Macquarie Valley W.C. & Lachlan Valley W.A.C.

Parkinsonia

Botanical Name:

Parkinsonia aculeata

Other Common Names:

Declarations

Class

Regions

Class 2

Bland Shire Council,Bogan Shire Council,Bourke Shire Council,Brewarrina Shire Council,Cabonne Council,Castlereagh Macquarie County Council,Central Darling Shire Council,Cobar Shire Council,Cowra Council,Dubbo Regional Council,Forbes Shire Council,Lachlan Shire Council,Mid-Western Regional Council,Narromine Shire Council,NSW DPI - Lands - Far West Region,Orange City Council,Parkes Shire Council,Upper Macquarie County Council,Weddin Shire Council,Wellington

Landholder Responsibilities:

The plant must be eradicated from the land and the land must be kept free of the plant

Why Is It Bad?:

Is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread,and economic and environmental impacts. It threatens rangelands and wetlands around Australia. If left untreated it displaces native vegetation and reduces access to land and waterways. Parkensonia provides refuges for feral animals, especially pigs.

Identification

Habit:

Tree

Leaves:

Parkensonia can grow to 8m. It can be single or multi stemmed. The smooth green stems are slender and tend to droop and zigzag. Parkensonia leaves consist of a falt green leaf stalk up to 300mm long and 2 - 3 mm wide with numerous small (4-10mm) green oblong leaflets staggered along both sides. the leaf base is protected by sharp, recurved spines, 5-15mm long, which persist in older branches.

Flowers:

Parkensonia flowers are about 20mm across, with four yellow petals and one errect orange or orange spotted petal.

Fruit:

Seed pods (30-130mm long) are straight with bulges around seeds and points on both ends, and are straw brown when ripe. They generally contain 1 - 4 seeds, but occasionally up to 11. Seeds are olive green to brown and oblong shaped (10mm by 4mm)

Roots:

The roots are generally shallow.

Control Methods

Manual Removal:

Small parkensonia plants can be relatively easily removed by manual means (hand pulling or grubbing with a mattock) Larger plants can be bulldozed, stickraked, blade ploughed or chain pulled. The roots must be removed to a depth of about 200mm to prevent root growth. Mechanical control is more cost effective than chemical control.

Chemical Use:

There is a wide range of herbicides registered for Parkensonia control, with several different application methods. Herbicides are useful for controlling dense high priority infestations but may be too expensive for widespread infestations. Foliar spraying provides effective control for seedlings that are less than 2m tall and actively growing. Larger trees can be treated with a liquid or granular herbicide applied near the roots just prior to the wet season in northern Australia. Basal bark and cut stump treatments generally provide more effective control than foliar spraying. They are the main methods recommended for use near waterways. When applying the basal bark technique to stems up to 150mm diameter, drench the herbicide around the trunk to a height of 300mm above the ground. For larger trees spray up to 1m above the ground. When using the cut stump technique, be sure to swab the entire cut surface of the stump immediatley after cutting as this ensures tht the herbicide reaches the roots.

Fire:

Fire kills seedlings and seeds on the surface and is an excellent form of floow up control after mechanical or chemical control. Little is known about the timing or conditions that are required to get good kill rates.

Slashing & Cutting:

Biological Control:

Grazing:

Cultivation & Scalping:

Blade ploughing gives excellent kill rates and is effective in treating large, thick infestations. Chain pulling kills mature trees, but many smaller plants are just bent over and straighten up once the chain has passed over. If the roots are not reoved, parkinsonia can reshoot, producing multiple stems fro the base. These multi - stemmed plants are actually more resilient and harder to remove.

Smothering:

Solarisation:

Competition:

Monitoring:

Images

Click an image to view a larger version

Image Credit: Don Mackenzie Bourke Shire Council

Macquarie Valley Weeds Committee & Lachlan Valley Weeds Advisory Committee

Parkinsonia

Declarations

Identification

Control Methods

Images