Kauri in one of the areas most affected by the kauri dieback disease in the Waitākere Ranges are due to get a dose of medicine, as part of a field treatment programme.
Phosphite programme begins
The six-week phosphite programme will begin on the Maungaroa Ridge in Piha in the week of 22 January, and will see several contractors as well as a representative from Te Kawerau a Maki out in the field undertaking the work.
It will involve drilling small holes into a tree, and injecting a dose of the chemical phosphite. Each tree will be mapped by GPS and the dose rate and date of treatment recorded, so progress can be tracked and repeat treatment can be accurately planned.
“Phosphite acts by triggering and boosting the immune system of a tree, to allow it to survive in the presence of kauri dieback disease,” says Lee Hill, Auckland Council’s senior biosecurity advisor for kauri dieback.
“It is also an ongoing treatment, as every tree injected will need to be re-treated in the future.”
“Phosphite is not a cure, nor is it something that can be used to treat every tree in the forest, but is a promising treatment for some kauri stands, or significant trees,” says Lee.
“It is also still vital that people stay out of closed areas of forest and clean their shoes and equipment when they visit the forest, as prevention of spread is one of the keys to protecting kauri.
“Maungaroa Ridge was one of the first spots to have the disease detected in 2006, and it is very widespread there now. It is also a high biodiversity value area, with infection right through the stand, making it a top pick for the treatment programme.
“The dose rate and application method are based on the extensive field trials of Dr Ian Horner of Plant and Food Research. This Waitākere programme aims to develop a field application methodology that can be used in other locations, and monitoring over time will allow us to work out how often a tree will need to re-treated.”
