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Case study - Paterson’s curse (Echium Plantagineum L.)
Also known as Salvation Jane, Riverina bluebell, blue weed and purple bugloss, Paterson ’s curse originated from Western Europe and the Mediterranean areas. It was first recorded in Australia in 1843 as a garden plant.
Photo sourced from Weed Information at http://www.weedinfo.com.au 
Paterson ’s curse is a major pest in winter pastures throughout southern Australia and is classified as Australia ’s worst broadleaf temperate pasture weed. It is a winter annual herb that often becomes the dominant pasture species.
Paterson ’s curse is considered a weed because:
- it contains liver toxic alkaloids
- it reduces the pasture value as it out-competes the more nutritious and palatable pasture plants
- it reduces soil fertility
- it invades disturbed natural areas and replaces natural vegetation
- some people are allergic to the pollen and bristles on the plant.
Depending on the area in NSW, Paterson ’s curse is classified as W2 or W3 noxious weed in NSW. The Noxious Weeds Act 1993 defines W2 and W3 noxious weed control as follows:
- W2 – The weed must be fully and continuously suppressed and destroyed.
- W3 – The weed must be prevented from spreading and its numbers and distribution reduced.
Description
Properties
Life cycle
Prevention
Treatment methods
Biological control
Other forms of control
Description
Paterson ’s curse is an erect, hairy annual that can be occasionally biennial. It generally grows 30-60cm in height and reproduces from seed.
Rosettes
Hairy, egg shaped leaves that may grow to a length of 30cm.
Roots
Stout taproot with numerous laterals.
Stems
Erect, maybe up to 1.5m high, light-green, bristly, stout, branching mainly towards the top.
Photo sourced from Weed Information at http://www.weedinfo.com.au
Leaves
Green to light green, alternate, hairy and thick.
Flowers
Purplish-blue funnel shape or very occasionally white or pink, appearing September to December.
Photo sourced from Weed Information at http://www.weedinfo.com.au
Seeds
Dark brown to grey, tough, angular, beaked, 3mm long, 2mm wide. Large numbers may accumulate in the soil over a number of years.
Dispersal
Paterson ’s curse is spread by seed. Seed can be spread by vehicles, farm implements, humans, animals, water, wind, hay, silage, wool and contaminated commercial seed.
Properties
Paterson ’s curse is poisonous to grazing animals, especially pigs and horses, as it produces pyrrolizidin alkaloids. Sheep, cattle and goats are least affected.
Paterson ’s curse is a winter annual that has the ability to germinate any time of the year, given the right conditions. It forms a flat rosette which can out-compete other germinating plant species. It is a prolific seed producer and rapid spreader that develops a large taproot, making it resistant to drought and an ideal weed.
Paterson ’s curse is an invasive weed that produces tens of thousands of seeds with seed longevity greater than seven years.
It can be used as a pasture plant as it is relatively nutritious in terms of digestible nutrients for those animals for which it is suitable.
Life cycle
All stages of growth can be found on Paterson ’s curse throughout the whole year, although it commonly germinates and develops rosettes with the first autumn rains. It begins to produce flowering stalks in late winter and commences flowering in early September. The first mature seeds are produced four to six weeks after flowering commences. The plants die after flowering. Although flowering is at its peak from September to December, it may start in July and extend to January.
Prevention
Preventing Paterson ’s curse from spreading to uninfested areas is as important as trying to control it once it has established. Paterson ’s curse spreads only through the movement of seeds. Common methods of seed dispersal include:
- seed contamination of hay or grain fed to stock during drought
- certified seed used for sowing crops and pastures containing Paterson ’s curse seed as part of the unknown seed component
- seeds being carried by animals to new areas. Some seed can pass through the digestive system without losing viability.
- run-off water carrying seeds to lower country
- vehicles, machinery and stock carrying seeds to new locations.
Treatment methods
Regardless of the treatment method implemented, pasture establishment is vital in the follow up. A strong competitive pasture will reduce the chances of the re-establishment of Paterson ’s curse.
Biological control
Biological control of Paterson ’s curse involves the use of the weed’s natural enemies for its control. Biological control agents need to have a narrow host range so that crops or native plants are not significantly damaged. The aim of biological control is to reduce weed infestations - the weed is never eradicated.
Current biological controls of Paterson ’s curse include:
- leaf-mining moth (Dialectica scalariella), released 1988-91
- crown weevil (Mogulones larvatus), released 1992
- root weevil ( Mogulones geographicus), released 1993
- flea beetle (Longitarsus echii)
- flower beetle (Meligethes planiusculus)
- stem boring beetle (Phytoecia coerulescens)
Other forms of control
Competitive pastures
Vigorous, perennial, grass based pastures are best as they compete strongly for the moisture that is needed by Paterson ’s curse to germinate. In summer and autumn it is important to minimise grazing pressure on infested pastures in order to maintain a good ground cover and prevent the bare patches that provide ideal conditions for Paterson ’s curse to re-establish.
Grazing management
The main emphasis of grazing should be on reducing Paterson ’s curse seed set because re-emergence of this annual weed is dependent on seed availability. Heavy grazing (8-10 times the normal stocking rate) during spring and early summer can suppress seed set. When grazing, it is important to remember the presence of pyrrolizidine alkaloids, which are poisonous to stock. Non-pregnant, non-lactating adult sheep are best suited to grazing Paterson ’s curse. Grazing of cattle, horse and pigs should be avoided.
Spraying
There are selective herbicides registered for Paterson ’s curse control in various pastures and crops. They are most effective when used while the weed is at the small rosette stage.
Spray-graze techniques
This involves the application of herbicides at reduced rates so as not to reduce the palatability of the weed, which is then heavily grazed. The herbicides are applied at the early rosette stage. Depending on which herbicide is used, it may be necessary to hold stock from grazing. The pasture should then be grazed heavily at eight to ten times the normal stocking rate with dry sheep. Grazing should be continued until the Paterson ’s curse has been significantly reduced but not to the point that the desirable pasture is threatened.
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