North American Fruit Explorers mailing list at ibiblio

["D Stubbs" <dsmndel@gmail.com>]

This is an important subject to cold climate growers, but so far I haven't found anything that relates why one apple frost damages at 27F and another at 15F.  Makes me wonder if I should get a brix refractometer ( any apple growers out there find them handy?) , but the apples I am thinking of seemed to have a similar sweetness. Does anyone know the mechanism that regulates frost damage - Cell structure? Sugar Starch Content?  Parentage? Ripeness?  
Del,  2b/3a  n. Mn

On Tue, Nov 4, 2008 at 11:53 PM, Steve <sdw12986@aol.com> wrote:

Lucky Pittman inspired this comment when he asked what temperature would
damage his late apples. This isn't intended to be another answer for him
but more a story about what I just experienced.

Honeygold is about the latest ripening apple I dare to grow here. Some
years, they aren't very good because the season wasn't long/warm enough.
 I mentioned some months ago about how I didn't spray a fungicide this
year due to rain, wind, or both just about every day in the early part
of the summer. The Honeygolds suffered greatly from this and were badly
spotted and scarred by scab. (The high speed hail storm in June didn't
help their looks either.) I wanted to thin them heavily to get rid of
the most damaged fruit but they were so bad that I lost interest and
never did thin them properly.

I picked the best of them before we had a hard frost but left most of
them on the tree, thinking I would pick and discard the rest. (I still
hope to do that.)

I walked out there today and noticed that there were still some decent
Honeygolds up in the tree. I tasted one and it was good so I picked a
dozen more of the better ones and took them inside. I have eaten two
more today. If someone had asked me the same question about how cold can
they go without damage, I would have answered upper to maybe mid 20s.

Here's the point of all this. We had a prediction last weekend of 10 or
11 degrees for the low. Today I checked my recording thermometer, which
is wired to a different apple tree near the Honeygold and my yard went
down to 15 degrees Saturday night. I do believe the texture of the
apples I picked today is slightly different but they are still good. If
you tell me they would now not store as well, I would believe it. I'm
just surprised they are still very edible after 15 degrees. Any comments?

Steve in the Adirondacks (Zone 4a on the map, zone 3 by the thermometer)

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