Network helps curb spread of velvetleaf

Velvetleaf is fast becoming a nightmare for farmers throughout the country.

A national biosecurity network played a key role in managing the recent velvetleaf outbreak which occurred nationwide.

The National Biosecurity Capability Network involves hundreds of organisations and thousands of skilled people which support biosecurity responses and helped implement the 'search and destroy' operation which identified more than 200 properties with velvetleaf.

"Velvetleaf is the world's worst cropping pest, as a weed of arable and forage crops," says Dave Hodges, DairyNZ biosecurity project manager.

"It is an aggressive pest plant that can out-compete crops and seeds prolifically - a single large plant can produce 8000 seeds.

"While it's certainly not welcome on our dairy farms, it is a pest plant which can be managed in pasture paddocks if farmers follow the right processes."

In February, an incursion of velvetleaf occurred in New Zealand from contaminated imported fodder beet seed. Previously, velvetleaf was located in a small number of managed sites around Auckland/Waikato where infestations are related to maize.

"The search and destroy operation identified that velvetleaf is now in 11 regions. The large majority of infested properties are in Canterbury, Otago and Southland, and two-thirds of the infested properties are dairy farms."

DairyNZ joined the network in 2015. Managed by AsureQuality, on behalf of the Ministry for Primary Industries, the network provides extra manpower and other resources to respond to biosecurity threats.

"It's great it is available on standby but we hope instances where it is activated to help manage threats to the dairy industry are few and far between."

DairyNZ's research team was part of the network group to visit properties searching for velvetleaf plants in fodder beet crops.

Technical team leader Hamish Hodgson was joined for the operation by research technicians Anna Clement and Erin Garnet, along with science intern Lydia Farrell.

"Hopefully all of the hard work everyone has put in this year will pay dividends in the years to come," says Mr Hodgson.

"We have made a good start to containing this weed but ongoing management on farms will be required."

Velvetleaf seeds are small and very hardy, can survive silaging and digestion by cattle, and can be spread in feed, by stock and remain viable in soil for decades.

Careful management will contain the weeds and reduce the risk of it persisting on infested farms or spreading further.

All farmers are urged to:

• Check crops for velvetleaf
• If you think you have velvetleaf, mark its location, take a photo and report the find to MPI on 0800809966
• If you have velvetleaf, take steps to keep stock from grazing the area where the weed is present and record your stock movements

- For more information, visit mpi.govt.nz/velvetleaf or dairynz.co.nz/velvetleaf.