Chilean needle grass poses a prickly problem
A ban on using Taskforce herbicide in vineyards is preventing Marlborough vineyard owners controlling chilean needle grass, which is a major threat to the sheep-farming industry.
Marlborough District Council biosecurity co-ordinator Jono Underwood said the weed produced seed that penetrated and devalued sheep pelts and meat. It was mostly found on farms and vineyards at Blind River near Ward.
Many grapegrowers did their best to control the weed despite it posing no business threat, Mr Underwood said.
"We don't want to throw darts at them saying they are the main cause of spread."
The threat was highest between November and January when the grass was seeding, Mr Underwood said. This coincided with vineyard mowing, risking machinery picking up and spreading seed.
"We are not going to be dictatorial and say ‘everyone must install washdown points and don't move machinery from this vineyard to that'," Mr Underwood said.
However, they should recognise and report the weed and recognise implications for sheep farmers if it spread.
The council gave Taskforce to owners of properties with needle grass infestations, Mr Underwood said. However, this was not registered for use in food crops, including vineyards where only headlands could be treated.
Growers could use glyphosate (Roundup) instead but this killed only existing plants and seed in the ground continued to germinate.
Cultivating the inter-row area or planting it in species which would compete with needle grass also helped.
Mr Underwood said the council started Taskforce residue trials in vineyards in September and expected early results by mid next year. The council tried to encourage people to control needle grass rather than taking a draconian approach, he said.
In the past year, no enforcement documents had been issued meaning the council did the control then billed the landowner.
However, this was still possible if people were unco-operative, he said.
At a council environment committee meeting last month, rural representative Ross Beech said a lot of people worked in vineyards and he would like to see them taking responsibility for controlling chilean needle grass.
Wine Marlborough chairman Dominic Pecchenino said, "grapegrowers don't want to spread another gorse or broom or any agricultural problem weed".
Needle grass has been found on 2700ha of Marlborough land
The weed grows on 145 properties, mostly at Blind River near Ward
78 have moderate to heavy infestation, including 20 vineyards
Small, isolated areas are found on 67 properties
Most infested land is farmed, although the risk of spread has been reduced
Cattle but not sheep can graze heavily infested areas
- The Marlborough Express