A long-time aim for wilding tree control has been to find cost-effective foliar herbicides to spray from the air.  Treatment from the ground, where good foliar coverage can be more readily obtained, is relatively easy, but getting such coverage from the air is much more difficult.  For this and other reasons, past results from aerial spraying of wildings have usually been variable, with the predicted success elusive.  Hopefully, we may soon be able to report differently.
This year new aerial spraying trials have been established at Mid Dome in Southland, near Queenstown in central Otago and at Pukaki and Craigieburn in inland Canterbury.  The main target has been contorta pine, but dwarf mountain pine (Pinus mugo) and Douglas-fir have also been included.  At the first three sites, DOC has combined with Scion to use a range of chemicals, including glyphosate, metsulfuron, Reglone (main active ingredient diquat), Tordon (picloram) and grazon (triclopyr), while at Craigieburn, Andy McCord of Technical Forest Services Ltd (www.techforest.co.nz ) is testing out reglone, focussing on water quality and pH together with new additives and spreaders.
As results become available, they will be placed on this website.