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Author Topic: F2 citrange winter hardiness trial  (Read 21194 times)

kumin

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Re: F2 citrange winter hardiness trial
« Reply #225 on: January 31, 2020, 04:12:53 PM »
The low percentage of survivors was mitigated by the initial 21,000 seeds, which should have produced 3,000 zygotic seedlings. .5 % of those gives approximately 15 (actually 12) healthy, vigorous survivors. This winter has been quite mild to this point and unless there's a dramatic change, the number of survivors would have been much higher. I was fortunate to have a severe winter, as it eliminated many less hardy plants.

I am satisfied that last winter's survivors were not a fluke, as the hardiest show no damage this winter.

I believe any Flying dragon seedlings not showing contorted branching should be zygotic, as nucellar seedlings should be all be contorted. Some of the contorted seedlings may also by zygotic.

Unfortunately, I am not aware of any more northerly Poncirus growers. However, although there has been dieback on mature trees on occasion, the last truly deadly winter was in 1994. I'm certain Poncirus can survive further north, but that dieback is likely increasingly severe as one goes north. I'm skeptical of survival in north-central Pennsylvania as well as central New York state. Coastal New Jersey/New York/New England may fare better.

If I'm successful in getting the segentranges to flower and fruit, I would expect a modest to high percentage of their zygotic seedlings to be hardy in zone 6b. I fervently wish I had embarked on this project sooner and more seriously.

Here a 2 photos of Conestoga # 11 segentrange top grafted on Poncirus out of doors. There's no damage on the # 11, but there's minor damage on late growing Poncirus twigs on the rootstock. These scions look very promising at present, but February and March are still remaining on the calendar.




« Last Edit: February 01, 2020, 04:22:08 PM by kumin »

tesilvers

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Re: F2 citrange winter hardiness trial
« Reply #226 on: February 03, 2020, 10:08:09 AM »
Those grafts are looking good!

I agree about the Flying Dragon seedlings - all straight ones and some of the contorted ones should be zygotic. Speaking of which... here's one of the more vigorous obviously zygotic seedlings of Flying Dragon.


kumin

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Re: F2 citrange winter hardiness trial
« Reply #227 on: March 02, 2020, 07:25:35 AM »
Barring an unusual change in weather, there will be little to no cold damage this winter. Even the Meyer lemon seedling shows no real damage. Fortunately, the previous winter eliminated the tender seedlings. The protective structure was successful, but not really needed. The lowest temperature to this point has been +10 degrees F., not really zone 6b weather. This is 22 degrees F. warmer than last winter's low.

Meyer lemon unharmed, and unlikely to be harmed.


2 updated photos of Conestoga #11 scions grafted on Poncirus showing no damage.






hardyvermont

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Re: F2 citrange winter hardiness trial
« Reply #228 on: March 02, 2020, 11:57:57 AM »
Barring an unusual change in weather, there will be little to no cold damage this winter. Even the Meyer lemon seedling shows no real damage. Fortunately, the previous winter eliminated the tender seedlings. The protective structure was successful, but not really needed. The lowest temperature to this point has been +10 degrees F., not really zone 6b weather. This is 22 degrees F. warmer than last winter's low.

Meyer lemon unharmed, and unlikely to be harmed.


Was the Meyer Lemon protected? 
Several of my seedlings that are hardier than Meyer have shown damage, and the low here was 20 F





[/quote]

kumin

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Re: F2 citrange winter hardiness trial
« Reply #229 on: March 02, 2020, 12:18:27 PM »
The structure these trees are in is unheated. However, the combination of white overwintering poly plus the 3 layers of frost cloth likely provided 8-10 degrees of protection in addition to 100% shielding from wind. If this winter had been a repeat of last winter, I don't think the Meyer would have stood a chance at survival, let alone being undamaged. I have no plans for the Meyer, simply threw it inside on a lark. None of my plants suffered much damage either. The frost cloth sheets were frozen together, even this morning. There was also shallow frozen soil around the interior of the structure.

