Local Land Services North West* is funding a round of herbicide trials on harrisia cactus near Goondiwindi. Conveniently located on the open TSR adjacent to Gunsynd Way, the (drive-through) trial site is just opposite the Boomi Rd turnoff. It’s open to the public for on-going viewing. Twenty one (21) different herbicide mixtures have been applied to a total of 60 plots, all signposted. (*LLS northern office located in Waggamba Square, Goondiwindi Qld)
The first set of ten (10) mixtures was replicated Mar-Jun-Sep-Dec to determine optimum application times. Most of the other mixtures were also applied at 3-monthly intervals, but with an emphasis on more options for effective winter application (for use in between the main peak farming periods).
Below, with kind permission of the LLS North West, are links to the three documents needed to follow the progress of these trials.
Please be aware that the individual “scores” as shown so far are a guide only! It’s easy to kill the top of the plant; it’s what happens to the root system that counts. That’s why the trials have been extended to 24 months.
PREVIOUS HARRISIA TRIALS?
Herbicide trials have been conducted in (NSW) Moree, Gwydir and Inverell Shires since 2008 – thanks to special funding received from the then Border Rivers Gwydir Catchment Management Authority (now Local Land Services) through the Australian Government Caring for Country scheme.
The best results brought forward from these trials were the basis for an extensive trial put down on the Billings family property “Bridgewater” 30 k’s SE of Goondiwindi (our sincere thanks to Mr Ed Billing and Inverell Shire Council for their support with this project). Commenced Dec 2013 and finalised Feb 2015, the results of this trial was summarised in a document provided by North West Weeds – PDF copy attached: Harrisia trials Bridgewater BW3 Dec 2013 to Feb 2015 Final.
- Notes on the BW3 trial summary to Feb 2015:
20g metsulfuron methyl plus 100mL wetter to 100L water is very effective, especially for large infestations because this basic mixture is so inexpensive – less that 3 cents a litre. But, the downsides:
(a) not suitable during cooler weather especially if plants approaching fruiting stage (unless adding a picloram/triclopyr product – see Permit PER80069 for more info on rates)
(b) metsulfuron can cause collateral damage to trees especially when we are talking high volume applications – for example, wilgas are shallow rooted and very susceptible – box trees are also a problem especially if there is heavy rain soon afterwards to wash the herbicide further into the ground.
- Access® and diesel (1 to 60) or Garlon® and diesel (1 to 75) mixtures are both good for treatment of isolated plants because they stay mixed for a longer period. Expensive, but very practical for a spray pack in the back of the quad/ute when you come across a new plant. Also very appropriate to use during winter/cool periods
- Grazon-type herbicides (Triclopyr + picloram) at the (standard) rate of 500 mL per 100 litres water appear to be TOO STRONG, taking out the top of the plant before translocation into the root system is complete – thus leaving the way open for excessive regrowth.
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.