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Author Topic: F2 citrange winter hardiness trial  (Read 6815 times)

SoCal2warm

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Re: F2 citrange winter hardiness trial
« Reply #150 on: May 15, 2019, 08:28:52 PM »
You're probably already doing this, but I'd keep some extra cuttings in case an unusually harsh Winter kills everything outside.
The trial can move along a lot faster if spare cuttings are kept of each cultivar. One will be growing fast inside, while being simultaneously tested outside.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #151 on: May 15, 2019, 10:59:53 PM »
There are 130 Poncirus seedlings prepared and waiting for budding/grafting in June. The more desirable plants will be cloned several times. I have a geodesic frame I plan on covering during the winter with film, using water as a heat sink. There should be no need for artificial heat, provided there's adequate insulation on the north side of the structure.

This building should serve as a repository for all the clones. There are a number of seedlings (TaiTri, citrumelos, etc. from this spring's new acquisitions,these need to be cold tested to earn a place among the F2 segentranges. My intention is to have secure backup of each clone on hand.
« Last Edit: May 16, 2019, 12:02:02 AM by kumin »

lebmung

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Re: F2 citrange winter hardiness trial
« Reply #152 on: May 16, 2019, 04:32:53 PM »
There are 130 Poncirus seedlings prepared and waiting for budding/grafting in June.

how old are your seedlings?

kumin

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Re: F2 citrange winter hardiness trial
« Reply #153 on: May 16, 2019, 04:39:45 PM »
1 to 3 years old. I planted a few thousand additional seeds again this spring . I don't want to be short when I need them.
« Last Edit: May 16, 2019, 04:45:41 PM by kumin »

lebmung

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Re: F2 citrange winter hardiness trial
« Reply #154 on: May 17, 2019, 06:55:47 PM »
That is a lot of planting. Why do you sow in November when you get the seeds then you have 90% germination rate. This year I am planning also to sow 1000 seeds.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #155 on: May 17, 2019, 08:52:40 PM »
I used an easy method, in the end of March I gathered fruit that had fallen in the autumn/early winter. After soaking them in water and squeezing/manipulating the fruits, the seeds separated from the pulp. I disinfected the seeds with Sodium  hypochlorite, then rinsed them and planted immediately. Due to recent cool temperatures, seedling emergence has only been evident for the last week. Germination appears to be satisfactory.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #156 on: May 18, 2019, 12:02:25 PM »
This is a newly emerged seedling grafted to a branch mature enough to fruit. This type of graft has worked well for me. The rootstock bark is cut downward about 3.5 cm long trying not to cut into the underlying wood. The scion is prepared by selecting a thin twig and slicing off the skin of the bark on both sides, trying to not remove more of the cambium than necessary(exposing, but not removing the cambium). (It could be phrased as shaving off the epidermis on the 2 sides at the contact points.) These grafts have performed very well for me, perhaps because of the extensive cambium contact. The parafilm doesn't serve any purpose at this point other than indicating the graft location. The actual graft is lower on the stem than the parafilm.


 Waiting until these stems are mature enough to use as scions.

TaiTri seedlings growing nicely.

Citrumelos coming along well.

Surprise Magnolia grandiflora discovered growing under Poncirus. The first seedling in 22 years! 
« Last Edit: June 18, 2019, 11:51:56 AM by kumin »

lebmung

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Re: F2 citrange winter hardiness trial
« Reply #157 on: May 19, 2019, 04:11:43 PM »
I used an easy method, in the end of March I gathered fruit that had fallen in the autumn/early winter. After soaking them in water and squeezing/manipulating the fruits, the seeds separated from the pulp. I disinfected the seeds with Sodium  hypochlorite, then rinsed them and planted immediately. Due to recent cool temperatures, seedling emergence has only been evident for the last week. Germination appears to be satisfactory.

I prefer sow them in the fall, by the time spring comes they are 8-10 inches high, this way you extend the season to one year more, because PT stops growing at the end of September. A hormone mechanisms tell him to go dormant. Sodium hypochlorite is toxic and might kill some seeds I use peroxide.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #158 on: May 20, 2019, 05:40:02 PM »
Here is a clearer photo of the 40 cm tall F2 Segentrange with no dieback after a low temperature of -11.8 deg. F. (-24.3 C) in the end of January of 2019. This plant is slow to break buds. It has a number of faults, such as low vigor and very slender growth. I'm not finding much correlation between vigor and hardiness, perhaps the reverse. One benefit of vigor is quicker recovery from cold injury, but vigor doesn't appear to provide much initial protection. Although this plant has short thorns near the base, the upper level is thornless.

I may try to use this plant in further breeding, if it matures and flowers in a timely manner. The partner should probably be one of the most vigorous specimens available.

