Serrated tussock (Nassella trichotoma) is considered by many to be this State’s worst weed. It accounts for a greater reduction in carrying capacity of grazing land than any other weed in Australia.
It is of major significance to conservation systems as well. A native of South America, serrated tussock (Nassella trichotoma) was first recorded in Yass NSW in 1935.
IDENTIFICATION A difficult plant to identify in its early stages. A dense, tussocky perennial grass up to 50cm high. Leaves are fine, tightly rolled, light green in colour except in winter when they are bleached and more of a straw green.
It is at this time the plants are most easily detected. It is also at this time when treatment is urgent required to prevent seed set.
THE PROBLEM Serrated tussock produces vast quantities of viable seeds (click on image, left), which are easily distributed long distances by wind and water, or stock and fodder movements. The plant is of low palatability and low digestibility to grazing animals. The preferential grazing of other pasture plants allows serrated tussock to reproduce freely and continue to suppress competition.
Serrated tussock is a declared NOXIOUS WEED in many parts of New South Wales. It is a very serious weed and early detection and treatment is essential to prevent this weed taking over the property.
According to NSW DPI’s excellent booklet “Noxious and Environmental Weed Control Handbook (Fifth Edition)”, treatments for serrated tussock include:
Non-Chemical Options: Competition: Established of perennial pasture together with good grazing management will assist control. Grub out single plants.
Chemical Options: Permit PER9792
|Flupropanate 745 g/L Various trade names eg Taskforce®||2.0 L/ha 150-200 mL per 100L of water||Boom and aerial application. Spot spray, from September to May. Four (4) month stock withholding period for blanket application.|
|Flupropanate 745 g/L Various trade names eg Taskforce®||1.5-2.0 L/ha||Boom and aerial application. June to August inclusive. Four (4) month with-holding period for blanket application.|
|100-200 mL per 100L of water||Spot spray treatment.|
|Glyphosate 360 g/L Various trade names||1.0 L per 2.0 L of water||Wick wiper application.|
|Glyphosate 360 g/L Various trade names – for aquatic use only eg Roundup Biactive®||0.7-1.3 L to 100 L of water||Spot spray application|
|4.0-6.0 L/ha||Boom spray. Apply to actively growing, stress-free plants.|
|0.75-1.25 L/ha||Spray topping application. Apply to actively growing, stress-free plants.|
|More information is available from NSW DPI see their APVMA Permit PER9792 – expires Nov 2015?|
IMPORTANT: USE OF PESTICIDES – ALWAYS READ THE LABEL Pesticides must only be used for the purpose for which they are registered and must not be used in any other situation or in any manner contrary to the directions on the label. Never use a herbicide in any way contrary to the label recommendations.
DISCLAIMER: The information contained in this web site is based on knowledge and understanding at the time of writing. However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of North West Weeds or the user’s independent adviser. Les Tanner 26/07/2015