Economic impact of paraquat in Australia
Paraquat herbicides have played an important role in crop protection in Australia for many years. There are no effective alternative herbicides to paraquat with its unique properties and mode of action. It is a vital part of weed control in many crops, both in its own right and in fighting resistance to glyphosate. This article summarises the findings of a recent report, explaining how paraquat benefits Australian farming and the country’s whole economy.
Role of paraquatParaquat is a non-selective
DescriptionA chemical product used for eliminating all types of weeds (annual and perennial grasses and broadleaved weeds).
Authoritative On-line References and Resourceshttp://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University. herbicide controlling a very broad spectrum of weeds before sowing annual crops and in orchards, vineyards and other perennial crops. Paraquat has properties that give many benefits as a herbicide. These include very fast action and rainfastness. The report1 indicated that in Australia several other benefits were regarded by farmers and other stakeholders as being especially valuable:
- Paraquat is bound extremely tightly immediately on contact with soil clay particles and with organic matter. This means that paraquat can be sprayed right up to base of woody plants and that the bark of orchard trees and grapevines provides effective protection. Deactivation on soil contact means that paraquat does not leach
DescriptionThe natural process by which water soluble substances are carried downward through the soil into groundwater.. It can be used safely in sugarcane plantations near the Great Barrier Reef, for example.
- Paraquat is used to fight weed resistance to the critically important herbicide glyphosate. The rise of glyphosate resistant weed
DescriptionThe inherited ability of a plant/weed to survive a dose of a herbicide normally lethal to that species.
Authoritative On-line References and Resourceshttp://www.weedscience.org/in.asp The International Survey of Herbicide Resistant Weeds monitors the evolution of resistant species and assesses their impact. All confirmed instances of new cases are listed. species in Australia is summarised in Table 1. Paraquat has a different mode of action to glyphosate and is used very effectively in the ‘double-knock’ technique.
- Paraquat has many other uses including ‘spray-topping’ to improve the quality of pastures.
|Species||New South Wales||Queensland||South Australia||Victoria||Western Australia|
|Lolium rigidum (Rigid ryegrass)||1997||X||1999||1996||2003|
|Echinochloa colona (Jungle rice)||2007||2009||X||X||2010|
|Urochloa panicoides (Liverseed grass)||2008||X||X||X||X|
|Chloris truncata (Windmill grass)||2010||X||X||X||X|
|Conyza bonariensis (Hairy fleabane)||2010||2011||2011||X||X|
|Bromus diandrus (Ripgut brome)||X||X||2011||X||X|
|Sonchus oleraceus (Annual sowthistle)||2014||X||X||X||X|