New apple tree with leaf problems

[tomsav]

Hi everyone, apologies for what might be idiot questions but I'm new to apple tree growing and could do with some advice...

I planted a young tree a couple of months ago, it's now about three-and-a-half feet tall. It's an Apple Family Tree from Thompson and Morgan (Apple 'Family Apple Tree' - Apple & Pear Trees - Thompson & Morgan) and ever since it has had various sick-looking leaves. See the pics below.

The tree is three apple varieties; much of the ill-looking leaves are on the Golden Delicious part.

Some leaves are pock-marked, others are curled up, others have a white powdery growth on the underside. Can anyone advise if the tree is sick, or am I being an overcautious new parent??




Thanks for your help!

[Paulottie]

Goodevening and welcome to the vine.

no question idiotic here you know....well almost.

Would like to say I knew problem but I don't.

Might be scab but I can't tell. One of them looks like some sort of leafminer. I think the overall health is
okay.... from last pic.

I guess don't worry...I am sure someone can help if I'm wrong.

[FB.]

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Picture 1 (top left): scab.

Picture 2 (top right): probably scab, but if not scab it is not of much concern.

Picture 3 (middle left): probably powdery mildew (the white furry coating under the leaf) and a brown scab spot adjacent to the yellowish patch.

Picture 4 (bottom left): leaf miner.

Picture 5 (bottom right): probably powdery mildew.

In pictures 3 and 5, although powdery mildew is the probable diagnosis, the pictures aren't quite clear enough, and it might just be the natural hairs on the underside of the leaf.

Golden Delicious, being quite a commonly-grown variety, and like most other well-known varieties, can be rather prone to scab (and sometimes mildew or canker) in some parts of the country. My Goldie always ends up a tattered, reddish-brown mess due to scab and I'm not in an area that typically has wet summers (this year excepted!).

Having said that: a few spots and marks on the leaves is unavoidable if you want to remian spray-free - and even if you spray, you'll probably still get the odd spot on a leaf.
The amount of leaf damage is probably 5%. An otherwise healthy tree can cope with 25% of its leaf area damaged (i.e. a quarter of every leaf damaged, or complete destruction of one-in-four leaves).

So generally your trees problems are of no major consequence.

I would, however, recommend removing the leaves which have mildew, as this is an especially troublesome problem in my part of the country which can eventually kill entire branches by incorporating itself into the shoots as they grow and weakening them. It does not spread through the sap, or move along the woody parts unlike canker, which will.

[FB.]

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Here's a pic of my Goldie, with very browned leaves (much of which was scab) taken in summer 2010 (we didn't get abnormal amounts of rain here that summer)

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[tomsav]

Thanks for the detailed reply, FB.
I'll take some clearer pics of what may be the powerery mildew tomorrow and will post them (best to make sure before I start hacking the leaves off!)
Thanks again.
Tom

[FB.]

Here are a few pictures of powdery mildew:

1. Three (four if you include the weak one) apple seedlings (just a few months old) which have become infected.

2. One large and the small seedling are now dead, and only two seedlings remain - and they are in severe decline due to heavy mildew attack. They eventually died from overwhelming powdery mildew.

3. Close-up of a seedling, showing the lowest leaves (the first to open) with relatively light white powdery coating (the mildew took a few weeks to find the seedling), then leaves in the middle of the stem have died as the mildew quickly spread up the growing shoot. The topmost leaves are infected and likely to die within a few weeks after this picture being taken. The seedling died.

[FB.]

So all the books which shrug-off powdery mildew as a minor disease should come round my area for a mooch around, and see just what a killer it can be.
These are seedlings - and seedlings are generally considered to be very tough and vigorous; too vigorous to be used as rootstocks nowadays.