Pest management is an important service provided to the community. Pest and weed invasion threaten the biodiversity of the City's conservation reserves and affects the function, community use and amenity of our public spaces and public infrastructure.
Integrated Pest Management
The City is committed to the responsible use and reduction of pesticides within the environment and is implementing a range of chemical-free initiatives to manage pests and weeds, a maintenance process generally referred to as Integrated Pest Management. The City has reduced reliance on chemicals while ensuring weeds and other pests are managed responsibly and that pesticides and herbicides are only used once all alternative options have been explored.
Methods for weed control
The City maintains large areas of land, including many facilities and assets. This means a variety of pest and weed control methods are needed to ensure effective control, including:
Prevention: alternative designs and management processes making it harder for weeds and pests to establish and complete their life cycle
Cultural controls: modifying a pest’s habitat to make it harder for weeds and pests to complete their life cycle and providing enhanced habitats for natural enemies or competitors
Physical and mechanical controls: super-hot water steam, hand pulling, mechanical cutting, mulching and trapping of some feral animals
Biological control: introducing natural enemies of weeds and pests, which may include conserving habitat for natural enemies or the use of biological sprays Chemical control: includes herbicides, fungicides, pesticides and some poison baits.
Given the scale of land managed by the City, chemical free alternatives are not always feasible, however, pesticides may be selected for use. Only chemicals registered for use by the Australian Pesticides and Veterinary Medicines Authority are used. These are applied in a safe and responsible manner, in accordance with label directions and best practice as prescribed by the Western Australian Department of Health. The City also notifies residents of pesticide use through a range of channels and maintains a Pesticide Notification Register.
The City features unique bushlands, riverine areas, lakes and wetlands. Management and conservation of these areas is important to the City as they support sustainable ecosystems, support biodiversity improvements and provide habitat for wildlife. The City may use a range of methods to minimise environmental weeds and pests in these areas, including:
Introducing pest predators such as leaf hopper insects and/or other biological agents such as rust fungi to control certain invasive weeds.
The use of selective herbicides that do not affect native plants, where there are dense infestations of non-native grasses in bushland
Spot-spraying of systemic herbicide for weeds with underground storage structures in the form of bulbs, corms and rhizomes, including Black Flag, Fumaria, Oxalis and Gazania
Hand brushing of cut trunk bases with herbicide to control sprouting of woody weeds and feral grasses
The use of organic herbicides including vinegar, pelargonic acid and neem seed oil are to reduce reliance on synthetically derived or extracted herbicides such as Glyphosate.
Turf renovation and maintenance undertaken on the City’s sports fields, parks, golf greens and reserves aim to support healthy and vigorous grass cover, which helps minimise weed infestation and pest and disease impacts.
The use of organic fertilisers and amendments such as Seamungus and Bactivate are used to improve soil health with the activation of beneficial soil bacteria
The use of soil and leaf tissue analysis, undertaken up to four times a year to ensure optimum health of the turf
Topdressing with high organic soil mixes to promote turf health.
The use of spot pesticide application to target specific weeds with a ‘weed wand’ to minimise broad acre spraying
The targeted application of selective herbicides within broad acre turf areas to control invasive and nuisance weed species such as Onehunga or Bindi weed.
The City undertakes surveys each year to record the extent of pest infestation, ensuring pesticides are only used where necessary.
Streetscapes & Gardens
Regular maintenance of City-owned verges, medians, gardens, pathways and facilities helps minimise weed infestation and pest and disease impacts.
The application of mulch to limit light and prevent weeds from growing
The use of watering and nutrient supplements to facilitate vegetation health and rapid growth maximising weed suppression.
The controlled application of Glyphosate within road reserves to reduce weeds in pavements, paths and kerbs.
Physical and Mechanical Controls
Alternate control measures, including ‘Super-Hot Water / Steam, reducing herbicide use in areas of high pedestrian activity (commercial precincts, adjacent to schools, hospitals and nursing homes).
The use of the term ‘pesticides’ is generic and includes herbicides, insecticides and fungicides. Pesticides within the context of this information can be defined as substances or organisms used to kill, incapacitate, repel or inhibit the growth of pests.
Integrated Pest Management (IPM) refers to management practices developed to provide effective pest control or minimalisation whilst seeking to minimise impacts to human health, the environment and other organisms. IPM is both a procedure and decision-making process, a long-term management approach that combines the following key aspects:
Identification and Monitoring - IPM identifies the pest, its lifecycle and monitors pest populations throughout the year. This differs from traditional pest management, which may rely on the preferred application of chemicals.
Acceptable Threshold Levels - IPM assumes some tolerable pest and weed population levels and acceptable levels of impact to aesthetics or functionality. Pest control will only occur if these thresholds are exceeded. This approach allows some seasonal pest presence within the environment.
Treatment Method Selection - If treatment is required, an IPM decision making model will indicate the best method and timing based on review of the following criteria:
Least disruptive to natural enemies of pests and natural controls
The Australian Pesticides and Veterinary Medicines Authority (APVMA) controls and regulates the use of pesticides, including herbicides. The APVMA assesses chemical products for toxicology, efficacy, environmental impact, residues, breakdown times and potential health impacts.
The WA Health Department controls herbicide operations through the "Health (Pesticides) Regulations 2011" and associated guidelines. The legislation permits the City and all WA Local Government Authorities to use registered and approved herbicides in their weed control programs, in accordance with the product instructions and Safety Data Sheets.
The City is required to comply with all other requirements of the Health (Pesticide) Regulations 2011 (under the Public Health Act 2016), for:
safe storage, use, transport, decontamination and disposal of pesticides
public notifications and works site signage
registration and licensing for pesticide management.
The Western Australian Local Government Association (WALGA) is a local government industry representative which assists the industry, facilitates a local government Herbicide Use & Integrated Weed Management Working Group with the objective of developing a best practice integrated weed control guide, weed management related community information resources and weed management training opportunities. The City of South Perth is a participant on the working group. In the interim WALGA recommends that local governments are guided by industry best practice, legislated requirements and regulatory authority advice.