Thomas Malthus, an English economist and demographer, in 1798, proposed a theory that population growth will always tend to outrun the food supply and hence population growth needed to be controlled to prevent dire consequences. ..

Australia has over 874,000 km of roads which translates to 1.75 million km of roadsides with vegetation that must be managed. Roadsides can be a harbour for important weeds and a potential avenue for their spread. ..