this weed to establish. ha of a 500g/L amine formulation) Agency has specific Ragwort contains many different is the only one of the listed species England, a DEFRA agency. Good turf management practices In some situations a repeat powers, delegated by act of alkaloids that are poisonous to that is toxic; the others are included This delegation of functions coupled with a sensible rotation of application may be required for parliament, to investigate animals. It is a particular problem in the legislation because of their enables Natural England to grazing will help to crowd ragwort complete control with 2,4-D. complaints under the Weed to grazing animals such as horses, damaging effect on crops. They are; investigate complaints where out. Mixtures containing the active Control Act 1959? cattle and pigs, whose tolerance to Spear Thistle (Cirsium vulgare), there is a risk that injurious weeds ingredients MCPA + mecoprop-P a) Environment Agency these alkaloids is particularly low, Creeping or Field Thistle (Cirsium might spread to neighbouring land. Biological Control + dicamba, such as ‘Relay Turf’ b) Home Office causing irreversible cirrhosis of the arvense), Curled Dock (Rumex Natural England gives priority to The Cinnabar moth Tyria or ‘Longbow’ will give reasonably c) Natural England liver when an appreciable quantity crispus) and Broad-Leaved Dock investigating complaints where jacobaeae is an interesting species effective control. d) Forestry Commission of fresh ragwort is consumed. (Rumex obtusifolius) there is a risk of weeds spreading that can give some degree of control Glyphosate formulations Fortunately the plant has a very Under the terms of the Weed to land used for grazing horses of ragwort. Both the adult and can be used as spot treatments 5) Which species of moth bitter taste so the fresh foliage is Control Act of 1959, a land occupier or livestock, land used for forage caterpillar feed on ragwort plants applied with a knapsack sprayer provides a biological control rarely eaten by horses and cattle but can be required by the Secretary of production and other agricultural and are not affected by the toxic but these will also kill the grass for ragwort? it becomes much more palatable State for Environment, Food and activities. alkaloids they absorb through their in the immediate vicinity of the a) Orange swift (Hepialus once the plant dies. Rural Affairs to take steps to prevent digestive tracts. They assimilate target plant. It is possible to use sylvina) Hay and silage contaminated the spread of one or more of the Control Measures the toxins into their bodies as a a weed-wiper applicator to apply b) Cinnabar moth (Tyria with ragwort plants can be fatal to five species. However, the growth The Code of Practice for the defence mechanism against birds the glyphosate without damaging jacobaeae) livestock as the toxic alkaloids in of the plant is not made illegal by Control of Ragwort outlines various and other predators, who would the grass. c) Scarlet Tiger (Callimorpha ragwort are not broken down by the act and there is no statutory suggested methods that can be find them unpalatable. With all herbicide treatments, dominula) drying or by the silage process. obligation for control placed upon summarised under the general livestock must be excluded during d) Brown-tail moth (Euproctis Spraying with herbicides to landowners in general. It is only headings of; cultural, biological and Cinnabar moth treatment and kept out of treated chrysorrhoea) remove ragwort can also present a when the potential spread of the chemical control. The high visibility marking of the areas for at least 4 to 6 weeks until danger to grazing animals if they weed to neighbouring landowners moth and caterpillars is a warning all traces of the weed have rotted Acknowledgement of are released back into the pastures is deemed to be harmful that the Cultural Control for predators to leave them alone. away or have been removed. trademarks: ‘Agritox 50’ and too soon after treatment. In this powers of the legislation are used. Hand pulling is an ideal Survival is also helped by lack of Animals are unable to recognise ‘Depitox’ are trademarks of case it is not the herbicide residue Three other pieces of legislation technique for use in areas such competition for their main source dead or dying plants and in most NuFarm UK Ltd. ‘Relay Turf’ is a that causes harm but the presence are relevant to ragwort: as grazing pastures, if there are of food. However, distribution of the cases the decaying plant tissues trademark of Headland Amenity of dead ragwort plants that the 1. The Ragwort Control Act only a few ragwort plants present. Cinnabar moth caterpillars tends will contain higher levels of sugars ‘Longbow’ is a trademark of animals will no longer avoid. of 2003, a private members bill Regular removal, especially prior to to be patchy, making control unre- making them more palatable. Bayer Environmental Science
44 GI JANUARY 2012 JANUARY 2012 GI 45 BASIS PONTS
