Photo: RNZ / Rebekah Parsons-King
Dairy farmers are gearing up for the beginning of their annual migration as they move cows to new pastures for winter grazing or new sharemilking contracts.
Traditionally, sharemilkers relocate themselves and their herds on or around 1 June - and lots of dairy cows also get sent to greener pastures.
Waikato Regional Council pest plants team leader Darion Embling said farmers need to avoid spreading any diseases or weeds.
The recent discovery of the highly invasive velvetleaf on two new properties in the region was a huge wake-up call for the sector, Embling said.
"It spreads easily through unclean machinery and we are really keen to stop it in its tracks," he said.
"The plants that my team are looking for in the Waikato are noogoora bur, that's an eradication species for us, it impacts on crops."
Velvetleaf - a cropping weed - was another plant they were trying to reduce the spread of.
"Alligator weed is another really significant one where it can impact on any of your waterways, your drains, any streams that are around. Also it can out-compete any grass."
Farmers and contractors need to play a role by cleaning machinery, Embling said.
"That could be the ute, the quad, harvesting machinery ... anything that could have soil on it."
Careful manage of livestock effluent and checking in on stock were key tasks to complete.
"Making sure that when their animals come onto the farm that they can have a quarantine area for 24 hours," he said.
"Give the cows a chance to clean out before they're let loose on the rest of the property."
"The standard to achieve is no visible soil or plant matter which might spread pests or weeds, and this includes on diggers, harvesting equipment, ploughs and undersowers," Embling said.
"It's important these biosecurity practices are adopted by all farmers, and that landowners insist only clean machinery enters their farm gate."
AgriHQ senior analyst Suz Bremner said it was a busy time of the year for dairy farmers.
"May is always busy for cull cows dairy farmers tidy up before moving day," she said.
Embling said there are significant risks if new infestations can take hold.
"Weed infestations can lead to financial loss for farmers and horticultural producers, and seriously harm our natural environment."