Glyphosate is a non-selective herbicide that kills green, actively growing plants. Careful application is essential to minimise non-target damage.
Characteristics of glyphosate include:
• absorbed through the leaves and green stems
• fast acting—kills treated plants one to four weeks after application
• not residual—ceases to work once it contacts the soil
• no withholding period for grazing stock; however, avoid grazing stock for seven days following application to allow absorption into the plant.
Glyphosate is suitable for all land-use situations and can be used in spot spray and broadacre applications. The optimum time for spot spraying serrated tussock with glyphosate is May to October.
Advantages of glyphosate
• Able to target other weeds at the same time when spot spraying.
• A quick method of killing serrated tussock.
• Nil grazing withholding period.
• When applied accurately, is very effective.
Disadvantages of glyphosate
• Unlikely to affect serrated tussock seed bank levels.
• Broadacre treatments of glyphosate can lead to a monoculture of weeds. Replace the tussock with desirable species to prevent this from occurring.
• Glyphosate is non-selective. Over-spray may open up bare areas, increasing the risk of re-invasion, especially in a dry year.