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Messages - SoCal2warm

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1
There was a genetic study in Japan that showed that Kishu was one of the parents of Satsuma. Kishu probably has less cold hardiness than Satsuma, however, since it was likely the other parent (kunenbo, also believed to be the parent of Keraji and Bloomsweet) that conferred cold hardiness. My guess is that the cold hardiness of Kishu isn't anything special compared to other mandarin varieties, but mandarins as a group do tend to be fairly cold hardy, certainly more so than oranges.

2
Seeds from hybrid citrus varieties have a strong tendency to show characteristics different from their parents when they are zygotic (the result of sexual recombination). However, in many citrus varieties (especially many hybrids) the majority or all of the seeds tend to be nucellar (not the result of sexual recombination, and thus genetically identical to the fruit parent).
I believe in this case the seeds are more likely than not to be nucellar, but don't know for sure. Usually most mandarins tend to be zygotic while oranges are almost all nucellar.

3
Citrus Buy, Sell, & Trade / Re: Mandarinquat seeds
« on: February 15, 2018, 01:41:22 AM »
Mandarinquat is alternatively sometimes called "Calamandarin"
According to one test, mandarinquat retained all its leaves during cold while Kimbrough Satsuma, Taiwanica, and Sancitchang all lost their leaves, demonsrating that mandarinquat might be better adapted than these varieties (although definitive conclusions should not be drawn from a single anecdotal observation). It could just demonstrate that mandarinquat goes into dormancy easier and/or has a more vigorous growing habit, rather than absolute cold tolerance.

4
Citrus Buy, Sell, & Trade / Mandarinquat seeds
« on: February 15, 2018, 01:31:04 AM »
Mandarinquat is a fairly cold hardy citrus that can survive down to 14 F, it's more hardy than Calamondin but less hardy than kumquat
mandarinquat = mandarin x kumquat
skin is moderately edible, not as good as kumquat
interior is more edible and more flesh than kumquat

3 seeds, 4 dollars (seeds will go out, might send you the bill later)

limited time, probably ending in next few days

5
Cold Hardy Citrus / Re: cold hardy Citrus for zone 7b?
« on: February 14, 2018, 07:45:00 PM »
Are seedlings different from their mother or are they just copies ( not in the meaning of clones, but nearly identical)?
Seedlings can be either "zygotic" or "nucellar". Some citrus varieties produce almost entirely nucellar seed, while some produce all zygotic.
Nucellar are the ones that are genetic clones (exact copies). Certain citrus varieties tend to produce seedlings that mostly resemble the traits of their parents, even though they are zygotic and may not be exact genetic copies. Typically if an offspring is a direct hybrid between two different species of parents the offspring will be more likely to be unpredictable.

I don't know but I would imagine citrangequat would produce mostly to entirely nucellar seeds, based on the fact that both calamondin (orange x kumquat) and citrange are nucellar. (kumquat is zygotic)

6
Those synchronicity problems can be solved by planting one of the trees in more shade. (It doesn't have to be shade, just somewhere were it will get less sun during the Winter months because of the lower angle of the sun in the sky)

7
One Green World nursery in Oregon sells a Citrumelo ...  I'm not entirely sure which variety it is, but it has spherically shaped fruit.  It tastes awful.
Unnamed citrumelo that tastes completely awful is probably Swingle.

Anyone know any sources of a nice sized grafted citrumelo?
Logee's has them too.

8
If the plants are going through Winter in a state of semi-dormancy the minimum temperature should be about 50 F.
To grow, citrus needs a minimum temperature of about 65-70 F. The growth rate will be nearly twice as fast at 80 F as it will at 70 F.
It is okay for the temperature to go down in the night but generally you don't want a temperature drop of more than 17 degrees or so (between day and night) because that can encourage leaf drop. At about 89 or 90 degrees I'd start being concerned about overheating.

Seedlings should probably be kept above 68 at all times, and prefer a warmer 76-79. Too hot isn't necessarily good, it can cause the soil to dry out or encourage root rot of the seedlings.

(all these numbers are very approximate)

9
Citrus General Discussion / Re: My first Kishu mandarin harvest
« on: January 28, 2018, 11:50:32 PM »
Kishu is actually believed to be one of the parents of Satsuma (unshiu mikan), according to DNA studies that have been done in Japan.

10
Citrus General Discussion / Re: Anybody growing Tahoe Gold Mandarin.
« on: January 28, 2018, 11:45:15 PM »
I have to say I'm a fan of Shasta Gold (I think it might even be a little better than Page mandarin). Not sure how similar it is to Tahoe Gold though. (I'm not a fan of Dancy, so that should be saying something)

11
Tropical Fruit Discussion / Re: LED Grow lights
« on: January 28, 2018, 10:17:18 PM »
It's not "theoretical", it's basic physics.  The amount of photons you get is always  the efficiency times the amount of energy per photon times the input power.
It's not as simple as that.
If we were talking about generating photons with 100% efficiency and having them be absorbed by a single molecule of chlorophyll, then yes you would be completely right.


Here's a real world test that shows the difference between growing a tomato plant under a 38 Watt red+blue lamp versus a 50 Watt white LED lamp:

https://www.youtube.com/watch?v=HawgP5SXPko

Obviously not exactly a fair comparison because of the difference in wattage but the plant grown under white light obviously does much better.

Here's another experiment that shows plants grow better under white LED light than they do under either red or blue light alone, keeping wattage equal:

https://www.youtube.com/watch?v=mwwLSgK-924

12
Tropical Fruit Discussion / Re: LED Grow lights
« on: January 28, 2018, 08:17:38 PM »
The problem is that you don't get nearly as many photons per watt with white as you do with red-blue.
That's true.
Which is why theoretically red-blue is the most efficient (but again that's very theoretical, and may depend on a number of other factors).

