Blackberry

(Rubus fruticosus agg)

Boundary Control Pest

Blackberry is a prickly, usually scrambling, perennial shrub, with fleshy edible fruit. Plants will form impenetrable thickets if unchecked. Stems from a partially buried regenerative crown will root where they touch the ground. Propagation is primarily by birds but also through extension from the parent plant by canes that root at their tips in autumn. Infestations are usually prevalent on lightly grazed areas and wasteland in moist situations. It does not compete with well-managed pastures.

Reasons for the Strategy

The dark leaves and prickly stalks of Blackberry, with small white flowers.

Blackberry causes economic impacts by invading pastoral land and reducing production. Blackberry forms a total barrier of live and dead arching canes and sheep can become entangled in canes and may die. Pieces of stem can contaminate wool; infestations create obstructions to roadside vision and harbour vermin. Blackberry can suppress other plants in scrub and forest margin habitats and also in young tree plantations.

Blackberry is assessed at “8” on the infestation curve. Blackberry is widespread in the Tasman-Nelson region. The distribution of Blackberry has reached a level where the most cost-effective form of control is to require boundary control. This will assist in protecting land that is clear, or being cleared of Blackberry, from invasion from adjacent land by Blackberry. Significant sums are spent by many land occupiers to control Blackberry on their properties, and they should reasonably expect not to have their land invaded by extension of plants growing through a boundary with adjacent infested land. Extensive areas of suitable habitat, and the potential for it to cause significant adverse effects, mean the benefits of boundary control far outweigh the costs.

Objective

To control the spread of Blackberry from adjacent properties to land that is clear, or being cleared of Blackberry, in the Tasman-Nelson region during the term of the Strategy.

Alternative Measures

The alternative option of “do nothing” or relying on voluntary control will not achieve the objective of the prevention of the spread of Blackberry to adjacent properties where there is no Blackberry, or where control is being carried out. Requiring a greater level of control, instead of just boundary control, is not appropriate given the widespread distribution of Blackberry, and that the occupier is the main beneficiary.

Strategy Rule for Blackberry

The occupier shall destroy all adult and juvenile forms of Blackberry located up to 10 metres from the boundary of the land that they occupy where the adjacent property is clear, or being cleared of Blackberry. A breach of Strategy Rule 7.1.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Explanation of Strategy Rule

The Management Agency will limit its intervention to enforce compliance of the rule to occasions when a reasonable complaint is received from an adjoining land occupier. This would require the complainant’s land to be already clear, or being cleared of Blackberry, and that any invasion of the pest plant through the boundary has the potential to cause economic harm to the complainant’s land.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release, or commercially display Blackberry, under Sections 52 and 53 of the Act.