Apple tree disease - please help identify problem

[Gemmalaveen]

I bought a container grown apple tree from my local garden centre in April this year and planted it straight away. The tree was full of blossom and produced plenty of fruit - I had to thin out about 75% of the fruit because there was so much.

It's a CORONET miniature apple tree grown on dwarf rootstock M27 - the variety is Elstar. This was a bit of an impulse purchase because I have been designing a garden from scratch - I have 5 other cordon apple trees trained along the fence which I got from a reputable fruit nursery... they are all healthy.

The CORONET tree was perfectly fine until a few weeks ago when the leaves started going blotchy and some of them are now starting to shrivel. The tree looks unhealthy now as if it wants to keel over. There are no marks on the fruit - only leaves affected. I am guessing it is probably a mix of rain and then extreme heat.

Can this tree be saved? What is wrong?

I am not keen on using chemicals because I have loads of bees and ladybirds in my garden.

[FB.]

It looks like scab - a fungal disease which appears a couple of weeks after infection is initiated due to the leaf surfaces being wet for several hours.

Symptoms can't be cured once they appear.
Unless it happens every year, it is unlikely to kill the tree, but will reduce its vigour.

I would see what happens next year.

Out of interest - what other varieties do you have?

[Llamas]

Oof. Nasty. Haven't got any useful advice but I can offer sympathy. I've had a similiar dissapointment with a nectarine tree which has contracted a ugly case of peach-leaf curl. Theres nothing for me to do now but try to avoid looking at the poor little thing until it passes. Hope your tree gets better!

[Gemmalaveen]

Thanks FB & Llamas. I didn't think it was scab because I don't see marks on the fruit but they probably just haven't appeared yet After doing research I thought it might be nectrotic leaf blotch or something along those lines - but I don't know much about fruit trees.

Should I remove all diseased leaves now along with all the fruit to give the tree a chance to recharge its batteries? Would it be better to just dig it up and write it off?

The other varieties I have are:

Red Windsor
Bountiful (cooking)
Joybells
Discovery
Empire

[FB.]

Thanks FB & Llamas. I didn't think it was scab because I don't see marks on the fruit but they probably just haven't appeared yet After doing research I thought it might be nectrotic leaf blotch or something along those lines - but I don't know much about fruit trees.

Should I remove all diseased leaves now along with all the fruit to give the tree a chance to recharge its batteries? Would it be better to just dig it up and write it off?

The other varieties I have are:

Red Windsor
Bountiful (cooking)
Joybells
Discovery
Empire

Your "other" varieties are known for having some resistance (and Empire not being a typical UK variety is also likely to not suffer too badly due to lack of adapted diseases).
I would leave the damaged leaves. They are still partially functional and gathering some light. Reoving them now might be even more of a shock to the tree. Chances are that it'll drop the damaged leaves in a few weeks time anyway - trees often get rid of damaged leaves and fruits naturally.
I'd give the tree a little extra fertiliser than its companions in order to keep its vigour up.

I would not dig it up. I find that in some years one variety takes a beating from pests or diseases, but the next year it is often fine, with a different variety taking a battering. That's the beauty of having a broad selection; there's usually one or two that actually like the conditions, but not all will give their best every year.

It's possible that the problem isn't scab - sometimes other less-common fungal diseases can look similar.

Scab on leaves doesn't always mean scab on fruits. Leaves and fruits have different tolerances of infection and also the susceptibility depends on the age of the leaf or fruit, in addition to the toughness (i.e. physical resistance to penetration by the germ tube <"taproot"> of a fungal spore). Some varieties also have different antifungal substances in leaves or fruits. Some also have coatings on the fruits - Spartan has a hydrophobic coating although it can be washed off with extreme rainfall, while some varieties have russeting (russet is scar tissue due to death of the fruit skin) which may block fungal attack.

So in summary:
Give the tree a little more fertiliser than its companions - including a light sprinkling now.
Don't remove the tree; next year it may be your star performer if the weather changes!
Only if it fails to perform several years in a row should you consider getting rid of it or re-grafting it.

[Gemmalaveen]

FB, thank you very much for such an insightful reply.

I noticed yesterday that some of the fruits are looking a bit haggered and that some of the leaves have fallen all on their own. I will leave the tree to figure things out for itself.

Better luck next year!