Methods of Coppice Suppression:
Tasmanian Blue Gum trees sprayed with herbicide to cutting the stumps
Coppice will need to be controlled if the site is to be replanted. The main methods for controlling coppice are:
a. Application of herbicide to cut stumps
b. Application of herbicide to coppice foliage
c. Excluding light from stumps
d. Manual shoot control
e. Grazing
Application of Herbicide to Cut Stumps:
Applying herbicide to freshly cut stumps can be the most effective way of controlling coppice. To curtail shoot production and kill stumps, herbicide should ideally be applied to the stump within 24 hours after felling. Herbicide can be applied using spray equipment or a brush. An emerging technology is herbicide spray nozzles fitted to the felling head of harvesting machinery.
Initial trials with Glyphosate and cut stump applications indicate that a concentration of 50% Glyphosate/50% water up to 24 hours, and 100% Glyphosate (360) from 24 to 48 hours after harvesting gave effective coppice control. Lower concentrations were not fully effective, even if applied within half an hour of felling.
Glyphosate bottles
The direct application of Glyphosate to treat cut stumps in a thinning operation is discouraged, because, with these rates of Glyphosate, there is a risk of ‘flashback’ (chemical is taken up, and kills adjacent live trees through root translocation).
Application of Herbicide to Coppice Foliage:
Regenerating coppice should be allowed to grow until it is around 1m in height. Spray the foliage when it is actively growing. If the coppice is taller than one metre it should be trimmed to below one metre and then sprayed. Results indicate that spraying at the maximum rate of Glyphosate is the best option to kill coppice in a single operation. It is essential to use a misting spray that covers every surface of the coppice.
Application of Herbicide to Coppice Foliage:
Regenerating coppice should be allowed to grow until it is around 1m in height. Spray the foliage when it is actively growing. If the coppice is taller than one metre it should be trimmed to below one metre and then sprayed.
Results indicate that spraying at the maximum rate of Glyphosate is the best option to kill coppice in a single operation. It is essential to use a misting spray that covers every surface of the coppice.
Grazing:
Grazing on the sheep farm
Heavy grazing with cattle, sheep or goats in a plantation area after felling, or once coppice regeneration has started should suppress coppice growth. Shoots are repetitively browsed or pushed over and in time the ability of the stumps to produce shoots decreases, which will eventually result in their death. This method is unreliable and may take several years to be effective. Eucalypt coppice is not particularly good fodder and maintenance of stock condition needs to be considered.
What replanting involves:
Second rotation plantation establishment using seedlings needs to be carefully planned, as coppice must be fully controlled before seedlings can be planted. If the decision is made to replant, a number of benefits can be gained including the availability of better genetic material, improved establishment techniques, reduction of fire hazard (if the slash is removed or burnt) and consistent stocking throughout the plantation. In order to replant, both the slash left after harvest and the coppice shoots will have to be managed.
In some Tasmanian blue gum clearfelling operations trees are cut, delimbed and debarked at the stump. This leaves a very high level of slash spread across rows. In clearfelling operations where delimbing and debarking are done at the edge of the plantation and adjacent to the chipping operation, slash conditions and the issues faced in re-establishment are different. In this case it will be important for long term site productivity and nutrition that the slash is redistributed across the site to suit re-establishment operations. Some options for slash management include:
A slash row on dead trees down