« Last Edit: June 03, 2019, 03:48:05 PM by kumin »

hardyvermont

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Re: F2 citrange winter hardiness trial
« Reply #159 on: May 20, 2019, 09:28:42 PM »
"Surprise Magnolia grandiflora discovered growing under Poncirus. The first seedling in 22 years!"

What variety is the parent?

Zitrusgaertner

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Re: F2 citrange winter hardiness trial
« Reply #160 on: May 21, 2019, 03:31:37 AM »
Usirius, no, Bernhard has been a little bit out of Citrus in the last years. He has lost most of hir plants after a storm had damaged his greenhouse. I have spent some time with him last summer and last weekend I met him in Vienna at the "Wiener Zitrustage". I wonder what 899-variety you have. The rather hairy fruits look strange to me. I have 4 899-F2-hybrids but only with 2 of them I am sure about the correct marking. I have (for sure) 899A and 899J and (quite sure) 899F and (don't know) 899E or H. All are blooming. 899A has sweet, mandarin-like fruits. 899J did not bear fruits yet and the fruits of the rest are not edible.
899A is monofoliate, 899J aswell, F and H Show trifoliate leaves, but very few with the years.

kumin

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Re: F2 citrange winter hardiness trial
« Reply #161 on: May 21, 2019, 04:24:08 AM »
Hardyvermont, Edith Bogue is the seed parent. It's likely also the pollen parent, but there's a 24 Below tree nearby, that could be the pollen parent.
« Last Edit: May 24, 2019, 04:42:58 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #162 on: May 25, 2019, 04:32:06 PM »
I compare the severity of winter cold by the affect on various cold sensitive woody plant species. I have already mentioned this winter's damage on Kaki persimmons (2 severely injured back to the truck and major branches, 2 killed outright) Bamboo, cold injured  to the ground , Mimosa, delayed growth, but not killed. Today, I cut down  my dead Crape Myrtle that hadn't suffered much injury in the past 12 years, or so.
These 4 trunks were killed to the soil level. These trees had winter top-killed in the past, but not in the last decade.
I previously mentioned the need to classify the F2 survivors into 3 categories:

1. Stem survival above snow level,

2. Stem survival within snow height.

3. Stem survival within snow height-dwarf.

I now need to add a 4th category: survival from roots below soil level. These are obviously less hardy, and will be observed for unusual or outstanding characteristics.

2018-2019 was the most injurious winter in at least a decade, as these crape myrtles were killed to the ground.

My oldest Poncirus tree and offspring are in the background.



« Last Edit: June 05, 2019, 06:09:44 AM by kumin »

SoCal2warm

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Re: F2 citrange winter hardiness trial
« Reply #163 on: May 25, 2019, 07:22:38 PM »
I wonder what 899-variety you have. The rather hairy fruits look strange to me. I have 4 899-F2-hybrids but only with 2 of them I am sure about the correct marking. I have (for sure) 899A and 899J and (quite sure) 899F and (don't know) 899E or H. All are blooming. 899A has sweet, mandarin-like fruits. 899J did not bear fruits yet and the fruits of the rest are not edible.
I have a few seedlings of US 852 as well, so I'm assuming that would be in the same category. (They're just small right now)
They were grown from fruit from Stan's farm, so I'm hoping there may be a chance one or two of them could turn out to be some sort of hybrids. (Thought I think that's probably wishful thinking)

US 852 is probably the only hybrid that's fully hardy well into zone 7 (might possibly even be able to survive borderline 6b as long as it's not too far north).
« Last Edit: May 25, 2019, 07:28:16 PM by SoCal2warm »

lavender87

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Re: F2 citrange winter hardiness trial
« Reply #164 on: May 27, 2019, 04:13:43 PM »
  All effort would be meaningless if we fail to accelerate the ripening time, so their fruits can be harvested before the first frost of winter arrival. Even in zone 8a where I live, people growing Thomasville citrangequat had problems with ripening time of the year. Some versions of citrangequat trees do offer good taste of fruits when fully riped. I know some stubborn folks would upset to hear about unknown hybrid of citrangequat because of their outdated knowledge that citrangequat is a genetic dead end. If someone have questions about whether or not citrangequat could have some zygotic seedling, they can contact Stan Mckenzie to ask about its seedlessness.

   The original Thomasville Citrangequat fruit was described as being seedy and very tart, with mainly trifoliate leaves and thorny, but some of Thomasville citrangequat tree from Stan offered nearly seedless fruits and some have mix foliate with very few trifoliate leaves, some trees even thornless, eventhough they were all come from Stan Mckenzie.
« Last Edit: May 27, 2019, 04:15:41 PM by lavender87 »

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #165 on: May 27, 2019, 04:45:54 PM »
Thomasville is flowering several times in my climate. Spring bloom is giving seeds when cross pollinated by other hybrids in the garden, while during the early July flowering there is usually no other citrus to pollinate it.
This gives seedless fruits. Thomasville seeds are giving only  nucellar seedlings, cross pollination is just necessary to induce  them.
Stamens of Thomasville flowers contain some fertile pollen grains, especially during hot weather. I managed to produce several dozens of its hybrids with 5star citrumelo.
Best regards,
                       Ilya

kumin

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Re: F2 citrange winter hardiness trial
« Reply #166 on: May 27, 2019, 05:57:01 PM »
Ilya, when is 5* ripening in your location? Are your 5* X Thomasville seedlings vigorous?

eyeckr

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Re: F2 citrange winter hardiness trial
« Reply #167 on: May 27, 2019, 10:57:04 PM »
Amazing graft Kumin and good luck with all your trials.

