Is this fungal?

Afternoon just wondered if anyone could identify what’s wrong with my chestnut saplings? Fungal, sun or something else? One of them has lost its leaves completely but is still nice and bendy. TIA

   

It could be fungal but looks like water stress to me

Oh yes I think that’s what it is...they are in pots and I’ve not been watering them enough! Thanks boss!

It could be horse chestnut leaf blotch....we have two large horse chestnuts so I've read up lots on it.
I also have the mite it's worth making sure all leaves are cleaned up and keep them healthy. A feed - tomato feed is fine, would help.

Horse chestnuts seem a bit sickly in their early years, round here at any rate. We have one grown from a conker that is doing OK now but a farmer planted 5 at the end of the road one has died and 2 others are struggling.

I believe the horse chestnut is on the list of those in danger of dying out. The leaves dying now so it doesn't produce enough conkers.

Leaf miner kill off the leaves in early summer on mine. Mine are too big to feed - but I try to pick up all the leaves in the winter to lessen leaf miner - we don't get a huge conker harvest for the size of the tree.

Years ago park keepers would clean up all the leaves. That doesnt seem to happen anymore so all the miners can overwinter in the leaf matter.

We have one that’s at least 20 years old. Flowers last year, no concerts. Flowers this year so we will see.
One of these has lost its leaves completely but still seems healthy, if that makes any sense.

We have a conker tree at the top of the garden that started off life 6" tall in a 4" pot left by the previous owners, we planted it in 1985, 8ts now massive and although it has the black leaf blotches it still produces loads of conkers, no sign of dying out here. Not a lot of help to you though Jay.

We have one that’s at least 20 years old. Flowers last year, no concerts. Flowers this year so we will see.
One of these has lost its leaves completely but still seems healthy, if that makes any sense.

If you have it in a pot it's difficult to keep it watered so it may be just that. Regular water and feeding should make a huge difference.'

We have two....this is the good one, but does get the brown leaves. So I pick up all the leaves which is hard work.

   

We have another one that is the same size around the other side of the house. We have had to get a tree surgeon to cut branches out. It is going hollow now. I have a friend that is an arborist and he can check the tree health on the  inside -amazing kit.  He pierces the trunk with what looks like a long needle /super long piece of metal that he drills into the trunk ( it's super thin) this produces a document giving the density of the wood inside etc. Sadly mine has deteriorated year on year. We can't afford to cut it down at the moment but it will be coming down soon. We had remedial work done on it last year. We have taken out lots of the old dangerous wood out over the years.