In 1984, European blackberry (Rubus fruticosus) was estimated to cost Australians $42 million per year. Today blackberry infests about 5 million hectares nationally and will continue to infest disturbed sites in the absence of adequate control measures.
Identification and characteristics
Blackberry is the name commonly used for a range of closely related brambles.
Blackberry plants within Tasmania vary considerably in factors such as size, vigour, leaf and cane shape, height of thickets, and ability to spread by rooting at cane tips. This variation also affects the susceptibility of blackberry types to control measures such as herbicide use and biological control.
At least nine "species", including the distinctive Cutleaf Blackberry, are known to occur in Tasmania, but there may be others not yet identified.
Blackberries commonly form dense thickets that may reach two or more metres in height and cover tens or even hundreds of square metres in area. The plant has prickly stems or canes which grow from a perennial crown up to 150 mm in diameter. The canes may be erect, arching or trailing and they can reach six metres in length. Individual canes normally live for two or three years before dying off to be replaced by new growth. In an established thicket, up to 70 per cent of the growth may consist of dead canes.
The berries are eaten by many birds and other animals. The seeds survive in the droppings and can germinate in autumn or spring.
Birds are largely responsible for spreading blackberries from one site to another, but a lot of seed is distributed also by water in creeks and rivers.
The canes of blackberries are able to send out roots at the tip where they touch the ground and this is one way in which uncontrolled patches of blackberries keep getting bigger. Apart from 'tip layering', blackberries will grow from root suckers and root fragments. Their extensive root system and their ability to send up new shoots make them very persistent.
Distribtion
Blackberries occur in all settled areas of the State. They grow most vigorously in higher rainfall areas and may be restricted to the edges of creeks and rivers in the drier parts.
The plant flourishes on waste and neglected land where it creates a fire hazard and a haven for vermin. It is particularly prevalent along waterways and on roadsides. Often in association with bracken it can quickly over-run large areas. Under favourable conditions it is capable of spreading in pasture.
Biological Control
Biological control of blackberries using the leaf rust fungus(Phragmidium violaceum), has been achieved with spectacular success at some locations in Victoria. While this same rust species is infesting backberries in Tasmania, the same success is not apparent, possibly because the blackberries growing in Tasmania may be of a different genotype to those growing in other states of Australia, and are consequently less susceptable to the leaf rust fungus.
Status under the Noxious Weeds Act
Blackberries and all Rubus species, except raspberries and the native R. parvifolius are declared Secondary Weeds.
There are no prescribed control measures but DPIF officers are empowered, by the use of Enforcement Notices, to require landholders to undertake any control measures thought to be necessary.
In general, it is the policy of the Department of Primary Industries, Water and Environment that landholders whose land is clean will be given protection, if they ask for it, against the spread of blackberries from neighbouring infested land.
The Department of Primary Industries, Water and Environment also requires that public stock and sale yards should be kept clear of the weed.
 
Note: we are gathering more material for this page, control recommendations and management plans will be included - add a bookmark and call back again.
 
|
