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Author Topic: F2 citrange winter hardiness trial  (Read 22773 times)

usirius

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Re: F2 citrange winter hardiness trial
« Reply #200 on: October 22, 2019, 02:58:22 PM »
Please find my impressions and oictures from the first HRS899 seedling fruit I opened and tasted today in another thread here in the Forum:

http://tropicalfruitforum.com/index.php?topic=30863.msg369960#msg369960
„May your choices reflect your hopes, not your fears.“ N. Mandela

kumin

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Re: F2 citrange winter hardiness trial
« Reply #201 on: November 15, 2019, 12:16:13 PM »
In preparation for winter, the open ground planted trees, as well as the potted trees have been enclosed in a cold frame shelter. This may not be needed in an average winter, but it provides a means for emergency protection if a 50 year Arctic cold event should occur. The very lowest temperature seen in this area in my lifetime was -24 deg F (-31.1 C) in January 1994. Such a temperature would wipe out all the pots and destroy all the other plants, at least to ground level.

This structure was hastily constructed as  we experienced a low temperature of 18 degrees (-7.77 C) earlier this week. The original plan was to cover in early December, but plans were changed due to weather forecasts. The plants easily coped with the 18 degrees. The plan is to protect the stems in order to  get flowering and fruiting in a few years.

There are no intentions of heating the structure, but in the event of temperatures lower than -10 deg F.(-23.3 C) it would be an option.








« Last Edit: November 27, 2019, 06:25:17 PM by kumin »

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #202 on: November 15, 2019, 01:49:50 PM »
With first frost coming two out of five of my cicitrumelo seedlings (5star citrumelo pollinated by FD) are preparing to shed its leaves.

Best regards,
                       Ilya

kumin

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Re: F2 citrange winter hardiness trial
« Reply #203 on: November 15, 2019, 02:00:15 PM »
Ilya, early dropping of leaves is a good indicator of winter preparedness. My area had warm weather until recently leaving some plants unprepared. The hardiest plants from last winter appear to again be the best prepared at this point.
« Last Edit: November 24, 2019, 06:49:10 PM by kumin »

Zitrusgaertner

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Re: F2 citrange winter hardiness trial
« Reply #204 on: November 18, 2019, 04:09:05 AM »
Ilya, does your Citrumelo 5* drop leaves in late autumn? Mine keeps ist leaves over winter. Some of cause die but about 50% survive in a merely mild winter. Trifolis, which is said to be F2 and less hardy, changes colour and drops some leaves. Most hardy PT hybrids seem to drop leaves but also keeps some. Also leaves on my yuzu turn yellow and drop off. Not sure how many of them will get lost.

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #205 on: November 18, 2019, 08:54:04 AM »
Robert,
5 star is never dropping leaves here in the autumn. Some of them are dropped during the winter while still green. This happens during Arctic episodes with strong winds.
Interestingly, like you see in the cross above, this trait is recovered in 2 out of 5 back crossed seedlings.
One of them has leaves with  poncirus-like odor and taste , while those of another have only faint bitterness and smell like a true citrus.
Best regards,
                       Ilya

Zitrusgaertner

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Re: F2 citrange winter hardiness trial
« Reply #206 on: November 19, 2019, 03:48:47 AM »
so there is one that drops leaves and might be of better quality?

Zitrusgaertner

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Re: F2 citrange winter hardiness trial
« Reply #207 on: November 19, 2019, 03:52:36 AM »

This is my 852 with fruits. Pictures taken last Saturday.
« Last Edit: November 19, 2019, 03:54:23 AM by Zitrusgaertner »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #208 on: November 20, 2019, 03:32:34 PM »
Nice looking fruit. After they're ripe, new photos would be welcome 😁.

Zitrusgaertner

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Re: F2 citrange winter hardiness trial
« Reply #209 on: November 21, 2019, 06:22:17 AM »
They may look nice but they won't taste nice  ;)

mikkel

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Re: F2 citrange winter hardiness trial
« Reply #210 on: November 25, 2019, 12:01:05 PM »
Kumin, How old were your plants when you planted them out? They seem to be very large for 1 year old plants?

kumin

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Re: F2 citrange winter hardiness trial
« Reply #211 on: November 25, 2019, 12:15:40 PM »
The seeds were planted April 12 2018. They were germinated in a heated bed. Subsequently the seedlings were field transplanted in early June of 2018. They were 9- 10 months old at the time of maximum exposure to the winter low temperatures.
Some of these plants were grafted onto Poncirus rootstock during the summer, which resulted in some larger plants, but some of the original plants have good size. The soil planted trees are the originals, the potted plants are potted Poncirus rootstock, or F2 back-up Segentranges grafted on Poncirus rootstock.
To answer your question more directly, these plants will be 2 years old in April, 2020.
« Last Edit: November 27, 2019, 08:02:42 PM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #212 on: November 25, 2019, 12:54:59 PM »
A number of seedlings and grafted specimens as they show leaves preparing to abscise for winter.

