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Messages - kumin

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Cold Hardy Citrus / Poncirus+ early bud break
« on: March 09, 2020, 06:43:54 AM »
There's been at least one post questioning Poncirus+ winter hardiness. Due to experiencing a very mild winter, I can't really address it's ultimate winter hardiness, except noticing that they're the only trees showing bud-break this early. None of the citranges, other Poncirus, TaiTri, 5* citrumelo, Ichangquat, etc. are showing bud-break. Perhaps this early loss of dormancy contributes to decreased hardiness.
It remains to be seen whether the remainder of the selections will follow within days, or will remain dormant for several additional weeks.

Citrus General Discussion / Re: Record buck farms
« on: March 04, 2020, 01:39:01 PM »
Flushing a cutting's foliage depletes stem reserves.  Plants need and seek root/foliage balance. A plant with foliage removed, ideally will replace foliage as a response, not root initiation. Likewise loss of roots ideally will be followed by new root generation. Reducing stem temperatures, while maintaining root warmth is one path toward initiating new root development .
I rooted many woody plants in the past. The plants were maintained under shade cloth, with about 50% of the foliage removed to reduce transpiration. Additionally the cuttings were automatically, periodically misted/fogged to cool the stems and retain turgor.

Woody plants differ in rootability by season, by species and cultivar, by degree of lignification (maturity within season), by rooting hormone dosage, by juvenility of propagation materials, and rooting media selected. Mother trees are often deliberately keep in a vegetative state by severe pruning to force new, more easily rooted growth. The base of a cutting (the lowest portion of a flush of growth) has the greatest rooting potential.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

Cold Hardy Citrus / Re: Citrus in the Pacific Northwest
« on: February 16, 2020, 03:02:35 PM »
If the Acrtic air continues to descend into Eurasia for another 6 weeks, there may be a lot of unharmed North American Citrus this winter. No guarantees that will be the case, though.

Citrus General Discussion / Re: Paired thorns on F2 citrange
« on: February 13, 2020, 08:46:53 PM »
You are correct, Ilya. The seed orchard being nearly 3,000 miles away, there's no way to be certain of the configuration of the parent tree layout. The one likelihood is that the pollen originated from trees blooming at the same time.
Having no connection to the industry, any other conjecture would be idle speculation.

Cold Hardy Citrus / Re: Arctic Frost Satsuma experience
« on: February 11, 2020, 09:36:10 PM »
My understanding is that frost cloth is most effective when it covers the entire canopy, then drops straight down and is secured to the soil with no gaps. The perimeter at soil contact should be the same as the canopy perimeter. The frost cloth should not be tied to the trunk at the soil line.

The objective is to capture the slight warmth rising from the soil under the tree. The frost cloth serves as a modest thermal barrier between the soil and the cold night sky, with the tree being within the protective envelope.

The effect can be further enhanced by temporarily covering the frost cloth with poly film. This is most beneficial under windy conditions. During sunny days this can create excessive heat being trapped under the covers, so it's best to use poly film in temporary, extreme conditions. Cooking the plants is not preferable to freezing them!

Citrus General Discussion / Re: Paired thorns on F2 citrange
« on: February 07, 2020, 08:34:54 AM »
I'm fairly close to agreement with your premise. By virtue of selecting for the extreme cold hardy genetics found in Poncirus, there is also by necessity, a similar selection against many desirable Citrus genes. The hybrids selected do, however, have genetic diversity amongst them. There are monofoliate, as well as nearly thornless individuals in the hardy population. The critical question is which Citrus genes are still present in selected breeding stock.

By maintaining the hardiest population as breeding stock, the cost and  complexity of overwintering the plants can be lowered.

It's interesting that eyeckr played a role in the introduction of this cultivar.

The speaker repeatedly refers to "grapefruit". Is she suggesting that the fruit can be used similarly to a grapefruit? My recollection is that grapefruit has the same meaning in both Russian and English.

Citrus General Discussion / Re: Paired thorns on F2 citrange
« on: February 04, 2020, 02:51:05 PM »
Conestoga is the name given to a number of cold hardy F2 citrange survivors from a trial in the winter of 2018-2019 in the southeastern part of Pennsylvania, USA. None of these have fruited at present, so naming them may be premature.
Their only claim to fame is having survived -11.8 deg. F. (-24.3 C) in January of 2019 without protection against the winter temperatures. Except for cold hardiness, little is known about their characteristics.
The 12  surviving plants came from an initial population of 20,000 C-35 citrange seedlings of which 85% were nucellar seedlings. This trial is still in it's relatively early stages.

Citrus General Discussion / Re: Paired thorns on F2 citrange
« on: February 04, 2020, 11:50:33 AM »

There are additional grafted scions of this clone showing the same thorn twinning. Apparently it's an identifying characteristic of Conestoga #11.

Another twin thorn #11 scion.

Citrus General Discussion / Paired thorns on F2 citrange
« on: February 03, 2020, 10:51:44 AM »
I've noticed a twig with 3 consecutive sets of paired thorns on a F2 citrange specimen. Some distant Citrus relatives are armed with paired thorns,(Hesperethusa crenulata on occasion) I'm not certain how common this feature is among Citrus. Hesperethusa's compound leaves have a resemblance to Poncirus, although fruits and bark are quite different.

I see there's an additional pair at the base of the scion.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

Congratulations on your Citrus collection. In regards to using Google translate, over the past 2 years I've done a lot of English-Russian translations. 2 tips that I use are doing a reverse translation to see if the results are still coherent and translating through a third language with which I have some familiarity (Spanish, or German in my case). If the translation transmits clearly and comprehensibly, I'm satisfied that it's an acceptable translation.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: January 27, 2020, 08:45:44 PM »
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.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« on: January 26, 2020, 12:02:28 PM »
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).

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

Cold Hardy Citrus / Re: F2 citrange winter hardiness trial
« 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.

In regards to zygotic seedlings, C-35 is approximately 15% zygotic. Carrizo and Troyer can be as low as 1-2 % zygotic. I have no experience with Carrizo - Troyer cold hardiness. C-35 performs best in uniformly cool winters (within limits). C-35 does not fare as well in areas prone to sudden freezes following warm periods during winter. The references I've seen consider the three to be similar in cold hardiness.

Temperate Fruit Discussion / Re: Persimmon (Diospyros kaki) in Poland?
« on: January 04, 2020, 08:41:16 PM »
Although well drained soil is best, persimmons have considerable tolerance to clay soil. Wet soil is tolerated better in cold temperatures than hot weather, as the need for soil oxygen is lower in winter. Sandy soil is fine as long as the soil has adequate fertility and moisture.

Temperate Fruit Discussion / Re: What varmint could this be?
« on: January 04, 2020, 08:28:55 PM »
Groundhogs are diurnal herbivores, skunks dig extensively for grubs. I believe skunks are fairly precise in their digging.

Mikkel, when I initially saw the 95% zygotic embryos for US 1282 , I was a bit skeptical there might be an error. However, I've just received conformation that it's correct. So if it's possible to obtain a clone and produce one's own parent seed trees, there is the potential of producing large numbers of zygotic F2 seedlings. 

Tables with rootstock seed germination, polyembryony, etc. characteristics. From University of Florida.

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