Psyllid Yellows Zebra Chip - Identification and Control

Psyllid yellows causes stunting and yellowing of the growing shoots of affected plants. In potatoes it also causes zebra chip which is an effect on the potato tubors such that when cooked the potatoes have dark stripes in the interior flesh.

Psyllid yellows disease is caused by the bacterium Liberibacter solanacearum. The bacterium is spread from plant to plant by the psyllid sap sucking insect pest. The only way currently available of controlling the disease is to control the psyllid insects.

How to solve the problem

Control of psyllid yellows is achieved through control of psyllid insects.

Avoid bringing infected plants into your garden. During winter remove all plants that could be host to infection. Inspect susceptible plants regularly for signs of infection or infestation with psyllids. Remove and dispose of any plants that show symptoms of infection.

Use Organic Insect Control with Pyrethrum to crop plants, paying particular attention to the underside of leaves where adults and nymphs live. Follow product instructions for use on crops carefully.

Inspect plants regularly for the presence of psyllids, so that treatments can be applied while numbers are low.

Remove, bag and disposes of as much leaf litter in the area as possible as this may harbour eggs.
Apply Organic Insect Control to plants as protection or on finding any psyllids. Concentrate on the underside of the leaves, where most of the psyllid adults and nymphs live.
More than one application may be required (3-4 days apart) to kill all the nymphs.
Best applied late in the day.
It is important to control psyllids on young plants as they are most vulnerable to psyllid yellows. Older plants are still vulnerable to infection by the bacterium, but any fruit that is set will still be harvestable.

Did you know?

The scientific name of the tomato/potato psyllid is - Bactericera cockerelli
The name of the bacterium that the psyllids spread and causes disease in tomatoes, potatoes, capsicums and tamarillos is Liberibacter solanacearum