The Northern Territory government is working with cucurbit growers to create a long-term plan for managing Cucumber Green Mottle Mosaic Virus (CGMMV).
Quarantine measures were lifted from infested properties early last year, and since then production across the Territory has returned to a significant capacity. But it is recognised that the virus cannot be eradicated completely, and the Department of Primary Industries and Resources is working on a management plan, with funding from this month's budget and Horticulture Innovation Australia.
"To date, since February 2016, there has been no CGMMV infected fruit intercepted at market," a spokesperson from DPIR said. "This is good news as it indicates that the implementation of on-farm biosecurity measures appears to be working."
DPIR says there has been research conducted internationally on CGMMV, but gaps in knowledge still exist. This new project will address key research areas, identified by industry stakeholders.
"This includes identifying new crops that can serve as an alternative crop, should a property become infested with CGMMV," the spokesperson said. "It will also identify weed species that are CGMMV hosts and whether CGMMV can be transmitted from the weed seeds, new and current in-field diagnostic tools and kits will be evaluated to determine their suitability to detect the virus in a rapid and accurate manner."
The virus was first detected in 2014 in the Territory, before it was also discovered Queensland and Western Australia, prompting a national emergency response. Out of 160 farms producing cucurbits across the NT, 25 were infected, mostly large scale watermelon farms. The virus can also be carried by cucumbers, zucchini, pumpkin, squash, and other varieties of melons.
The ideal outcome is to create management strategies for living with CGMMV for those infested properties. The department says preliminary research has primarily showed a reduction of CGMMV particles in soil over time, but it needs to be looked at more closely.
"The longevity of the virus in soils and bee hives will provide critical data that is not readily available," DPIR said. "Then finally communications and extension materials (need to be given) to stakeholders detailing research findings, grower meetings, surveys to gauge how the industry is fairing."
Symptoms of the virus include leaf distortion, with blistering and bubbling, while the fruit itself can be spotted and internally discoloured through rotting. But the effects can differ between plant species.
It can be spread in many ways and may remain viable for an extended period in plant debris and soil, or on vehicles, equipment and tools. DPIR cannot stress enough the importance of on-farm biosecurity awareness, saying infested properties should implement methods to prevent further spread within their properties.
"Purchase clean seeds that have been tested with the higher seed numbers (9400 seeds) from a reputable seed company and seed imports are certified as CGMMV free," the department recommends. "(It's important to) manage weed population around production areas. The motto is 'Come clean, leave clean and stay clean'".
CGMMV does not infect humans.
For more information:
Department of Primary Industries and Resources
Phone: +618 8999 2006