Page 4726 - Week 15 - Thursday, 16 December 1993
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St John's Wort
MRS GRASSBY: Madam Speaker, my question is to the Minister for the Environment, Land and Planning, Mr Wood. What threat is posed to the ACT by the weed St John's wort and what action is the Government taking about it?
Mr Humphries: Cop that, Bill Wood.
Mr De Domenico: Zero in on this one.
MR WOOD: Madam Speaker, the Opposition wants to treat it lightly; but the fact is that that weed, St John's wort, is a significant problem in large parts of New South Wales and Victoria, and also in the ACT. For those who have a great concern about the quality of our environment, this is a matter of importance. As they drive around the town members may well see St John's wort now in flower. This has become a greater problem in the last 10 years. Before about 1980 it was isolated to some parts of Canberra. Some people speculate that, since the drought in 1983, for some reasons that are not clear it has expanded considerably.
One of the problems we have with it is control. It is one of those plants whose above-ground parts are relatively short lived but which have a large and long-lived store of underground seed that is very difficult to affect by control methods. Achieving effective control, therefore, requires the prevention of seed formation until the seed store decomposes in the soil, and that is a period of some six to 10 years. So control is particularly difficult. Its main threat to environmental values depends on its ability to invade intact native areas. It is certainly the case that the weed invades disturbed areas and seems not so much to invade intact native forests and vegetation.
Over a period there have been a couple of measures to try to control it. Obviously they are not being very successful, but those efforts will continue. The agriculture and landcare section in my department is conducting field trials of a selective herbicide. In doing that we are consulting with the manufacturer in the interests of developing more effective selective control. We would rather avoid the use of herbicides if we could, but it is a measure that has to be tried. There are two biological control agents in place on St John's wort plants in the ACT.
Mr Moore: I raise a point of order, Madam Speaker. I draw your attention to standing order 117(e)(ii) and to the fact that this matter is before a committee at the moment. I chair that committee, Madam Speaker, and it is not such a problem, but I think he should finish.
MADAM SPEAKER: Thank you, Mr Moore. Proceed, Mr Wood.
MR WOOD: Madam Speaker, I thought Mr Moore might have been interested in this. His committee is doing a good job. I might point out also that he is relying, quite properly, on a great deal of advice from the department I am talking about. They provided invaluable information and they have shown leadership in this area. I am about to finish, Madam Speaker - for Mr Moore's benefit. A mite was released by CSIRO in 1991 and that is now in place, but it is also clear that neither the herbicides nor the biological controls at this stage have been particularly successful, because the weed is continuing to expand. It may be the case that it could have been a lot worse if we had not had those measures in place.
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