By Maia Hart, Local Democracy Reporter
The extent of how far-reaching wild kiwifruit is in the Marlborough Sounds is under the microscope - as the council considers whether it needs to be included in its pest management plan.
File photo. Photo: 123rf
Historically planted in "old-homesteads", wild kiwifruit has spread to parts of the Marlborough Sounds - carrying with it the potential to harm native plants.
A review of the Marlborough District Council pest management plan was undertaken in 2017.
Kiwifruit Vine Health submitted on that review, and in 2018 asked the council to include wild kiwifruit as a recognised pest, saying it impacts indigenous biodiversity, and is also a reservoir for disease organisms such as Psa and pests such as fruit flies and stink bugs.
Marlborough District Council senior biosecurity officer Rob Simons this week said the council was not in a position to include wild kiwifruit in the council's pest management plan in 2018, because they did not know enough about it.
"But what's happened since then, through other work in the Marlborough Sounds, we have found kiwifruit plants, and from those plants we have actually discovered satellite infestations of wild plants," Simons said.
"That's led us to investigate how much of it is out there, so we're currently trying to build this picture of ... where is it growing, how much is there, and can we actually control it with our current resources?"
He said through the Jobs for Nature project, a $1.219 billion programme introduced as part of the Covid-19 response, some "control work" had been undertaken to remove wilding plants.
The top of the south Jobs for Nature programme "restoring and protecting flora/Kotahitanga mō te Taiao" was the group helping to remove the plants.
Simons said at this point in time, this was not considered a council project, as they were still in the "information gathering" stage.
"We are using that information to potentially build a proposal to amend the regional pest management plan, to incorporate kiwifruit as a new programme," he said.
He said all control work at the moment was being undertaken in collaboration with landowners.
"So there's no regulatory backing, it's just a voluntary thing," he said.
"If however, through our investigations, we find that yes kiwifruit is becoming a bigger problem, and we run into situations where wilding plants cannot be removed or managed because land occupiers do not want us to, then council will look at the possibility of including it as a regional pest management plan pest," he said.
This would mean it carried regulatory backing, Simons said.
He said the infestations they were finding were existing kiwifruit vines, that were planted like "an apple tree in the backyard", typically in old homesteads.
"There's one site, near Manaroa that we know of where kiwifruit has spread some distance from a parent plant and the seedlings are actually popping up on an old forestry block which is regenerating into native bush," he said.
"There's an opportunity now, in some form, to actually take action to prevent it from becoming a bigger problem in the Marlborough Sounds."
How to prevent wild kiwifruit
Growers - Remove unpicked fruit from vines and mulch as soon as possible. This prevents mass feeding by birds and allows the fruit to compost as quickly as possible.
Post-harvest operators - Cover bins of rejected fruit to prevent birds feeding on ripening fruit.
Farmers - Cover stockpiles of fruit with shade cloth, windbreak netting or something similar, to prevent birds from getting to any fruit. Feed out only what will be eaten by stock at one time to prevent birds from eating leftovers.
The public - Be careful with the disposal of kiwifruit, particularly while out in the bush.
Local Democracy Reporting is Public Interest Journalism funded through NZ On Air