What is Candidatus Liberibacter solanacearum?
The Tomato potato psyllid can carry a bacterium called Candidatus Liberibacter solanacearum (CLso) which is associated with the potato disease 'zebra chip'.
Psyllids carrying the bacterium not only cause damage to plants through feeding, they can also infect plants with the bacterium, causing disease. The bacterium is transmitted by the psyllid feeding on infected plants. It only takes 1-2 hours of feeding on the sap for the psyllid to infect a plant.
Tomato potato psyllid has been found in Western Australia, mainly in the Perth metropolitan area and surrounds, and some regional areas in the South of the State. Currently there has been no detection of the CLso bacterium in Australia or Western Australia.
Symptoms of Candidatus Liberibacter solanacearum
Symptoms of the CLso bacterium on potatoes, tomatoes, capsicum and chilli may look similar to other plant conditions, so growers are urged to be vigilant for the following symptoms:
Symptoms in tomatoes
Plants may become stunted or abnormally elongated. Foliage symptoms include leaf curling and yellowing. Fruit development is uneven. Tomatoes may be misshapen, or no fruit is produced or there is an over-production of small, non-commercial grade fruit. Symptoms vary in severity between cultivars.
Symptoms in capsicums and chillies
Parts of the plant may die back. Foliage symptoms include leaves becoming misshapen, pale green or yellow with spiky tips and leaf stalks appear stunted. Flowers may drop prematurely. Symptoms vary in severity between cultivars.
Symptoms in potatoes
Potato plants may have shortened internodes and aerial tubers may develop in the leaf nodes. Potato tops are likely to be smaller than normal. The foliage turns yellow and may have a burnt or purplish appearance. Stems may die completely but regrowth from the base may occur. Tubers from affected plants may have small stalked tubers protruding from the main tuber (called ‘chaining’) and when cut may show internal browning of the vascular ring or brownish streaks along the medullary rays.
What is being done
The Department of Agriculture and Food is working with industry to manage TPP in Western Australia following the national decision that it cannot be eradicated.
Following the detection of the psyllid, there has been extensive testing of plant material for CLso. Further testing will focus on psyllid populations in the Perth control zone to give greater confidence that CLso is not present.
What can you do
Check and report.
Everyone in Western Australia who grows potato, tomato, eggplant, chilli, tamarillo or sweet potato should check their plants for the TPP.
If you see suspect signs of psyllid or CLso:
- send a photo to the Department of Agriculture and Food, WA via the MyPestGuide Reporter app available from the Google Play or Apple store.
- email photos with your name, address and mobile number to email@example.com; or
- call the Pest and Disease Information Service on 1800 084 881.
All suspect signs of CLso and TPP will be investigated.