Model predicts appearance of plant disease in Christchurch

According to the New Zealand Herald, officials are taking action after myrtle rust was found on a mature hedge in residential Christchurch, marking a new southern point for the likely establishment of the disease.

Lincoln University Associate Professor Eirian Jones, of the Department of Pest Management and Conservation, said the find was predicted by the risk modelling carried out by former Lincoln student Dr Hossein Khandan, as part of his PhD studies.

His work was published in 2019 by journal Plant Pathology, in a paper called “Projecting the suitability of global and local habitats for myrtle rust (Austropuccinia psidii) using model consensus”, a joint project with the Bio-Protection Research Centre and Plant and Food Research.

Dr Khandan is now Senior Advisor-Biosecurity Science and Risk Assessment at the Ministry for Primary Industries.

Myrtle rust is considered a serious risk to indigenous plants, including pōhutukawa, mānuka, ramarama, rōhutu, and rātā and to biodiversity in New Zealand.

The research identified hotspots with a high probability of establishment of the disease.

A favourable annual temperature range was found to be the variable with the most influence in predicting areas for myrtle rust to establish.

The model projection indicated that the Northland and Auckland areas in the North Island (except the central highlands) were highly suitable for myrtle rust establishment.

The rest of the North Island and small areas of the South Island around Nelson, Blenheim and Christchurch were projected as suitable.

Associate Professor Jones said the news of the spread was concerning, but showed the model had real-world application and could be useful in the battle to eradicate or control the pest by identifying areas for more intensive monitoring.

Find out more about the Master of Pest Management programme here.

Image: Myrtle rust, Ministry of Primary Industries