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Date: 17 Oct 2008
Source: Weekly Times [edited]
<http://www.weeklytimesnow.com.au/article/2008/10/17/16911_horticulture.html>

Potato cyst nematode found in Gippsland, Victoria, Australia

A 20km (12.4mi) quarantine zone in Thorpdale's potato region has been declared following the discovery of potato cyst nematode (PCN).
The discovery, made during routine crop surveys required to meet standards for seed potato certification, could have a devastating effect on the industry. Department of Primary Industries (DPI) scientists identified PCN in soil samples taken from the affected property this week. Additional samples have been sent to an interstate laboratory for further confirmation.

DPI Principal Plant Standards Policy Officer David Beardsell said that DPI was meeting with potato industry authorities and growers today [17 Oct 008]. "A team has been set up by DPI to manage the response to the detection which is likely to include an intensive soil surveillance program, to establish the PCN status of other properties in the district," he said. "This will be in addition to the ongoing soil testing required by certified seed growers."

Dr Beardsell said trade restrictions would apply to areas where PCN was detected including a 20 km exclusion zone. No plant material or equipment from the zone can be moved interstate. "Unfortunately this detection has serious implications," he said. "It will affect market access for both seed and fresh potatoes grown in the area around the detection site."

The discovery comes just 6 months after a plant protection zone was declared in Gippsland and after 16 years of testing found no evidence of PCN. Mr Beardsell said Thorpdale supplied up to 30 percent of Australia's certified seed potatoes, so there could also be repercussions for seed supply around the country next season. "Joint efforts by DPI and industry to effectively manage this case of PCN will minimise both the risk of spreading this disease further and the trade implications," he said.

Dr Beardsell said the industry and DPI had effectively managed previous cases of PCN in the Gippsland area. He said it was not known how the disease entered the property. "PCN can be transferred on machinery or product but we also know it can remain dormant in soil for up to 20 years," he said.

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[Both golden (_Globodera rostochiensis_) and pale (_G. pallida_) cyst nematodes cause serious crop losses in potato. They can also infect other solanaceous crops and weeds. Symptoms on potato are stunting, yellowing and wilting of leaves, as well as a reduced root system.
Damage to the crop varies but can be a complete crop failure. The pathogens survive in soil in the absence of a host as cysts containing viable eggs for up to 20 years. Spread occurs via infected soil, water, wind, or on plant material. It takes about 6-7 years from introduction into a potato paddock before numbers of the nematodes reach a detectable level. Disease management includes exclusion, quarantine, and crop rotation with non-host species. For more information on these nematodes please see previous ProMED-mail report no. 20080714.2138.

The report above does not state which of the 2 species has been detected. However, _G. rostochiensis_ has been found in the region previously and it is therefore more likely that this is the pathogen referred to.

Maps
Australia:
<http://www.ga.gov.au/image_cache/GA4073.jpg>
Victoria:
<http://www.ozhorizons.com.au/vic/map.htm>
<http://healthmap.org/promed?g=2146767&v=-36.283,144.183,6>
Worldwide distribution of golden nematode (September 2006):
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_rostochiensis/HETDRO_map.htm>
Worldwide distribution of pale cyst nematode (September 2006):
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDPA_map.htm>

Pictures
Symptoms of golden nematode on potato plants:
<http://www.dpi.vic.gov.au/CA25677D007DC87D/LUbyDesc/Ag0572a/$File/Ag0572a.jpg>
and
<http://www.nysaes.cornell.edu/ent/bcconf/talks/images/brodie2.gif>
Golden and pale cyst nematodes:
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDSP_images.htm>

Links
Information on _G. rostochiensis_:
<http://www.dpi.vic.gov.au/dpi/nreninf.nsf/childdocs/-71E8091F577D52D24A2568B30004F3B2-07E8C65C31CFC12CCA256BC800029303-4C9C6833948D4DF54A256DEA00274836-386AFCFE1CD9F10ECA256BCF000BBFE4?open>
Data sheets on both potato cyst nematodes:
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/HETDSP_ds.pdf>  and <http://www.inspection.gc.ca/english/plaveg/pestrava/gloros/tech/glorose.shtml>
Diagnostic techniques for both nematodes:
<http://www.eppo.org/QUARANTINE/nematodes/Globodera_pallida/pm7-40(1)%20HETDSP%20web.pdf>.
- Mod.DHA]