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Mystery Disease ???

Posted: Thu Jun 26, 2014 3:59 pm
by rickg
I'm trying to find out what this is on my apple trees.
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At first I thought it was cicada damage but it's early for annual cicadas and I don't hear or see any. Then I was told that it was fireblight, but I don't have the classic shepherd hook on the young shoots. Then someone said it was scab but I can't find anything on the internet concerning scab that looks like this. Does anyone else have an idea as to what this is??? The trees are Antonovka seedlings 6 to 8 years old that I'm top-working over to assorted varieties. I've also found it on a pear tree. Help!!!

Rick

Re: Mystery Disease ???

Posted: Fri Jun 27, 2014 9:27 am
by dmtaylor
Looks like freeze-thaw damage. Are the cracks confined to the south or southwestern portion of the bark? The theory goes that if very wet weather is followed very quickly by very cold freezing weather, the tree might not have time to adjust its water content, resulting in bursting of the bark, since water expands a lot when freezing.

Re: Mystery Disease ???

Posted: Fri Jul 11, 2014 2:54 am
by OrangePippin-Richard
I agree with dmtaylor. This is not an insect or fungal infection.