Yes, I think you have a fungus problem
Coryneum beijerinckii
Was pretty sure. Thank you for the confirmation Matrix. I’ll research my options.
Could this be bacterial spot or is it definatley shot hole fungus? Should I be treating with anything now or is my best bet to treat with copper in the dormant season? Thanks again.
in winter it can be treated with copper, but copper is a product to prevent.
if you want to cure your trees now you have to use a “healing” fungicide, unknown to those who are for sale in your country.
Thank you great info I’ll do some research.
Wildscaper,
I was surprised to see any disease foliage issues like this in a greenhouse. Generally greenhouse foliage looks completely disease free.
Are you using any form of overhead irrigation?
I think you are in TX? Fungal shothole is more prevalent in Western states, whereas bac. spot is more prevalent in the Eastern U.S. I think in this instance TX would be more like a Western state.
If it’s fungal shothole Davis recommends mostly management of the disease during the dormant season (i.e. copper). However captan is labeled for coryneum blight during the growing season only.
Thank you so much for the info. No over head irrigation at all. I too was very surprised to get this. I may have an explanation though. My trees are in containers and are outdoors all fall and winter. I wonder if the trees could have picked up the blight then. Also a few of the trees were newly purchased this year so maybe one of those had the infection already from last year and it spread to the other trees this year? Just a theory. At any rate I’ll look into captan to treat now and then apply copper a few times during dormancy. Does this sound like a good course of action?
I agree, those leaf issues started outdoors. Next spring you need to treat the trees the same as trees spending full time outdoors.
Treating now won’t likely make any difference. New leaves aren’t being infected indoors and those yellow leaves are beyond help. Still in your shoes I’d likely spray once now just to sleep easy.
I was thinking of treating now only because I was afraid of the older leaves infecting the new growth is that logical? And yes it may make for better sleep!
In your greenhouse I don’t think there will be any reinfection. I’ve had no leaf issues with stone fruit in mine. There is no rain and no dew therefore no bacterial or fungal infections of the leaves.
I agree, any treatment won’t have any curative activity on the infected leaves. I have no experience with a greenhouse or fungal shot hole, so I will defer to Fruitnut about the likelihood of new leaf infection at this point.
Captan is labeled for coryneum from pink through cover sprays, but I suspect most benefit is achieved through the earlier sprays. That’s generally the way it goes with most fungal infections.
Ok I will gladly defer to y’alls expertiece here and wait till dormant season unless I see new growth getting hit. Any favorite brand or formulation of copper that I should look for?