DETERMINATION OF THE QUARANTINE STATUS OF NEMATODES ON SAMOAN TARO EXPORTS

Samoa was the dominant supplier of taro to the New Zealand market until late 1993 when taro leaf blight (TLB) devastated the Samoan taro industry. Local production for export markets declined dramatically and it is only in recent times, through the Taro Improvement Programme led by the University of the South Pacific (USP) at Alafua, that the development of TLB-resistant varieties has given rise to the possibility of re-establishing exports of taro to New Zealand. Nevertheless, the export market in New Zealand continues to be dominated by taro from Fiji.

The discovery of nematodes determined to be ‘regulated pests’ by New Zealand biosecurity inspectors in taro imports requires the consignment be fumigated. Since 2006 interceptions of nematodes in taro consignments have not been routinely sent for laboratory diagnosis; importers have the option to fumigate any infested consignment directly, avoiding the cost of identification and facilitating more rapid clearance of the consignment to the market. Unfortunately, fumigation reduces shelf life and incurs treatment costs to the importer. Furthermore, treatment would not be necessary if the nematodes were ‘non-regulated’.

Key words: taro leaf blight, nematodes, taro corms, Aphelenchoides, Helicotylenchus, Meloidogyne, Pratylenchus, Radopholus, Rotylenchulus and Xiphinema, fumigation