Tropical Soda Apple
Noxious weeds

Tropical Soda Apple timebomb

Mass germination of Tropical Soda Apple (TSA) seedlings following recent floods has put Macleay Valley landowners on high alert for the invasive new weed. Landowners are encouraged to survey flood prone areas of their properties and any Tropical Soda Apple plants found should be removed or sprayed immediately before they set seed and spread further. Kempsey Shire Council and the New England Weeds Authority will be undertaking property inspections in the area to assist landowners with its detection.

Tropical soda apple is a native of north eastern Argentina, south eastern Brazil, Paraguay and Uruguay. It was first recorded in Florida in 1987 and was known to infest 10,000 ha by 1990 and half a million hectares by 1995. By 2007 it had spread to nine other states in south eastern USA. In the USA it is a Federal Noxious Weed aptly named "the plant from hell". Tropical soda apple has also naturalised in Africa, India, Nepal, West Indies, Honduras, Mexico and outside its native range in South America.

Tropical Soda Apple was first identified in Australia in the upper Macleay Valley in August 2010; however it is believed to have been in this area for a number of years. Infestations were until the January/February 2013 flood events concentrated in the Macleay from the Georges Creek area downstream to below Bellbrook.

Reports from landholders downstream of Bellbrook confirm that Tropical Soda apple has, as a result of the 2013 flood events, spread downstream via floodwater to at least Sherwood with individual landholders reporting hundreds of plants germinating over the last month.

Nearby small infestations have been found at Wingham, Wauchope, Macksville and near Bellingen. Significant infestations have also been detected in the Coffs Harbour area on the Orara River, and in the Clarence at Glenreagh, Whiteman Creek, Endless Creek and Lawrence areas. Most recently new infestations have been found in the Casino, Bonalbo, Lismore and Tweed areas.

The plant itself is unpalatable to livestock, thus reducing carrying capacity; however, the fruit is readily eaten by livestock. Major vectors of spread include cattle, feral pigs and deer as well as birds, all consuming and translocating the seeds. Water movement of the fruit and seeds also contributes to downstream spread.

Tropical Soda Apple invades open to semi shaded areas, including pastures, forests, riparian zones, roadsides, recreational areas, horticultural and cropping areas in a wide variety of soils. TSA reduces biodiversity in natural areas by displacing native plants and disrupting ecological processes.

Prickles/thorns on this plant restrict native animal and stock grazing and can create a physical barrier to animals preventing access to shade and water. The plant can also restrict the movement of people throughout infected lands through the extremely thorny nature of this invasive plant. 

The plant is a host for many diseases and pests of cultivated crops especially tomatoes. The plant also contains solasodine, which is poisonous to humans.

Tropical Soda Apple (Solanum viarum) is now declared as a Class 1 Noxious Weed across all New South Wales Local Control Authorities (LCA’s).

Class 1 control measures

Weeds Order No 30 specifies the Control Measures applicable to class 1 weeds in cl9(a)(i) and (ii) of the order, which are in summary:

  • The plant must be eradicated from all land in NSW upon which it occurs.
  • Tropical Soda Apple is now a notifiable weed. The requirements in the Noxious Weeds Act 1993 (the Act) for a notifiable weed must be complied with. For class 1 weeds under s15 of the Act this is:

    “an occupier of land (other than a local control authority) on which there is a notifiable weed must notify the local control authority for the land of the fact within 24 hours after becoming aware that the notifiable weed is on the land.” Kempsey Shire Council is the Local Control Authority.

Should you have any questions about Weeds Order No 30 or to report suspected Tropical Soda Apple on your property,  please contact Greg Egan,  Council’s Weeds Officer, on 02 6566 3200

TSA subcatchment groups

A total of 13 subcatchment groups have been formed as part of the Catchment Management Authority funded Tropical Soda Apple project, eight of these are within the Kempsey Shire. The aims of the subcatchment groups is to develop a co-ordinated and co-operative approach for Tropical Soda Apple (TSA) control within the Macleay catchment.

Council will assist by coordinating the groups with on-site inspections advice and assisting groups with TSA weed management plans. Assistance will also be provided with specialist equipment, and chemical. Facilitation and monitoring of group activity will be carried out by Kempsey Shire Council.

Maps of TSA in subcatchment group areas

Note: Yellow square denotes TSA site

Herbicides

A number of herbicides are now permitted for use on TSA under the AVPMA Permit PER 12942 . These include Grazon Extra, Picloram and Triclorpyr (Grazon DS) with Metsulfuron Methyll (Brush off) and Glyphosate with Metsulfuron methyl. For full application directions read the permit and critical use comments.

When mature plants are sprayed it appears that the fruit continue to ripen and produce viable seed. Where this is the case, particularly in situations where TSA plants are uncommon, fruit should be manually removed to minimise the risk of further germination.

Landholders in flood prone areas of the Macleay need to conduct immediate total inspections of their properties to identify and control all Tropical Soda Apple seedlings that may have germinated on flood effected country as a matter of urgency as plants not controlled will commence to flower, fruit and set seed during August.

For assistance with identification and control options for Tropical Soda Apple, please contact Council's Weeds Officer or Department of Primary Industries office.