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Importation of small seed lots

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In this report, we provide a detailed discussion on an approach which may be used to manage the pathway-level risk of contaminated seed being imported into New Zealand. In any system reliant on sampling to detect contamination, contaminated product may be missed and subsequently imported; this is known as leakage. The proposed approach that we detail provides, at a minimum, an architecture for interrogating the effect of such leakage.

To meet current phytosanitary requirements, MPI has established procedures for the documentation, sampling and testing of imported viable seeds to ensure that weed seeds and seed-borne diseases are not incidentally present in consignments. Most sampling and testing requirements use 2000 – 3000 seed samples in order to achieve 95% confidence of sampling and detecting weeds and diseased seeds at a rate of 0.15% to 0.1%, which does not readily facilitate the importation of small quantities of seed into New Zealand. Often testing is destructive which has a significant impact on the importation of high value breeders seed.

At present there is no option for modification of sampling and testing protocols for seed lots smaller than 2000 seeds or where destructive testing affects the purpose of import or the value of the seed lot. Hence, an alternative testing protocol designed specifically for importing small seed lots is required to maximise the sustainability and growth of the New Zealand seed export industry, while minimising the biosecurity risks to New Zealand. The protocol must be flexible enough to help facilitate the frequent import of different volumes of seeds, different species of seeds and seeds from different countries. The sample size protocol developed in this project may be used directly by the Plant Imports Team at MPI to enable importers of small seed consignments to meet all biosecurity requirements. After appropriate internal and external assessment, the sampling protocol may be incorporated into the Import Health Standard for Seeds for Sowing, which is currently under review. The protocol may also be used to aid risk management decisions for border clearance of consignments.

Author(s):Stephen E. Lane, Rose Souza Richards, Claire McDonald, and Andrew P. Robinson

Published:March 19, 2018

Date added:December 23, 2021