So I’ve been noticing large groups of rust fungus (Gymnosporangium nelsonii I believe) infected saskatoons in the past two years (southern Alberta). (though, I only began taking notice of plants in the past two years so I’m not sure about fluctuation).
But the amount of infections I am seeing does not seem, normal. I see more infected plants than healthy ones, and its the whole plant, almost all berries and leaves have this fungus on them. I was wondering if any professional environmentalist/plant epidemiologists had any ideas on where to start investigating this? I think starting a project on here might be a good start but I’m not sure if it should be just documenting infected saskatoons and if that would skew any data.
I tried contacting a restoration ecologist from Edmonton and she told me to try contacting the city landscapers and they straight up didn’t respond (not that I’d really know what to ask them I guess).
I’m not an expert on plant diseases and might be qualified at all to give a good answer, but here’s my opinion:
If indeed *Gymnosporangium nelsonii then this is a native fungus to N America that has a relationship with the Saskatoons (Amelanchier sp., I presume). I’ve observed rusts on serviceberries in the NE and there seem to be some years where they’re very common, some where they’re not. Many organisms have cyclical cycles. I don’t think native pathogens, especially “rusts” tend to permanently negatively impact populations because they’ve been at this song and dance a long time. A higher frequency of infection might also be a symptom of some other stressor, like drought or pollution than anything else.
There’s also the possibility that you’re noticing them more frequently. However, observation is important. I think it’s perfectly fine and appropriate to make a project for this phenomenon and upload observations of the rust.
Usually by the time infection is apparent there’s no real treatment. And like I said before, this might not be abnormal at all. Unless I knew for certain I wouldn’t be reaching out to landscapers that may spray harmful substances in futile.