This is great in regards to getting closer to flowering/fruiting, but doesn't help in further defining hardiness. If we'd had these temperatures last winter, I believe there may have been thousands of survivors.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #230 on: March 27, 2020, 03:27:27 PM »
An interesting phenomenon I noticed today: when the Poncirus+ as well as the citrange hybrids have a mixture of deciduous and evergreen twigs/branches, the deciduous twigs fairly consistently push buds before the leafed twigs do. It stands to reason that a leafed twig has less urgency to replace the previous season's foliage.

Poncirus+ exhibiting both deciduous and retained foliage branches.


Millet

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Re: F2 citrange winter hardiness trial
« Reply #231 on: March 27, 2020, 10:32:47 PM »
From looking at your soil in the picture, it looks like you have a tractor and a disk.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #232 on: March 27, 2020, 11:45:51 PM »
Thanks millet, actually being under a stay-in- place Covid 19 order by the governor gave me an opportunity to get some physical exercise. The winter weeds needed to go before getting out of hand. So the tools used were a narrow trenching shovel and a hoe. Although I have often thought about having a tractor, I can't really justify owning one on a 1 acre property.


kumin

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Re: F2 citrange winter hardiness trial
« Reply #233 on: March 29, 2020, 07:30:35 PM »
The original growing beds used for the 2018/2019 winter trial were not maintained, nor monitored since May 2019. Today, I walked over the unkempt beds and saw a surprising number of plants that grew from low stem/root positions last summer and have survived this very mild winter with little damage. A few of the plants are nearly as large as  the plants I sheltered and pampered for a year. I plan on letting them undisturbed an additional year, then evaluate any that emerge undamaged from the upcoming winter. These plants have now survived 2 winters unprotected in zone 6b, although the past one was very mild.

The first photo shows a plant with minimal thorniness, especially in the top half of the stem.













« Last Edit: March 30, 2020, 02:57:48 PM by kumin »

mikkel

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Re: F2 citrange winter hardiness trial
« Reply #234 on: March 30, 2020, 10:41:50 AM »
those plants might be already hardy enough in zone 7.
probably yes but do you think they are zygotic seedlings?
« Last Edit: March 30, 2020, 10:43:31 AM by mikkel »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #235 on: March 30, 2020, 12:21:35 PM »
mikkel, some of these are zygotic. Photos #2, 3, and 5 are zygotic for certain. However, some shoots sprouted belatedly from underground roots.Some of these may be F1 C-35 seedlings despite my statements to the contrary last year. I'm sure no C-35 plants had surviving above ground stems. When I made my selections in the spring of 2019, I only selected plants with above ground living stems.

There are indeed likely plants within my collection that could survive zone 7. I have a nephew living 200 miles (321 kilometers) south of my location (still a bit north of member eyeckr) . After I graft additional clones of my selections, I plan on taking a number of plants to his location for zone 7b trial. Of course fruit qualities, or lack thereof, remain to be revealed.
« Last Edit: March 30, 2020, 03:02:14 PM by kumin »

lebmung

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Re: F2 citrange winter hardiness trial
« Reply #236 on: March 30, 2020, 05:17:17 PM »
From so many seedlings there are some tetraploids.  I wonder how you can identify them.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #237 on: March 30, 2020, 06:53:52 PM »
Having grown thousands of Poncirus seedlings, I saw stocky, thicker leafed plants I felt pretty certain were tetraploids. I really didn't observe any citranges that I felt were tetraploids, but with so great a range of unique segregating characteristics, it's difficult to discern.
« Last Edit: March 30, 2020, 09:21:31 PM by kumin »

lebmung

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Re: F2 citrange winter hardiness trial
« Reply #238 on: March 31, 2020, 03:37:12 PM »
yes they have thicker leaves, here it's a image that might help. The percentage is very low, maybe one in 1000 but you have many seedlings, maybe you can find one.


kumin

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Re: F2 citrange winter hardiness trial
« Reply #239 on: March 31, 2020, 04:48:16 PM »
Thanks lebmung, I will keep an eye open for tetraploids as I survey the plants. Is your interest related to the production of triploids, or for a different reason?

kumin

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Re: F2 citrange winter hardiness trial
« Reply #240 on: March 31, 2020, 05:13:27 PM »
Delete
« Last Edit: March 31, 2020, 05:16:46 PM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #241 on: March 31, 2020, 05:15:26 PM »
Here are pictures of potential tetraploids:








lebmung

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Re: F2 citrange winter hardiness trial
« Reply #242 on: March 31, 2020, 07:55:56 PM »
Thanks lebmung, I will keep an eye open for tetraploids as I survey the plants. Is your interest related to the production of triploids, or for a different reason?

