Invasive Alligator weed found in Opotiki orchard

05 May 2016
Alligator weed, an eradication category pest in the Bay of Plenty Regional Council’s pest management plan, has been found in an Opotiki kiwifruit orchard. The invasive weed (pictured), is well established in the Northland area and parts of the Waikato, but is rare or not present elsewhere. Research in Italy claims Psa can colonise and survive on a group of weed species including alligator weed. KVH is following up on this. It was detected by a vigilant AgFirst employee collecting kiwifruit samples for maturity testing. The Bay of Plenty Regional Council will manage and fund an eradication programme. Growers in the Opotiki area are asked to look out for the weed, which is fast-growing and would compete with kiwifruit for nutrients in the orchard. Alligator weed is a persistent aquatic and land weed with dark-green waxy leaves in opposite pairs. Stems are hollow and often reddish in colour. White clover-like flowers, 1-2 cm in diameter, appear during summer and autumn. Although alligator weed does not produce viable seed in New Zealand it can readily spread through stem fragments attached to tractor tyres or other machinery. If you suspect alligator weed is present in your orchard, contact a biosecurity officer at your local regional council. Opotiki growers should contact Sam Stephens, Land Management Officer—Biosecurity, phone 0800 884 880. Click here for a fact sheet about alligator weed.