A seedling of either Meyer lemon, or Moro blood orange showing good tolerance to this point. No expectations of winter survival.



Ichangquat 6-7-2 seedling showing shoot damage - not deciduous (not expected to be).



TaiTri seedling not showing much damage, partially deciduous at this point.



5* Citrumelo showing minor tip damage, not deciduous at this point.



Segentrange # 58 monofoliate, not deciduous, showing a bit of tip damage (off photo). Original plant (in soil).



Segentrange #21 deciduous, showing little damage. On Poncirus rootstock.



Segentrange #001 deciduous (not last year), no damage. On Poncirus rootstock.



Segentrange # 010 deciduous, no damage. On Poncirus rootstock.



Segentrange # 011 deciduous, no damage, possibly
the hardiest specimen. On Poncirus rootstock.

« Last Edit: November 27, 2019, 01:26:59 PM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #213 on: December 18, 2019, 02:42:46 PM »
Multiple layers of frost cover have been placed over the plants . Neither the white overwintering plastic, nor the frost cover have a dramatic effect used on their own. The exterior poly cover shields the interior from the wind allowing the frost cover to become more effective. Supposedly using the two in conjunction can have an 8-10 degree benefit. This is the first time I will be using either of them. In the event of unseasonably mild weather, I will remove the frost cover.

This protection may be a bit of pampering, but I'm eager to get to flowering and fruiting as quickly as possible.


« Last Edit: December 19, 2019, 08:48:20 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #214 on: January 24, 2020, 08:23:55 AM »
Our winter has been relatively mild to this point, with numerous lows at 15 to 17 degrees F. One of the segentranges has developed purplish leaf coloration. If I'm very lucky this may be inherited from the Ruby blood orange grandparent? A blood colored segentrange would be interesting, but certainly unproven at this point.
The coloration is clearly a response to cold temperatures, but there's no certainty that any fruit would develop similar coloration.




Florian

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Re: F2 citrange winter hardiness trial
« Reply #215 on: January 24, 2020, 08:43:56 AM »
Exciting nonetheless. Keep up the good work!

tesilvers

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Re: F2 citrange winter hardiness trial
« Reply #216 on: January 24, 2020, 09:54:00 AM »
Kumin, I love what you're doing. About ten years ago, I had planned to do the same (only not with C-35 specifically), but only got so far as to call the seed vendor. I was supposed to call back in a few months when it would be seed harvest time, but other things of life distracted me. In February, I plan to follow through this time and do a smaller scale version of your project. In the meantime though, I've been growing yearly batches of US 852 seedlings (thanks to Stan McKenzie) and most years all of the seedlings (nucellar and zygotic) have winterkilled. Occasionally a few have survived a winter, only to get killed in the next winter. Last winter only one seedling survived, so I recently dug it up and brought it indoors out of fear. I'm hoping to high graft a piece onto trifoliate later to see if it is reliably hardy here. We're zone 6b but just about on the border of 7a.



In all the years I've dabbled in container growing citrus and growing Poncirus in the ground, 2019 was the first time I'd ever tried a hand pollination. I used pollen from an old Poncirus (I think was Rubidoux) on 3 flowers of a potted calamondin. So far, I've got two definite hybrid seedlings.

Keep up the great work with your F2 C-35's!!!
Tom

kumin

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Re: F2 citrange winter hardiness trial
« Reply #217 on: January 24, 2020, 10:07:36 AM »
tesilvers, interesting, in which county are you located? I'm only 40 miles north of Harford/Cecil counties.
If I were to repeat the winter trial, I would increase the number of seeds initially sown, but would pre-select the seedlings, field planting only vigorous, certain zygotic specimens.
Glad to hear from a colleague.

Walt

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Re: F2 citrange winter hardiness trial
« Reply #218 on: January 24, 2020, 11:56:12 AM »
I'm glad to hear reports on progress, and serious attempts to progress in winter hardiness in citrus.
 haven't put out any F2 plants this year.  Rather I plan to graft lots of F2 seedlings on Ponciris in spring, in hopes they will survive next winter.
And I plan to grow many F2 plants to fruiting, even if the part grafted and grown outside doesn't survive next winter.  I want to know how sugar, acid, and resin segregate.  And I want to learn to test for survival at various temperatures.
If some  segentranges were reliable in zone 7, some of their seedlings might give a much better percentage of zone 6 survivers.

