Pasture weed species, including giant rat’s tail grass, have the ability to significantly degrade pastures, resulting in reduced productivity (up to 70% in some cases) and negatively affecting other ecosystem services that are vital for sustainable agri-systems. Whilst a range of control options are available to landholders, a greater desire for using less chemical, in a more targeted manner, is increasingly being demanded among producers and consumers alike. As a result, wick wipers are becoming a more popular tool amongst a number of producers in the Wide Bay Burnett region.

Wick wipers are basically a wick (i.e. carpet) that is coated in a high-concentration of glyphosate that ‘wipes’ across any weed species that are above a particular height (set by the operator), applying just enough chemical to kill the weed. 

Using a wick wiper is a relatively easy process. Below, Eric Dyke, Bundaberg Regional Council’s Senior Land Protection Officer, provides a brief overview of how to use a wick wiper.

Step 1 – Making weeds higher than other more desirable pasture species

As wick wipers apply a concentrated herbicide mixture directly to any plant in contact with the wick, the first step is to make sure that targeted weed species are higher than other more desirable pasture species. To do this, the best way is to increase stocking density on the paddock which is going to be wick wiped for a short period. Make sure you regularly monitor the paddock until a height difference of at least 30cm between the target weed species and the more desirable species is achieved. 

Another method which can assist in gaining required height distance is by slashing the paddock at the beginning of the season. Many weed species, including giant rat’s tail grass, grow faster than other desirable pasture species. Also, by slashing, you also remove any dead grass material which can reduce the effectiveness of wick wiping (due to reducing wick contact area).

Step 2 – Calibrating the wick

Once a distinguishable weed-pasture height is achieved, the next step is to use the wick wiper. No matter what type of wick wiping application method you use, the method of application is always the same. 

Before starting to wick wipe, you will be required to calibrate the wick. To do this, use the wick wiper’s module system to time the pump so that the wick is saturated, but not dripping continuously. If the chemical drips continuously, you run the risk of not only killing all vegetation that comes in contact with the chemical, you will also significantly increase your costs of application. 

The best method of calibrating the flow is to adopt the following principles:

1. If chemical is continuously dripping from the wick, the flow rate is too high and needs to be reduced.
2. If after stopping it takes 10 seconds for the wick to start dripping, the flow rate is spot on.
3. If after stopping it takes 20-30 seconds for the wick to start dripping, the flow rate is too low and needs to be increased.

Step 3 – Application 

When using the wick wiper, the best application process is to double ‘wipe’, meaning that you wipe over the same plant in two different directions. By doing so, it increases the surface area of the weed which comes into contact with the chemical. Increasing the likelihood of control effectiveness.

Step 4 – Monitor and follow up as required

After using the wick wiper, continue monitoring the paddock that has been wick wiped. Results should be observed within one to two weeks (depending upon growing conditions). During this time stock should be left out of the paddock to allow the more desirable pasture species to recover and compete with future weed recruitment. 

Do you want to trial a wick wiper or see one in real life? All local governments in the Wide Bay Burnett hire out wick wipers to local landholders. Why not give them a call?

Additional resources

• Western Australia DAF – Fact sheet blanket wiper for tall weed control