Prevention is the most effective method of dealing with weeds. Once a weed has entered an area and become established, eradication is far more expensive and it is likely that greater resources will be required to control its further spread and reduce its impact.
The first step in weed prevention, and the most cost effective means of managing weeds, is preventing the entry of new weeds into Australia. Once a weed has entered Australia, early detection and eradication is crucial to reduce its potential environmental and economic impacts. It is much easier to treat weeds when present in small numbers than when they are well established.
Early detection and eradication requires an awareness and understanding of the factors that favour the establishment and spread of weeds, and applying appropriate management practices that can prevent or reduce the risks. The importance of weed spread prevention has grown with the recognition that the spread of most weeds occurs through similar pathways, such as the movement of goods, animals and vehicles contaminated with weed seeds. Currently, individual states and territories have different approaches to managing the spread of weeds.
In agriculture, the pathways for spread include transported livestock and fodder, contaminated crop and pasture seeds, deliberate introductions of new species, and contaminated machinery such as harvesters and recreational vehicles (including boats which can spread water weeds). There are many ways to prevent weeds in agricultural activities which are well known including:
Plants from commercial nurseries, landscaping suppliers and gardening clubs can also be pathways for the introduction and spread of weeds. Another significant cause of weed spread is inappropriate use and disposal of garden waste. There are a large number of potential weeds in Australian gardens. Private gardens contain over 4000 plant species with weed potential, while botanic gardens hold approximately 5000 species of plants with weed potential. The likelihood that any particular plant will become a weed is difficult to predict; however, the CSIRO has estimated that an average of 10 weed species establish in Australia each year.
Landscapes that contain a diversity of healthy, vigorous vegetation with very little bare ground have the ability, in most cases, to deter weed invasion. It is important to reduce the risk of the environment becoming vulnerable to invasion by exotic species by encouraging beneficial vegetation growth and by avoiding disturbance as much as possible.
Weed prevention : taken from - http://www.environment.gov.au/biodiversity/invasive/weeds/management/prevention.html http://creativecommons.org/licenses/by/3.0/au/deed.en © Commonwealth of Australia 2017