Leaf-miner damage or leaf blotch?

[RobUk]

Hey I'm new here :)

 

I've just got a quick question. I'm from the UK and I have a horse chestnut tree in the front of my garden. It's well established and probably 100+ years old if I was to guess. 

 

Anyway, this year I've noticed the leaves are looking really bad. I can't figure out whether it is leaf-miner damage or leaf blotch. The damage seems to be on probably 90% of all the leaves on the tree but some of it is is much worse than others. 

 

I'll attach a picture and hopefully someone might be able to help me determine what the issue is: 

 

Thank you to anyone who can help me.

[openspaceman]

miner Cameraria ohridella

[Gary Prentice]

12 hours ago, RobUk said:

I can't figure out whether it is leaf-miner damage or leaf blotch.

Not much that you do whichever pathogen it is, apart from good hygiene, removing fallen leaves to help re-infection the following year.

Officially the threat is a reduction in the photosynthesizing surfaces, but bare in mind that this becomes a greater stressor when it occurs year after year. Reducing the trees energy production and reserves.

It wouldn't hurt to improve the trees rooting environment, to allow it to capitalize on the soils available moisture, air and nutrients. So a good mulch using a well rotted wood-chip etc, covering as much of the root area as the surroundings allow.

 

Both of the pathogens currently affecting horse chestnuts seem to come and go, as you said good years with little infection, bad years with lots. A few years ago it was a bad year and Manchester council marked up loads of highway trees for removal. Some didn't get done and now (well last years) the remainders where thriving. So over reacting or rushing to act probably isn't for the best.