What is brown spot?
Brown spot of jujube is caused by the fungal pathogen Nothophoma quercina. This pathogen has recently been detected in a jujube orchard in Western Australia for the first time and is suspected to have been present in Australia since 2014. Little is known about N. quercina and it has only been reported as a pathogen in the last decade
Symptoms of brown spot
The fungus appears to infect leaves and fruit, and woody tissue. On the leaves, the fungus causes spots with a tan centre and black to brown margins, and then a yellow halo. In the centre of the spots are black fruiting bodies called pycnidia.
On the fruit, there are brown to black spots with small pycnidia. The fruit starts to shrivel.
Report the disease if you find it
If you suspect brown spot, send a photo to the Department of Primary of Industries and Regional Development, via the MyPestGuide Reporter app available from the Google Play or the App Store or email photos with your name, address and mobile number to firstname.lastname@example.org. Alternatively, call the Pest and Disease Information Service (PaDIS) on 1800 084 881.
To date this fungus has been reported on pistachio (Pistachia vera), olive (Olea europaea), Chinese quince (Chaenomeles sinensis) and on a perennial herb (Phellodendron amurense) in the Rutaceae family. In California and Arizona USA, the pathogen attacks fruit clusters near harvest time.
Control of Nothophoma quercina
At present there are no registered fungicides. In the USA, trials are being done to evaluate the use of fungicides to control Nothophoma infections in pistachios.
Practice sound crop hygiene/biosecurity practices to prevent the entry, establishment and spread of pests and diseases.
- Check the plants you purchase are free of pests and disease and don’t bring infected plants into your property.
- Regularly monitor your plants for any unfamiliar pests or diseases.
- Report any suspect pests or diseases to the Department of Primary of Industries and Regional Development’s Pest and Disease Information Service (PaDIS) by email at email@example.com or freecall 1800 084 881.
- The Pest and Disease Information Service (PaDIS) provides advisory and identification services on animal and plant pests, weeds and diseases that impact Western Australia’s agriculture and food industries.
- Report suspect pests or diseases via the MyPestGuide Reporter app.