Myrtle rust is an unwanted organism under the Biosecurity Act 1993 and it is an offence to deliberately spread it. It is not mandatory to report a myrtle rust infection to MPI.

NZPPI has developed a comprehensive management programme, including a Myrtle Rust Climate Tool which can be used to optimise the timing of fungicide applications and non-chemical management methods. The protocols and tools can be accessed on the NZPPI website via the Resources menu: NZPPI Plant Disease Management Platform - NZPPI

Plant Pass is a voluntary Biosecurity Certification Scheme which includes a specific module for plant producers growing Myrtaceae species. It supplements the Core Standard of Plant Pass (PPBS, the Scheme), and describes specific measures to manage the risk of a nursery becoming infested by or spreading the pathogen myrtle rust.  

There are several things plant producers can do to help minimise the severity of rust in the nursery.  Young myrtaceae plants are especially vulnerable to myrtle rust as spores infect soft, new growth of leaves and shoots. So timing when plants are trimmed or potted, to avoid a flush of new growth during the susceptible period (summer) can help.

Spores need approximately 6 hours of leaf wetness to germinate and infect young plant tissues. Timing irrigation to come on early in the day, to wash any spores off the leaves from the night before and giving leaves have a chance to dry off during the day will help. Placing susceptible species in the windiest part of the nursery also helps plants to shed leaf wetness.