The Control of Ragwort
This plant appears to have alternating seasons of rampant or less rampant growth, and it is currently spreading in the UK (2004). Most stockmen understand that ragwort is very bad or fatal for animals when eaten dried, but do not realise that it is also poisonous when nibbled as a rosette in pasture. It is dangerous in both cases, and never good for the animal concerned. Why ? The toxins in ragwort (Pyrrolozide alkaloids) are cumulative in all animals (and humans). They gradually destroy the liver, so that a small dose towards the middle of a life, can turn out to be the fatal one. A horse only needs 1kg.of this plant to kill it, and contrary to commonly quoted opinion, sheep are also affected by nibbling the rosettes (although they are mostly slaughtered before it kills them).
Rosettes & mature plants need to be removed from pasture, after pulling,cutting, foraging, or spraying. Lazy Dog gangs remove the complete plants from the ground, before tipping them into trailers, ready for burning, burying, or composting. All these operations must be done away from watercourses or animals, and are part of the job.
The application of RIP
1. Using a new shortened version of the Lazy Dog, our gangs aim to remove the plants as rosettes, during the Autumn & Spring. Summer clearance work is considered to be a ‘follow-up’ to this initial effort, which is carried out when the ground is moist, the weather cool, and the burden of other jobs, less pressing.
2. Rosette clearance requires the workforce to make full use of a L-D tool, by getting out of the habit of bending. A collecting bag is carried on one shoulder, and the uprooted plants are either tipped in piles for later collection, or put directly into a smaller trailer.
3. We mostly use the small fork (N07), because plants stick to it while we lift them to waist height.The ‘sheeps foot nose'(N01b), can also be useful where occasional rosettes appears among a majority of docks & thistles (e.g. in field margins in countryside stewardship). N01b is also useful in dry conditions, encountered during the ‘follow-up’ in Summer. A specialist zigzag rake (that we make), can be useful for raking out massed seedling rosettes in winter.
4. After grubbing out a plant, we try to ‘heal in’ the larger divots, to shield any lurking seed-bank from light. Trials in Yorkshire suggest that this is much less of a problem than is often suggested, especially when stock are removed.
5. We wear gloves at all times, because it’s known that the poisonous alkaloids enter the bloodstream via the skin, especially in hot weather (see Dr Derek Knottenbelt, Liverpool Veterinary Research).
Some management suggestions
1. Tightly stocked winter grazing (especially by heavy animals) is asking for trouble on soils that are known to contain a ragwort seed-bank. There is no point in expensively clearing a site, and then allowing heavy or uncontrolled grazing. After clearing any badly infested site (which has previously been paddled or overgrazed), management must ensure that the turf is allowed to thicken up & repair. In an ideal world all grazing should be replaced by mechanical topping for two growing seasons.
2. If grazing is continued, it should be kept very light. Cull sheep could perhaps be used to fulfill this role, and areas where grazing is habitually concentrated, should be regularly fenced off, using easily moved electric systems. If animals have to be over-wintered on the site, they must be confined to a restricted area.
3. The installation of a moveable water systems (to prevent concentrations of heavy hoof marks in the same area), is also be advisable.
4. When mowing hay, the view from a tractor is ideal for spotting flowering plants growing under the grass canopy, especially when the meadow has been winter grazed. Drivers must be informed and asked to stop and pull these plants.
Our experience of ‘RIP’ and using the ‘ Lazy Dog’ on Ragwort
1. One of the advantages of ‘RIP’ is that managers walk their fields to remove more common weeds like thistles or docks, and will often come across isolated and unexpected ragwort rosettes, while doing this work.
2. Our handwork is skilled, so that the efficiency of operators increases with practice. Skilled operators should have no problem undercutting quotations from operators of spot-spray techniques.
3. In 2001, our gangs were able to work continuously through a month of 7 hr days. In this time they lifted plants from two badly infested sites of 50 and 120 acres.
4. The cooler / moister conditions of Autumn / Spring make rosette removal much easier, and it is possible to remove a good 90% of the annual crop in this way. It is unusual for landowners to consider ragwort control at these times of year, and we consider this to be a mistake. The plant is much more difficult to remove in its’ entirety once the land is sun-baked. Vigorous sections of the white root mass are often left in the ground by traditional late season pulling. In moist earth conditions this is far less likely to be a problem.
Mowing & raking can be used as an emergency form of control, so long as the work is timed so that the maturing plant does not shed seed.
Sometimes the use of a forage harvester is quicker and simpler, although operators have to be wary of the fumes from the chopped plants (do this on a draughty day)
When the rosette infestation is up to 250 + plants to 25sq. metres (say), a front mounted deep-pile weed wiping carpet or brush soaked in Glysophate (or MCPA & 24D mixed), may be an advisable way forward. Tests of this method are ongoing, along with use of the ‘eco- chemical’ (Barrier H). The latter may become a help with young rosettes, if it can reliably kill them in-situ, but (we think) that the amount of chemical used to completely cover the foliage of plants will. It also needs spot-application, dry weather, and approval from English Nature on SSSIs. Given a choice between using chemicals and hand-labour, some land-managers are now opting for the latter, because of costs.
When spraying or weed-wiping is being considered, expenses other than the already considerable chemical costs, must be budgeted for.
1. The purchase & maintenance costs of knapsack, boom sprayer or weedwiper.
2. The costs of time spent mixing and preparing the chemicals or dealing with health & safety protection.
3. The costs of delays caused by the weather and problems created by the need for animal exclusion.