Ragwort belongs to the daisy Horses will avoid ragwort in introduced by Mr John Greenway family and along with the pastures MP for Ryedale. SELF ASSESSMENT Groundsels is classified in the When a horse has been poisoned 2. A direct result of Mr Greenway’s genus Senecio. by ragwort, the symptoms include; bill was the publication of ‘The Use the questions below to Common Ragwort (Senecio yellow mucus membranes, Code of Practice for the Control check your understanding jacobaea), as the name implies, depression, and lack of of Ragwort’ by the Department of this topic. Readers can is the most frequently occurring coordination. Sheep and goats have for Environment, Food and Rural claim BASIS points if the species and is normally a biennial, a much greater tolerance to ragwort Affairs (DEFRA). This code defines questions are answered having a rosette stage in the first and will eat small quantities of the the situations in which there is a correctly! year that overwinters and in the plant with relish. Although they likelihood of ragwort spreading second year grows a hairless, leafy do suffer damage to the liver from to neighbouring land where it Circle the correct answer(s) flowering stem that is divided at the consuming ragwort, it is at a much will present an identifiable risk of top. reduced rate than horses, cattle ingestions by vulnerable animals, 1) Which other species Yellow flowers 15 to 20mm and pigs. There are reports that the and provides guidance on the most belongs to the same genus across, are borne in dense, flat- alkaloids kill parasitic worms in the appropriate control measures. The as Ragwort (Senecio)? topped clusters from June until sheep’s stomach, so in small doses Ragwort Control Act 2003 gives a) Ground-ivy November when the plant dies. they can be beneficial. this Code ‘evidential’ status in b) Ground-elder However, in some instances, when Ragwort poses little risk to the any proceedings taken under the c) Groundsel the plant becomes damaged by health of humans since the bitter Weeds Control Act 1959. Failure d) Ground-pine grazing or cutting, changes in its taste precludes its use as a food. to follow this Code is not an offence physiology occur and it becomes a However, alkaloids can be absorbed but non-compliance may be used Insects feeding on the nectar flowering, may be all that is needed liable. It is not uncommon to see a 2) Which of the grazing short-lived perennial, surviving for in small quantities through the skin as evidence in any legal action. to keep pastures free of the potential ragwort plant totally devastated by animals mentioned have several years. when the plant is handled causing Equally, owners/occupiers should hazard to livestock. Alternatively, the caterpillars and one next to it a much greater tolerance Most wild flower references list an allergic reaction in sensitive be able to establish a defence if they the whole plant can be levered out untouched. to the alkaloid toxins in six species of ragwort found in individuals. Among the alkaloids can demonstrate that they have of the soil using a special tool. Hand Ragwort plants? the UK. The other five are; Hoary found in ragwort is a group known adopted control measures that pulling and levering out the plants Chemical control a) Cattle Ragwort (S. erucifolius), Oxford as the sesquiterpine lactones that comply with this Code’s guidance. are best carried out in moist soils. ‘Barrier H’– is an herbicide based b) Sheep Ragwort (S. squalidus) – introduced can cause the condition ‘compositae Gloves must be worn when pulling on a natural product (citronella c) Horses from southern Italy and naturalised dermatitis’. These are different from and handling ragwort, which can oil) that can be used at all stages d) Pigs in Britain, Marsh Ragwort (S. the pyrrolizidine alkaloids that are “The high visibility marking of be disposed of by drying the plant of growth and is marketed in a aquaticus), Silver Ragwort (S. responsible for the toxic effects to the moth and caterpillars is a material, away from access by ready-to-use spot treatment pack. 3) Apart from Common cineraria) – introduced from the the liver that result from eating the livestock, and then burning. It produces a rapid, severe scorch Ragwort which other Mediterranean and naturalised on foliage. warning for predators to leave Cutting down the plants to on ragwort and certain other weeds injurious weeds are cited coastal cliffs in southern England them alone. Survival is also prevent the seed-heads from and will also temporarily scorch the in the Weed Control Act of and Fen Ragwort (S. paludosus) a Five Injurious Weeds maturing should be regarded as grass but this soon recovers. 1959? More than one may rare perennial growing to 2.0m tall Common Ragwort is one of helped by lack of competition for an emergency treatment to halt the Selective herbicides containing apply in the fens in East Anglia. five injurious weeds cited in the their main source of food” spread of the weed and must be MCPA (e.g. ‘Agritox 50’) will give a) Marsh Dock Rumex palustris Ragwort provides a source of Weed Control Act of 1959. The followed up by some other form of moderate control of the rosette b) Spear Thistle Cirsium vulgare food and nectar for around 200 term injurious weed describes an control. stage of the weed. Products c) Curled Dock Rumex crispus invertebrate species in the UK; of invasive species that is injurious 3. The Natural Environment d) Giant Hogweed Heracleum LEFT, BELOW LEFT and One factor that encourages the containing 2,4-D (e.g. ‘Depitox’) will these some 30 are totally dependent to; crops, natural habitats, and Rural Communities Act 2006 BELOW: proliferation of ragwort in pastures give a moderate level of control at mantegazzianum on the plant as their only food ecosystems, humans and livestock delegates the