Potato spindle tuber viroid
Potato spindle tuber viroid (PSTVd) can reduce the yields of potato by 65% and tomatoes 40 to 50%.
PSTVd has been reported around the world, including in Australia. In Victoria, it was detected only in tomatoes and then eradicated.
A viroid is like a virus but has a simpler structure.
Symptoms of PSTVd
In potato, infection with PSTVd often causes smaller and elongated potatoes. While above the ground, the potato plant can become upright and extended with smaller leaves.
In tomato plants, symptoms can include stunting and discolouration of the leaves that initially turn yellow and then become red or purple (Figure 1). Tomato fruit production also stops with severe infections.
Management of PSTVd
The best way to avoid disease is by using planting material free of PSTVd. For example:
- only get seed potatoes from suppliers with tubers certified free of PSTVd
- source tomato seeds from a reliable supplier
PSTVd can be found in the sap of plants and is easily spread by contact. Appropriate sanitisation and precautions are needed to prevent the transmission of PSTVd by machinery, tools and people that have been in contact with infected plants.
A consideration during an incursion, is that other plants can be a reservoir and sources of PSTVd. These include:
- garden plants such as Brugmansia suaveolens (white angel's trumpet)
- weeds such as Solanum nigrum (black nightshade)
- commercially important plants such as Capsicum annuum (capsicum), Solanum melongena (eggplant) and Persea americana (avocado)
Those in the latter group are often not as badly affected as potato by PSTVd. These hosts can be symptomless.
Reporting an unusual plant pest or disease
Report any unusual plant pest or disease immediately using our online reporting system or by calling the Exotic Plant Pest Hotline on 1800 084 881. Early reporting increases the chance of effective control and eradication.
Please take multiple good quality photos of the pests or damage to include in your report where possible, as this is essential for rapid pest and disease diagnosis and response.
Your report will be responded to by an experienced staff member who may seek more information about the detection and explain next steps.
Report onlinePhoto credits
Figure 1 courtesy of the Department of Agriculture and Food, Western Australia.
References
CABI, 2020. Potato spindle tuber viroid (spindle tuber of potato). In: Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/isc.
Plant Health Australia, 2015. Fact sheet: potato spindle tuber viroid [Web page], retrieved from https://www.planthealthaustralia.com.au/wp-content/uploads/2015/08/Potato-spindle-tuber-viroid-FS.pdf on 13 May 2020.