I have three mountain ash trees covered with fruit. All of the fruit are also covered with something that appears to be a rust. I can’t find any diseases specifically affecting M.A. fruit. I try to figure out if this is just because of a very wet and cool weather in June, or it is something I can expect every year. For me, to keep mountain ash trees is only for the fall look. If they not going to produce, I may need to replace them with something else. The trees are too high to spray properly, if there is a spray…
Mountain ash are susceptible to fireblight. Is that what yours have?
1 Like
im surrounded with m.t ash and it’s been very wet here as well and i never seen anything like that on mine. if you dont like them you can graft them over to pears like i did. they take well on them.
1 Like
It doesn’t look like fire blight to me, there are spikes on the fruit, brown to orange colored. They go inside the fruit as well. If it resembles anything, it may be apple scab, but slightly…
Couple more photos:
1 Like
Looks like a gall to me…
2 Likes
These are not flowers, these are fruit. And leaves are not affected…
Sorbus is a pomefruit… has been hybridized with pear, so not that distantly related… while I don’t recall specifically seeing mention of rust on members of that genus, I would not be surprised if some or all were susceptible to one or more strains of the Gymnosporangium fungus.
It’s a bad year for rust on several species here, this year… rust pretty well took the mayhaw crop in its entirety, serviceberries escaped significant damage, Centennial crab fruits are badly hit, as are the fruits of several of the pears whose blossoms/fruits escaped the spring freezes - particularly Shinko & Niitaka. Worst rust year I’ve had - on all species - ever.
1 Like
I think you nailed it. Picture of hawthorn infected looks exactly like my sorbus fruit.
And I think I do have ceder near by. Previous owners planed a line of trees on the border with neighbors - couple evergreens I didn’t identify yet, possibly ceder, three mountain ash and hawthorn maple. Very strange choice for privacy - none of them other than evergreens planted in the far corner have any branches low enough for privacy. I like mountain ash, so I guess I will have to remove evergreens.
1 Like
The junipers (Eastern redcedar) don’t even have to be all that close to your fruit trees… fungal spores can travel at least 2 miles on the wind… there are probably not many places in the eastern USA where there are no ‘cedars’ within that distance.
So, removal of my cedars is futile. Will at least I get Sorbus fruit once in two years? Or it always will be like that if not sprayed? I like the look of Sorbus in fall, but if it will be like that every year, I will probably better remove them… Answering my own question. Last year around this time there were no fruit at all. I guess they are biennial too?
I can’t tell you… There’s no way I could eliminate all cedars within a couple hundred yards of my yard & orchard, much less within 3-5 miles.
Most years, I get at least a few mayhaws… maybe enough to make a small batch of jelly, but some years, rust takes all fruit, and may cause a few twig lesions - which I prune out as soon as I see them. Last year, many of the serviceberry fruits were rust-infected, but this year, the vast majority were ‘clean’. I’ve been seeing a large callery pear at the edge of the farm pond that gives off virtual ‘clouds’ of orange fungal spores from its tiny little fruits, but this is the first year I’ve had significant damage to fruiting pears in the orchard, or to fruits on the crabs, for that matter.
1 Like