functions available Cinnabar moth: caterpillars and adult is over-grazing, which results in dose rates applying 1.65kg of the source, which makes ragwort an such as horses and other grazing to the Secretary of State under thinning of the grass sward, leaving active ingredient per hectare (3.3L/ 4) Which Government essential part of our native flora. animals. Indeed, Common Ragwort the Weed Control Act to Natural room for this weed to establish. ha of a 500g/L amine formulation) Agency has specific Ragwort contains many different is the only one of the listed species England, a DEFRA agency. Good turf management practices In some situations a repeat powers, delegated by act of alkaloids that are poisonous to that is toxic; the others are included This delegation of functions coupled with a sensible rotation of application may be required for parliament, to investigate animals. It is a particular problem in the legislation because of their enables Natural England to grazing will help to crowd ragwort complete control with 2,4-D. complaints under the Weed to grazing animals such as horses, damaging effect on crops. They are; investigate complaints where out. Mixtures containing the active Control Act 1959? cattle and pigs, whose tolerance to Spear Thistle (Cirsium vulgare), there is a risk that injurious weeds ingredients MCPA + mecoprop-P a) Environment Agency these alkaloids is particularly low, Creeping or Field Thistle (Cirsium might spread to neighbouring land. Biological Control + dicamba, such as ‘Relay Turf’ b) Home Office causing irreversible cirrhosis of the arvense), Curled Dock (Rumex Natural England gives priority to The Cinnabar moth Tyria or ‘Longbow’ will give reasonably c) Natural England liver when an appreciable quantity crispus) and Broad-Leaved Dock investigating complaints where jacobaeae is an interesting species effective control. d) Forestry Commission of fresh ragwort is consumed. (Rumex obtusifolius) there is a risk of weeds spreading that can give some degree of control Glyphosate formulations Fortunately the plant has a very Under the terms of the Weed to land used for grazing horses of ragwort. Both the adult and can be used as spot treatments 5) Which species of moth bitter taste so the fresh foliage is Control Act of 1959, a land occupier or livestock, land used for forage caterpillar feed on ragwort plants applied with a knapsack sprayer provides a biological control rarely eaten by horses and cattle but can be required by the Secretary of production and other agricultural and are not affected by the toxic but these will also kill the grass for ragwort? it becomes much more palatable State for Environment, Food and activities. alkaloids they absorb through their in the immediate vicinity of the a) Orange swift (Hepialus once the plant dies. Rural Affairs to take steps to prevent digestive tracts. They assimilate target plant. It is possible to use sylvina) Hay and silage contaminated the spread of one or more of the Control Measures the toxins into their bodies as a a weed-wiper applicator to apply b) Cinnabar moth (Tyria with ragwort plants can be fatal to five species. However, the growth The Code of Practice for the defence mechanism against birds the glyphosate without damaging jacobaeae) livestock as the toxic alkaloids in of the plant is not made illegal by Control of Ragwort outlines various and other predators, who would the grass. c) Scarlet Tiger (Callimorpha ragwort are not broken down by the act and there is no statutory suggested methods that can be find them unpalatable. With all herbicide treatments, dominula) drying or by the silage process. obligation for control placed upon summarised under the general livestock must be excluded during d) Brown-tail moth (Euproctis Spraying with herbicides to landowners in general. It is only headings of; cultural, biological and Cinnabar moth treatment and kept out of treated chrysorrhoea) remove ragwort can also present a when the potential spread of the chemical control. The high visibility marking of the areas for at least 4 to 6 weeks until danger to grazing animals if they weed to neighbouring landowners moth and caterpillars is a warning all traces of the weed have rotted Acknowledgement of are released back into the pastures is deemed to be harmful that the Cultural Control for predators to leave them alone. away or have been removed. trademarks: ‘Agritox 50’ and too soon after treatment. In this powers of the legislation are used. Hand pulling is an ideal Survival is also helped by lack of Animals are unable to recognise ‘Depitox’ are trademarks of case it is not the herbicide residue Three other pieces of legislation technique for use in areas such competition for their main source dead or dying plants and in most NuFarm UK Ltd. ‘Relay Turf’ is a that causes harm but the presence are relevant to ragwort: as grazing pastures, if there are of food. However, distribution of the cases the decaying plant tissues trademark of Headland Amenity of dead ragwort plants that the 1. The Ragwort Control Act only a few ragwort plants present. Cinnabar moth caterpillars tends will contain higher levels of sugars ‘Longbow’ is a trademark of animals will no longer avoid. of 2003, a private members bill Regular removal, especially prior to to be patchy, making control unre- making them more palatable. Bayer Environmental Science
44 GI JANUARY 2012 JANUARY 2012 GI 45