Symptoms of Botryosphaeria Canker on Pistachios
Botryosphaeria Canker ---how to see the symptoms on pistachio. Themis Michailides is a plant pathologist and lecture in the Department of Plant Pathology, UC Davis
“And these symptoms will develop on the leaves and the fruit when we have rains in the spring. So, we need sufficient rain to see the symptoms of small lesions on the Leaves, and also round lesions on the fruit. And some of these lesions then, we'll expand to cause blight of the fruit,” Michailides explained.
“Now, when we have a normal year, some rains, and even when there is Botryosphaeria inoculum in the field, you will not see the symptoms, but infections will occur and those are the latent infections that do not cause any symptoms, but they are established well in the epicarp, which is the outer layer of the pistachio hull,” said Michailides.
Now when we talk about lesions on fruit, do not confuse this with the fungi. He says
Other things resemble Botryosphaeria, but it not the disease.
“We have the citrus flat mite that can cause very similar lesions. And certain herbicides can also cause similar symptoms,” he said. If you take your knife and scrape these lesions, they are very superficial. The Botryosphaeria lesions, go into the epicarp. You can scrape it with a knife, and you can see underneath the skin. It’s black and goes into that area.
To learn more about Botryosphaeria on pistachios search through the UCIPM website.