|Botanical Name||Senecio jacobaea|
IdentificationRagwort is a biennial or perennial herb. Normally producing a rosette in the first year of growth and then a flower stem in the second year which is topped with bright yellow flowers. After flowering and setting seed ragwort dies. Plants that are damaged will regenerate from the crown, converting biennial plants to perennials.
HabitatsRoadsides, disturbed areas, river beds and poorly managed pasture.
Impact to Biota and EcosystemsPasture invasive, leading to reduced pasture production on dairy and beef properties as cattle avoid ragwort. Sheep will eat ragwort, normally tolerating the poison that affects the liver of grazing animals.
Dispersal Routes, Vectors, Infestation SourcesSeed is the main method of invasion, being dispersed by wind, water, animals, vehicles and in hay. Most of the 250 000 seeds that can be produced by each plant falls within a few metres.
Grubbing or mowing is not recommended as this can stimulate the development of perennial plants. Ragwort can be hand pulled at the late flowering stage.
Dispose of by deep burial or burning.
Seedlings or small rosettes can be boom sprayed with Pasture Kleen @ 2.5 - 4.0L/ha.
Larger plants can be spot sprayed with Tordon Gold @ 300 - 500 ml/100 L water
Ragwort seed fly was released in New Zealand in the late 1930s.
The first releases of Cinnabar moth were made in 1929.
Ragwort flea beetle were imported in 1981.
Ragwort crown-boring moth and Ragwort plume moth were released in 2006
Good pasture management is the key to control as young seedlings are very susceptible to pasture competition. Stock management should aim at preventing overgrazing, especially in summer.