Purchased Maize Identified as Likely Source of Velvetleaf Incursion
Tracing has indicated that the source of the first velvetleaf find of the 2025-26 crop season, in Auckland, was likely maize purchased in the Waikato region.
Warm, humid weather means velvetleaf and other weeds will start appearing on farms, says Waikato Regional Council (WRC).
Helping to sniff out velvetleaf in Waikato last month was Rusty and his handler John Taylor, from Southland. They visited 12 high-risk farms, finding plants sprouting on eight of them. They’ll be back to do more work in late January and early February.
WRC’s biosecurity pest plants team leader Darion Embling says the wet winter and spring has delayed planting by farmers, but crops are now growing and now is the time to watch for and kill pest plants.
“Most farmers have done pre-emergence spraying but we’re hearing from those previously confirmed with velvetleaf infestations that seedlings are pushing through.
“This is a critical time for killing pest plants; hand-pulling seedlings and post-emergence spraying is essential.”
Landowners and rural contractors should look around gateways and the first 3-4 rows of crops for signs of velvetleaf. They can notify WRC for advice to avoid crop loss.
Seedlings are vigorous, with plants left untouched growing rapidly in the first few weeks after germination. Leaves are heart-shaped and velvety to the touch, and have a distinctive smell when crushed.
Velvetleaf grows up to 2.5m tall and has buttery-yellow flowers as it matures from spring to autumn.
This aggressive cropping weed is among the world’s worst. It competes with crops for nutrients, space and water, and its seeds can persist on farms for decades, even surviving digestion and silage.