Yes a triploid with a yuzu would be nice.

Some in those pictures have round leaves but lack the short petiole.
Look for plants with very short petiole and smaller, they don't grow so vigorous at the this stage.
« Last Edit: March 31, 2020, 07:59:05 PM by lebmung »

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #243 on: April 01, 2020, 03:32:11 AM »
Small seeds  even in partially zygotic varieties are enriched in spontaneous triploids
Best regards,
                       Ilya

kumin

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Re: F2 citrange winter hardiness trial
« Reply #244 on: May 01, 2020, 01:07:13 PM »
Conestoga 011 came through winter unscathed. I haven't seen damage on any of the numerous grafted trees of this selection. This is possibly the hardiest specimen I have, with the exception of Poncirus. If only I could "fast forward" the next several years. Grafted on outdoor Poncirus.


Conestoga 058 monofoliate selection, not as hardy as 011 and 010, but likely as hardy as TaiTri, or possible a bit hardier. Original plant in coldframe. Presently flushing.


Conestoga 010, hardiness close to Conestoga 011. Hardier than TaiTri and 5* citrumelo. End of season high graft onto outdoor Poncirus.

« Last Edit: May 01, 2020, 01:09:02 PM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #245 on: May 03, 2020, 06:33:51 AM »
The monofoliate Conestoga #058 appears to appeal to both aphids and especially slugs. There seems to be a preference for this clone over the others. The leaf scent is more pleasant on this plant also. Hopefully this may be an indication of fruit flavors?
Small Conestoga 058 graftlings, one with signs of leaf feeding damage.



« Last Edit: May 03, 2020, 04:09:26 PM by kumin »

mikkel

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Re: F2 citrange winter hardiness trial
« Reply #246 on: May 03, 2020, 05:52:56 PM »
To have a monofoliate cold hardy hybrid is an interesting progress

kumin

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Re: F2 citrange winter hardiness trial
« Reply #247 on: May 03, 2020, 06:09:25 PM »
This clone is not the hardiest of the original survivors, but fairly close. During limited winter testing it compared favorably with TaiTri, perhaps a bit hardier. More extensive testing should help determine it's true hardiness.

#058 is likely the plant in the back, with #067 being the plant in the front.


#058 is one of these two monofoliate specimens. This photo was taken before numbers were assigned to the survivors. There is a short length of original seedling stem, but less than the several hardier selections.

« Last Edit: May 03, 2020, 06:25:52 PM by kumin »

poncirsguy

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Re: F2 citrange winter hardiness trial
« Reply #248 on: May 03, 2020, 08:23:14 PM »
How do you determine if an next generation is hardier.  If it is and you go 1 degree 2 cold then its dead and of no use.  Do you have a refrigerator/freezer that you can test 1 degree at a time for precision.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #249 on: May 03, 2020, 08:49:41 PM »
I see cold damage as incremental. Best case: no discernable damage. Worst case: total failure as you indicated. Between the two extremes there should be a gradient from hardy to non-hardy. Poncirus at my location falls into such a gradient. Once past the first year seedling stage, almost never totally killed, usually unharmed, but occasionally damaged with subsequent regrowth and recovery. I would expect the hardiest selections to follow a similar, but lower scale.

In regards to testing, I would rely on natural, empirical conditions rather than relying on artificially produced testing. Firstly, I don't have such facilities, secondly, cold damage occurrs on a number of fronts, ranging from late Autumn freezes to absolute low temperature in midwinter, to duration of various levels of damaging cold, continuing to late dehydration caused by sun and wind during periods of frozen soil. Finally, Spring freezes can injure tender, new growth.


All of these conditions may be reproducible, but not within my capability. I suggest that selecting an exact point on the thermometer for making or breaking the test for hardiness doesn't weigh in on  the large number of variables.
« Last Edit: May 04, 2020, 04:09:32 AM by kumin »

 

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