Effects of phosphine (ECO2FUME®) on ‘Hass’ avocado fruit quality and target pest mortality

ABSTRACT

Phosphine (PH₃) is a methyl bromide alternative with the potential to control surface pests of New Zealand avocados as a pre-export disinfestation treatment. ‘Hass’ avocado fruit were treated with PH₃ (as ECO2FUME® (2% PH₃, 98% CO₂ (w/w); Cytec Industries Inc.)). at 500, 750 and 1,500 ppm for 24, 48 and 72 h at 5–6 °C, along with vials containing mould mites (Tyrophagus communis) and greenhouse thrips (Heliothrips haemorrhoidalis). Fruit were then stored at 5 °C for three weeks, external quality assessed, and internal fruit quality assessed after ripening at 20 °C. PH₃ treatments had no impact on external fruit quality, nor on skin colouration, and only minor increase in softening compared to control at 24 h, but not 48 or 72 h. Complete (100%) mortality was achieved for thrips at all PH₃ concentrations for 48 h. However, only ∼50% mould mite mortality was achieved at the highest PH₃ concentration of 1,500 ppm for 72 h; although this treatment did provide a significant reduction in rots and internal disorders. This initial study demonstrates that longer-duration treatments and higher PH₃ concentrations improves fruit quality compared with controls, mainly by reducing rots. These treatments fully controlled thrips but provided only partial control of mould mites.

KEYWORDS:

• ECO2FUME
• phosphine fumigation
• market access
• postharvest
• mould mite
• greenhouse thrips

Acknowledgements

The authors gratefully acknowledge the assistance of Martin Napper, AVANZA Ltd for sourcing the fruit and Justin Tumambing, CYTEC Australia Pty Ltd, NSW, Australia, for training and assistance with PH₃ fumigations (ECO2FUME®) at our PFR fumigation facility. We also thank Mari Nakano and Zhongyi Liu for technical assistance in insect mortality assessments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was funded by New Zealand Avocado with support from Sustainable Food and Fibre Futures Funding.