Velvetleaf has been rediscovered in Waikato after the invasive weed was found on two new properties for the first time in five years.
The first new detections of the highly invasive pest plant in the region since 2019 were made in a commercial maize block in wider Matamata and a maize paddock near Otorohanga.
“There is a significant amount of work that has gone into controlling velvetleaf in this region since it was first discovered in 2011, so it is extremely disappointing to have these two new outbreaks,” Waikato Regional Council biosecurity pest plants team leader Darion Embling said.
It is unclear how velvetleaf had spread to these two properties. However, tracing has historically identified machinery and infested maize silage as the most common vectors, he said.
He said it demonstrates the need for continued vigilance by farmers and growers, as well as rigorous machinery hygiene protocols by the cropping sector.
“Our focus is on tracing machinery and crop movement, which is critical to ensuring the risk of spread beyond these properties is effectively managed.”
He said they are working closely with the owners/managers on the affected properties to develop biosecurity farm management plans.
“We are also liaising with the cropping industry, in particular, with a reminder around the ongoing risk of velvetleaf in the Waikato region and the importance of good hygiene practices.
“The discovery of velvetleaf on a property can significantly impact farming businesses, as paddocks are unable to be cropped for some time. So we are doing what we can to support these landowners,” Embling said.
Velvetleaf was first discovered in the region in 2011, but the scale of finds escalated in 2016 with the arrival of infested fodder beet seeds imported from overseas.
The majority of the infested properties are in the north Waikato, Matamata-Piako and south Waikato districts.
Pest plant officers have been working with landowners/managers to develop biosecurity farm management plans to manage the risk of spread on 60 properties.
Velvetleaf is one of the world’s most invasive pest plants, damaging crops by competing with them for nutrients, space and water. In New Zealand, it is an unwanted organism under the Biosecurity Act.
It is an annual broad-leaved herb that grows between 1 and 2.5 metres tall. It has buttery-yellow flowers about 3cm across. It flowers from spring through autumn. The leaves are large, heart-shaped and velvety to the touch. A mature plant can have as many 15,000 viable seeds.
Seedlings are vigorous and the plant grows rapidly in the first few months after germination. Seeds remain viable for up to 60 years. The seeds are spread by water, farm machinery when harvesting grain, through livestock and as a contaminant of grain.
