Sycamore tar spot, where is it?

[daltontrees]

The chat is much more interesting than the subject of this thread!

Today I saw a sycamore (I was surveying it for the Council) with NO tar spot on it. I've never before in my life seen such a thing. And you can be sure ht Council doesn't clear up the leaves in this park every winter or the bit of waste ground next door right under the canopy. Maybe I've got R. acerinum growing on my brain and it's affecting my vision. NOT seeing spots before my eyes, as it were.

[born2trot]

Yep , bang on , hardly a jot here ..

[Treecreeper1961]

Not wanting to de-rail but did anyone notice the very early loss of leaves, mostly on lower branches, on sycamores this summer? Especially on river banks. Any ideas on the cause?

[born2trot]

Not wanting to de-rail but did anyone notice the very early loss of leaves, mostly on lower branches, on sycamores this summer? Especially on river banks. Any ideas on the cause?

 

There was a thread on it a while back , cant remember the poster but i think it was down to prolonged dampness and the lower leaves suffering the most .

[daltontrees]

I've had a look at 'Diseases of Trees and Shrubs' (Sinclair et al). The most relevant bit I can see is "During autumn and spring apotheca develop in stromata on fallen leaves that remain moist. Apotheca ripen during spring, split the surface of the stroma open, and eject sticky ascospores as much as 1mm into teh air. Some spores alight on young maple leaves, thereby starting a new annual cycle." Also mentioned is "Conspicuous outbreaks of tar spots are infrequent except in moist sheltered locations favourable for winter survival of the causal fungi".

1 mm is not a lot. It would need a bit of wind eddies around trees to get the spores up to the new leaves. My amateur theory for the lack of spots up here is that it was so hot (yes, hot!) in late march when the leaves were flushing that the leaf litter from the previous year was bone dry, preventing apotheca ripening and spore ejection. The subsequent 6 months of horizontal rain must have helped the trees too.

I wonder, did the areas where there is lots of tar spot have bizzarely dry weather around bud break? I guess Aberdeeen would have been hot like Glasgow at the time.

[Brett]

I've had a look at 'Diseases of Trees and Shrubs' (Sinclair et al). The most relevant bit I can see is "During autumn and spring apotheca develop in stromata on fallen leaves that remain moist. Apotheca ripen during spring, split the surface of the stroma open, and eject sticky ascospores as much as 1mm into teh air. Some spores alight on young maple leaves, thereby starting a new annual cycle." Also mentioned is "Conspicuous outbreaks of tar spots are infrequent except in moist sheltered locations favourable for winter survival of the causal fungi".

1 mm is not a lot. It would need a bit of wind eddies around trees to get the spores up to the new leaves. My amateur theory for the lack of spots up here is that it was so hot (yes, hot!) in late march when the leaves were flushing that the leaf litter from the previous year was bone dry, preventing apotheca ripening and spore ejection. The subsequent 6 months of horizontal rain must have helped the trees too.

I wonder, did the areas where there is lots of tar spot have bizzarely dry weather around bud break? I guess Aberdeeen would have been hot like Glasgow at the time.

 

I've taken a few sycamore down recently from St Andrews up to Blairgowrie, all have spotting.

[born2trot]

I've had a look at 'Diseases of Trees and Shrubs' (Sinclair et al). The most relevant bit I can see is "During autumn and spring apotheca develop in stromata on fallen leaves that remain moist. Apotheca ripen during spring, split the surface of the stroma open, and eject sticky ascospores as much as 1mm into teh air. Some spores alight on young maple leaves, thereby starting a new annual cycle." Also mentioned is "Conspicuous outbreaks of tar spots are infrequent except in moist sheltered locations favourable for winter survival of the causal fungi".

1 mm is not a lot. It would need a bit of wind eddies around trees to get the spores up to the new leaves. My amateur theory for the lack of spots up here is that it was so hot (yes, hot!) in late march when the leaves were flushing that the leaf litter from the previous year was bone dry, preventing apotheca ripening and spore ejection. The subsequent 6 months of horizontal rain must have helped the trees too.

I wonder, did the areas where there is lots of tar spot have bizzarely dry weather around bud break? I guess Aberdeeen would have been hot like Glasgow at the time.

Aberdeen hot lol!!! Not hot but the north east has very little rain fall , one of the driest areas in the uk i believe , combined with it being windy alot .

Checked a clients sycamores today with a fellow arbtalker .. no tarspot .

Even checked a churchyard en route to the ice rink .. again nothing .

[kieran connell]

seen lots of tar spot in sefton, merseyside area!

[kieran connell]

i thought london planes where very slow to come in to leaf this year! could it be to do with the previous winter being milder?

[daltontrees]

Brett's comments about tar spot in fife and Angus fairly spoils my amateur theory but then born2trot confirms Aberdeen is same as around Glasgow. Southeast, Wales, Merseyside and Bucks spotty.

I was down in London between Christmas and New Year last year and the Planes were still partly in leaf along Pall Mall. See photo.

Mild aint the word.

There aren't enough up here for me to have noticed if they came out early.