Mode of Action
Rootfoam is a wettable power formulation which contains 850 g/kg of the active ingredient, called dichlobenil. This ingredient works by inhibiting the formation of cellulose in plant cell walls. This inhibition causes the cells to loose their elasticity. The cells are not able to function correctly – that is elongate – instead they swell in all directions and then burst. Dichlobenil is most active at the site of cell division, known as the meristem.
Dichlobenil can be considered as a selective herbicide in the sense that it will only affect growing plant tissue and not plant tissue which is already established.
Using Rootfoam
When using Rootfoam, it is essential to ensure that any cracks and joints are penetrated by dichlobenil. It should never be applied to storm water or sullage lines where run-off cannot be contained or pumped away for disposal to sewer.
Rootfoam can be used in two ways; through foam spray application, or by line soaking.
In the spray application method, the foam carries the dichlobenil to the roof and side walls of the line being treated. The dichlobenil is deposited on the walls of the pipe when sud-break has taken place. It is critical that the equipment used has been designed for this purpose and the expansion factor of the foaming agent is known at a given pressure so that flow rate and pressure can be maintained.
The equations to the right are used to determine how much water is required
(Equation 1) and what application rate of Rootfoam is required (Equation 2) to treat a given length of line.
Mixing and application procedure
Add half the required water to the mixing tank. Then with the tank agitator running, add Rootfoam and the foaming agent before adding the balance of water. Block off the lowest point of the highest section of pipe to be treated or the outlet point of a single line.
To avoid back pressure and loss of foam up branch lines and observation vents, these should be blocked off with inflatable valves or the hose and nozzle pushed to the downhill end of the line to be treated. Commence foaming operation and withdraw the nozzle back down the line as the foam is formed. If correctly timed the batch mix should be completely depleted as the nozzle is withdrawn down from the pipe. Remove block plugs and proceed to next down-stream pipe-length.
Application by line soaking
In order for Rootfoam to be effective, a concentration of 100 ppm (22 grams of product is needed per 100 litres of treatment wash) is required for treatment of the total content of the line.
Block off the lowest point of the highest section of pipe to be treated or the outlet point of a single line. Leave the line to soak for one hour. During this time the level of water may gradually decline. If this occurs, topping up is not required in this situation.
Release the block plug from the end of the line, and if treatment of the next suction line is desired, a block plug should be inserted before releasing the chemical from the first section. If required, additional water may be added to the suction line. A concentration of 100 ppm must be maintained in the addition treatment water.
If the treatment water cannot be reused, it must be pumped back into the tank and disposed of correctly. This is of particular concern in the treatment of stormwater drains.