Is heat treatment a viable option for destroying weed seeds in biosecurity risk goods?

  • C.A. Dowsett AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand
  • T.K. James AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand
Keywords: heat treatment, weed seeds, biosecurity, seed devitalisation

Abstract

The prevention of biosecurity threats is an international priority and the development of improved phytosanitary treatment technologies is part of New Zealand’s biosecurity science strategy. Twelve temperature/time treatments were investigated as potential methods to devitalise weed seeds. Six weed species, Digitaria violascens, Eleusine indica, Lepidium virginicum, Plantago lanceolata, Portulaca oleracea and Sonchus oleraceus were exposed to treatments of 50°C, 60°C or 70°C each for 1.5 h, 4 h, or 15 h. The efficacy of these treatments was compared with those of two industry standards: (i) 85°C for 15 h at 40% RH; and (ii) methyl bromide (80 g/m3) for 24 h. The standard treatments were significantly more effective at devitalising weed seeds than the experimental treatments. This study showed that temperatures below 85°C are generally insufficient for devitalising seeds of the weed species examined.

Published
2017-08-08
How to Cite
Dowsett, C., & James, T. (2017). Is heat treatment a viable option for destroying weed seeds in biosecurity risk goods?. New Zealand Plant Protection, 70, 25-30. https://doi.org/10.30843/nzpp.2017.70.21
Section
Vol 70 Biosecurity 2017