Author Topic: Big freezes and variety selection  (Read 949 times)

tedburn

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Big freezes and variety selection
« on: December 23, 2022, 04:39:51 AM »
Yesterday looking for more information to the big freeze 1962 and 1963 concerning the conditiond freeze time and freeze deepest temperatures and surviving varieties, but didn' t find useful information. Does anybody know sources with useful concrete datas ?
By the way I found interesting information to the freeze
1894  ;)
https://floridahistoryblog.com/the-great-freezes-1894-95-and-the-collapse-of-the-florida-orange-industry-7442e5d75337

1rainman

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Re: Big freezes and variety selection
« Reply #1 on: December 23, 2022, 12:06:56 PM »
Generally grapefruit are the best survivors of cold in terms of edible fruit. Pommelos are slightly more cold hardy than grapefruit. Tangerines are more cold hardy than oranges this tangelos do well (half grapefruit half tangerine). I'm in south west Florida and before greening killed everything juice oranges didn't do well here (Valencia and such) though navels did. North Florida tangelos like honeybell or grapefruit do well. Meyer lemon but not regular lemons.

They can be grown with effort but the citrus industry really grows stuff that isn't cold tolerant enough for their zone then freaks out every time a freeze comes. Now days all the citrus is wiped out here due to greening other than some wild tolerant varieties. But a grapefruit or pommelos will grow pretty much anywhere in Florida though I guess the panhandle might be a bit stressful on them since that is the coldest part of Florida.

tedburn

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Re: Big freezes and variety selection
« Reply #2 on: December 24, 2022, 01:35:43 AM »
1rainman, thanks for your post, very interesting, how every location had it s own difficulties. We don't have HLB (and don' t get it hopefully) but we have in z7 sometimes hard freezes, so that in ground planted varieties have to be very hardy, and early fruit ripening as e.g. satsumas.
Up to now we only still know one single variety which has these abilities, the Chimäre Prag, a genetical mix of Poncirus and Satsuma. I have it in ground the 3. Winter but still no fruits yet, first flower this summer. But this variety is susceptible at my place to freeze and wintersun otherwise it gets bark cracks, needs protection.
What I didn' t know and didn ' t test in my place, that Pomelo is hardier than Grapefruit.

bussone

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Re: Big freezes and variety selection
« Reply #3 on: December 24, 2022, 09:56:57 AM »
1rainman, thanks for your post, very interesting, how every location had it s own difficulties. We don't have HLB (and don' t get it hopefully) but we have in z7 sometimes hard freezes, so that in ground planted varieties have to be very hardy, and early fruit ripening as e.g. satsumas.

Zone 7 may not be immune from greening. At least, there are enough cold-tolerant plants than get HLB and enough cold-tolerant plants that can host psyllids that it could march north.

tedburn

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Re: Big freezes and variety selection
« Reply #4 on: December 24, 2022, 06:09:38 PM »
Yes perhaps HLB can move north, but hope this will hopefully not happen, in zone 7 we still have a lot to do
to handle the winter freezes  ::).
So the intention of my post originally was to get more information about the freezes 1962 and what resulted from thesee, which deepest temperatures at which locations and which varieties survived ? Does anyone more about that, or has someone links to articles about the freeze and the survivors.


Sylvain

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Re: Big freezes and variety selection
« Reply #5 on: December 26, 2022, 10:52:23 AM »
tedburn> We don't have HLB (and don' t get it hopefully)

bussone> Zone 7 may not be immune from greening. At least, there are enough cold-tolerant plants than get HLB and enough cold-tolerant plants that can host psyllids that it could march north.

Bussone, Mühlacker is in Europe (Germany).  ;)



Galatians522

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Re: Big freezes and variety selection
« Reply #6 on: December 26, 2022, 09:02:14 PM »
I don't have a link, but one thing that I can tell you is that trees under drought like conditions with very low sap flow survive cold far better. I remember hearing the following story on several occations which makes that piint quite well.

There was a citrus nursery that was going out of business and donated all its remaining stock to a local church. After the stock was donated the water was turned off and things got very dry. A terrible freeze followed which wiped out all the nursery stock in the state and many mature trees. All the nursery stock that is except for the trees in the nursery where the water had been turned off...they all survived and were sold for top dollar.

Maybe you could gain a little hardiness by drying your tree out a little more to induce a deeper dormancy?

tedburn

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Re: Big freezes and variety selection
« Reply #7 on: December 27, 2022, 02:50:39 PM »
Galatians, thanks for your comments.
I think adequate watering is also important for further cold resistance.
I didn' t found an article to the survivor citrus cultivars of the big freezes, what was my intention, but I found an other as I think interesting article.
https://blogs.ifas.ufl.edu/washingtonco/2014/01/11/satsuma-protection-in-cold-weather-extremes/