Myrtle rust attacks plants of the Myrtacae family — rata, pohutukawa, manuka, kanuka, swamp maire and ramarama – as well as exotic myrtles like eucalypts, feijoa and guava. Sparse rusty-red spots soon erupt into yellow pustules, leaving plants looking like they’ve been dusted with turmeric powder.
Myrtle rust stifles flower and seed development so badly that the Ministry for Primary Industries (MPI) fears we could lose whole tracts of myrtle species, altering the composition and ecology of myrtle-dominant forests. The consequences for nectar feeders like tui and kaka, which rely on trees like pohutukawa and rata to get into breeding condition, become clear.
Spores of myrtle rust are carried on the wind, but trampers can also spread the disease if they touch an infected plant. So, if you see what you suspect might be myrtle rust, leave it well alone, but do take a clear photograph of it. GPS the location if you can, or at least be sure you could lead a technician back there if necessary. Then give MPI a call on 0800 80 99 66.
Winter is planting season for many native revegetation projects, but MPI asks that you don’t plant any myrtle species in the New Plymouth, Waitara, Kerikeri or Te Kuiti areas.
– Dave Hansford