tesilvers

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Re: F2 citrange winter hardiness trial
« Reply #219 on: January 25, 2020, 06:09:39 AM »
Hi Kumin,
We're in Washington county Maryland, near Harpers Ferry West Virginia. We hardly ever have any cold damage on Poncirus, but I haven't been able to keep any F1 types alive outdoors here.
I was a member of the Indoor Citrus and Rare Fruit Society back in the 80's, and my membership transferred to California Rare Fruit Growers afterwards, so I recognized Major Collins name when you mentioned him. The trifoliate I used on my potted calamondin is a descendant from the indoor citrus society seed bank offerings.
I'll keep your advice in mind when I order seed soon, but I have to operate within my Christmas money budget.   ;)
I hadn't mentioned it but I'm also trying to simultaneously improve trifoliate without citrus interbreeding. So far, I've got about a dozen zygotic seedlings of Flying Dragon lined out to see how much variation the fruit will show. I plan on extending that row as I germinate more seedlings. I've got another small batch germinating right now. Nucellar seedlings will become rootstocks; zygotic seedlings will get added to the row.
Thanks for inspiring the rest of us dreamers.
Tom

kumin

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Re: F2 citrange winter hardiness trial
« Reply #220 on: January 25, 2020, 06:52:47 AM »
tesilvers, in the future I may have an improved flavor Poncirus, known as Poncirus+ selection available. This selection is supposedly zygotic and the fruits should have less resin and bitterness. My plants are juvenile seedlings at present, but should eventually produce large quantities of seeds. I have 7 of these young trees.

My F2 citranges approach Poncirus in cold hardiness, I don't know exactly how close at this point. The segentranges are 2 years old vs the Poncirus+ which are only 1 year old.
An option I have, would be to cross the Poncirus+ and the segentranges, hoping to combine almost all of Poncirus hardiness with reduced off flavors and perhaps some blood orange influence.
« Last Edit: January 25, 2020, 07:07:36 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #221 on: January 26, 2020, 12:02:28 PM »
tesilvers,
In the cold hardiness testing I've done over the years, there was greater variation of cold hardiness present in the F2 generation than found in the F1 generation. That being said, there was both increased and deceased hardiness in the F2 population.
While there were individuals with increased hardiness, they were few in number, approximately .5 %(vigorous).

tesilvers

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Re: F2 citrange winter hardiness trial
« Reply #222 on: January 27, 2020, 07:52:07 PM »
That would be reasonable to expect - to get a range of hardiness in the [true] F2. Were the approximately 0.5% with increased hardiness that you mentioned, out of the original 20,000 or out of the 15% zygotic F2?

Glad Poncirus+ is in the US. I was under the impression that it was only available in Europe. Less resin and bitterness sounds like a move in the right direction. Although, I haven't really noticed bitterness, just extreme sour (which is okay to me). But, the gumminess is definitely off putting.

I saw that you've been noticing differences in habit of dormancy. I had one Flying Dragon seedling that went dormant earlier than three siblings. I thought these four were all nucellar but maybe the one was actually a contorted zygotic seedling. My thought when I saw this one, was that it could give offspring with better (earlier and/or stronger) dormancy. Any thoughts on this matter from your experiences with the varied F2?
Thanks, Tom


kumin

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Re: F2 citrange winter hardiness trial
« Reply #223 on: January 27, 2020, 08:45:44 PM »
tesilvers,
The .5 % is on the 15% zygotic seedlings. In zone 7 the percentage should be higher. It's a bit difficult to get solid numbers since there isn't necessarily a sharp cutoff between normal and dwarf plants, as there are also plants with intermediate vigor. There are a few cold hardy Citrus breeders with juvenile Poncirus+, but I'm unaware of any mature fruiting trees in the US. Flying Dragon is reported to have higher percentages of zygotic seedlings than some other Poncirus selections.

Clearly, one of your trees has a different coloration than the other 3. Even the remaining 3 might not all be nucellar seedlings. Careful observation might reveal subtle variation in foliage, thorns, flowering, and fruits.
« Last Edit: January 27, 2020, 08:51:19 PM by kumin »

tesilvers

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Re: F2 citrange winter hardiness trial
« Reply #224 on: January 31, 2020, 03:34:04 PM »
0.5% of the 15% zygotic - not an easy road by any means! :)
But I'm still gonna give it a go too. I just ordered 2 quarts of Sacaton which (contrary to early reports of being completely nucellar) has been reported to have 40-50% zygotic seedlings. I'm excited to finally get to try this out. Wish me luck!

I've never counted the numbers of "off-type" seedlings but I've definitely seen a relatively high percentage of obviously zygotic seedlings in Flying Dragon batches. I've got about a dozen straight-stemmed and straight-thorned ones planted in a row to evaluate for fruit variation whenever they mature. They came from an isolated mother tree, so I'm assuming they're from selfing which might explain their slow growth rate (- inbreeding depression maybe???). I'd like to try some intentional pollination this coming season using Rubidoux pollen on Flying Dragon to see if the percentage of off-type seedlings increases and to see if the vigor would be noticeably better.

Concerning the early dormant Flying Dragon seedling above... as a side project, I'd like to see how far North I can get a pure trifoliate to survive. Do you know of anyone growing trifoliate unprotected in zone 5b? I have a location in North Central Pennsylvania that I can test plant some seedlings and thought I might try the early dormant one there.

 

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