My garden willow tree every year dies at this time due to growing a kind of black fungi on leaves
My question is this fungi the same as black fungi n
Recently killing people with low immunity due to covid-19 in India?
My wife got covid few month ago and I am worried about her safety
Thank you for contacting the Toronto Master Gardeners. I’m so sorry to hear about your wife’s illness. This is such a difficult time for so many people. I can tell you what I think is infecting your tree (although I can’t be sure without a photo), and then perhaps someone with medical training can answer your question about whether the pathogens that I think are affecting your tree are the same as the black fungus that is affecting some people with COVID.
I think your willow is infected with black canker, and also perhaps with willow scab. Together, these diseases are known as willow blight. Black canker is caused by a fungus called Glomerella miyabeana, and willow scab is caused by a fungus called Verturia saliciperda.
Black canker usually appears in July-Aug, and is the more harmful of the two fungi, often killing young leaves and twigs within a short period of time. It starts to affect the tree in the late spring when brown to black lesions appear on the leaves. Infected leaves usually shrivel and die as the fungus spreads. In the late summer – fall It creates spore masses that are pinkish in colour on the stems. It overwinters and then reawakens in the spring to disperse the spores and the cycle starts again.
Willow scab appears as spore masses that are olive brown on leaf undersides, after wet weather throughout the growing season, beginning in the spring. The severity usually lessens with warm, dry weather during the summer. It also overwinters and the cycle starts again.
These diseases also weaken the tree, making it more susceptible to insects and other diseases. It can be controlled by cleaning up all leaf litter in the fall, and by pruning out and destroying diseased branches in the late winter – early spring.
Here are a couple of links if you would like further information.
Hopefully this information will be of assistance to help you restore your willow to good health. And I hope that you will get confirmation that these pathogens are unrelated to COVID.
August 28, 2021