Lavender87 you mention ripening of Thomasvilles. As long as they are sized up and juicy I've always used them like a lemon or lime substitute while they are green and they taste fine. Are you trying to get them to ripen until they are totally orange and eat them whole like a kumquat?

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #168 on: May 28, 2019, 03:12:54 AM »
Ilya, when is 5* ripening in your location? Are your 5* X Thomasville seedlings vigorous?
Usually 5star starts to bloom at the end of April, fruits are yellow by November 10. But  if you keep them after  the harvest until January they are much less acid.

5starXThomasville seedlings are very variable, from the first batch of 20, only three are still alive after two years in the ground.
Last year pollination gave 40 zygotes, only three are as vigorous as nucellar 5stars

 
Best regards,
                       Ilya

kumin

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Re: F2 citrange winter hardiness trial
« Reply #169 on: May 29, 2019, 02:16:34 PM »
Ilya, I believe you have referred to 5*'s impressive storage life previously. What storage temperature has worked best for you? I haven't been very impressed by Poncirus storage duration in the past. It appears 5* is considerable better.
« Last Edit: May 29, 2019, 02:44:11 PM by kumin »

Ilya11

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Re: F2 citrange winter hardiness trial
« Reply #170 on: May 29, 2019, 02:30:58 PM »
I stored its fruits both in a basement with temperatures around +12C as well as at room temperature. Even in March they are mostly undamaged, juice is less sour and actually more abundant than just after a harvest in November, since the flesh is loosing its hardness.
Best regards,
                       Ilya

kumin

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Re: F2 citrange winter hardiness trial
« Reply #171 on: June 08, 2019, 07:18:43 PM »
Presently I am preparing Poncirus seedlings to be used as rootstock under segentrange scions. As soon as the larger seedlings begin new growth they have overcome transplanting shock sufficiently to use as rootstock. The smallest need to grow a good bit in size before use.

There are maybe 800 seedlings not potted at present. 300 + small ones are potted and 130 larger ones are potted of which about 12 have been grafted.

There's a lot of work to be done by autumn of this year.

300 plus recently potted Poncirus seedlings.



Several hundreds of this year's Poncirus seedlings - not potted. Sand used as weed control.


1-3 year old Poncirus seedlings. As they flush new growth, they should be ready to graft.

« Last Edit: June 09, 2019, 11:49:37 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #172 on: June 08, 2019, 07:39:00 PM »
Poncirus contains several gene regions responsible for its freeze resistance and its genome is highly heterozygous. That is why  F1 hybrids with citrus are showing a large variation for winter hardiness.
Three hundreds of its F1 hybrids with very frost sensitive pummelo show a wide distribution of freeze damage.

 article



Quite possible that C35 citrange inherited a rather unfavorable set of gene alleles from its poncirus parent explaining its poor winter performance.


Ilya, considering that C-35 citrange may not include all of the genes providing cold hardiness found in Poncirus, I plan on not only sampling and testing within the segentrange progeny that have survived, but also crossing with the hardiest Poncirus hybrids approaching edibility that are available. I will be winter testing 5* Citrumelo and TaiTri this winter. If their hardiness approaches that of my survivors, they will be considered as parents.
« Last Edit: June 09, 2019, 06:12:35 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #173 on: June 08, 2019, 07:52:10 PM »
The good and the bad:
This clone is the only one to show zero dieback after a low temperature reading of -11.8 deg. F in late January of 2019.
A defect of this clone is the failure to green up properly this spring. There is also overall low vigor. Regular foliar nutrient feeding has been started. This plant may not do well on it's own roots.

If it is possible to overcome it's defects, this plant may be used for breeding purposes, due to it's excellent cold hardiness.

« Last Edit: June 09, 2019, 06:26:09 AM by kumin »

kumin

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Re: F2 citrange winter hardiness trial
« Reply #174 on: June 14, 2019, 07:13:25 AM »
A few current photos:

69 survivors selected for further evaluation - some have serious defects and may not be used for further breeding.


One of the hardiest specimens - all but 1 twig removed as scions for grafting.


2 Monofoliate survivors - appear rather Citrus - like.
 
« Last Edit: June 14, 2019, 09:53:44 AM by kumin »

 

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