A fast-spreading weed that can block drainage and irrigation systems has spread to a new area of New Zealand's apple and kiwifruit-producing Bay of Plenty region.

Bay of Plenty Regional Council biosecurity officer Des Poole said the alligator weed could have spread from waterways to the Eastern Bay, where it has been found in farmland near Taneatua.

He said it had the potential to form one meter-deep roots that are difficult to manage and could seriously impact on farming activites.

"It may well have been brought to the site as a result stock movement, or on contaminated machinery," he said.

"Restrictions were immediately put in place to prevent it from spreading. This included fencing off the affected area and stopping stock from accessing the area.

"This latest incursion also serves as a reminder to landowners and contractors to ensure all farm machinery is clean before leaving a property."

The weed has also been found in other parts of the Bay of Plenty, as well as Auckland and Waikato. The Waikato Regional Council says if farmers try to cut the weed themselves, the small cut fragments can easily re-grow.

"Take special care not to disturb it or transport it to new sites. It can spread by water movement such as floods or tides, from soil movement, and equipment such as diggers, farm machinery, eel nets and boats," the council says on its website.

"Alligator weed does not set seed in New Zealand but spreads aggressively from even the smallest stem fragments. It can double in area in less than two months.

"It can out-compete pastures and crops, affecting farm production and profit."

Photo: www.envbop.govt.nz

Source: www.freshfruitportal.com