Photosynthesis is carried out on a per-photon-absorbed basis.
Not sure I agree on you there. Light absorbed by the leaf does not automatically mean it was necessarily converted to energy.
I think while green light has a much lower absorption rate (and thus lower conversion), of the light that is absorbed it may have a higher conversion efficiency.

(This isn't an argument for using green LEDs, since current technology green LEDs have the lowest amount of efficiency, about half that of red or blue)

But they're not huge
I agree.

Red LEDs are moderately efficient and red photons are cheap to make
 Red is simply the cheapest way to drive photosynthesis
Yes, theoretically if you just wanted to dump energy into the plant red LED would be the best way to go about it.
(Although plants don't seem to grow very well unless they have some blue light)

white, yellow, green, and amber LEDs are very inefficient.
Actually white LEDs are not that inefficient (although they're certainly less efficient than blue).
I'm just saying it wouldn't be a terrible terrible loss if you tried to use white LEDs to grow plants, especially at the higher color temperatures.

Look at the LED fixtures that commercial greenhouses use.  Look at the fixtures that NASA uses.
I wonder if NASA has ever run side-by-side tests comparing plants grown under red-blue light and plants grown under different combinations of red-blue and white light.

If NASA was really aiming for optimal energy reduction then one would assume red-blue would be the way to go, but it may well be sacrificing growth rate.
That is, if you're going to under-power the plants, then you probably could get away with higher efficiency using less light.
But these are not necessarily the same growing conditions everyone is going to use.

I've never come across any study comparing red+blue lighting to red+white, or red+blue+white.


This is simply not true.  Check out umol/s/W figures for commercially available fixtures from the same manufacturer.
It's more likely true for the cheap LED grow lights.


I'm just saying that plants are more likely to grow better under red+blue+white than they are under just red+blue.

I did see one study that compared different combinations of red-green-blue wavelengths, but the study is not directly applicable here since they were using a green emitter, which has substantially lower efficiency than the green wavelengths coming from a white LED, and for other reasons.

I'm saying that if you had to compare between using a cheap red+blue grow light and just using a regular white LED bulb, you might not be so bad off deciding to use the bulb.

13
Tropical Fruit Discussion / Re: LED Grow lights
« on: January 28, 2018, 07:24:47 PM »
If you're spending less than $30 for a cheap red + blue LED grow light manufactured in China, it very likely (read: almost certainly) won't actually be the wattage claimed. (If it claims to be 45W it will very likely actually be 32W, as an example)

Furthermore the overall efficiency of these lower cost grow lights are likely to not be as high as a typical white LED bulb you can find at the store for very cheap. So, I would ask, are you really gaining much advantage by using a special red + blue grow light? At the very least you might think about some combination of the two together.


14
Tropical Fruit Discussion / Re: LED Grow lights
« on: January 28, 2018, 07:08:15 PM »
I've seen an experiment that showed plants grow better under regular white LED light than they do under red + blue grow lights. This is apparently because other wavelengths of light are important too. There are different photosynthetic pigments that absorb other wavelengths, so I think if you're just using red + blue, some of the photosynetic receptors might be getting overstaturated (i.e. there's only so much energy the plant can absorb from any specific wavelength). However, I've also seen another study that showed higher growth efficiency the more red there was. I'm pretty sure red is the most efficient wavelength at driving photosynthesis. So ideally then, the optimal mix would involve both red and white light.

Another reason other wavelengths of light are important (i.e. green or white) is because blue light actually has limited penetration through the tissues of the leaf, since it get absorbed so strongly. This limits the utilization of this wavelength in the leaf. Wavelengths less strongly absorbed (such as green) will have much better penetration and be able to drive more photosynthesis, paradoxically. If you're only using blue wavelengths, you'll just be over saturating the chlorophyll on the surface layer of the leaf and it won't do as much good. Deep red wavelengths of light have medium penetration, somewhere between blue and green.

In addition, there are two different peaks of chlorophyll absorption, since there are two types of chlorophyll, 660nm and 620nm. Several of the photosynetic accessory pigments dump their energy to the 620nm type. So by this reasoning perhaps 620nm (red-orange) could just be used instead of white light, but I don't really know.

One last thing- blue LED emitters have become very efficient now and so the efficiency of using white LED light (white LEDs are driven by blue emitters) by itself is not going to be more than 20% less energy efficient than using any other combination that also uses red LEDs. There's simply been a lot more research going into trying to make blue LED emitters more efficient because they're used in white LEDs, which have become ubiquitous for general lighting purposes. This despite the fact that the theoretical quantum efficiency is lower, having to generate a wavelength that requires 25% more energy, with a small degree of additional loss in the phosphor conversion to the other wavelengths (white light).

I might also point out that the theoretical optimal mix probably depends on the light intensity level. If you're not using enough light then I would say red would be the most important, followed by a small amount of necessary blue (to signal the plant to grow). At very high light levels oversaturating the plant then white would be the most important, I think.

As for me, what I'm doing is using 5000K bulbs, the highest efficiency ones I can find that are not too expensive, and supplementing that with some lower wattage "energy saving" halogen bulbs, although in one case I'm using a 660nm deep red flood lamp instead. The idea is that the halogen (a form of incandescent) has plenty of deep red wavelengths, and anyway the small amount of additional heat they're giving off isn't hurting. (Hardly makes sense not to be using incandescent light if you're also running an electric heater at the same time) All in all I'd say the overall wattage is evenly split between the halogen and LED. If I was running a large scale commercial operation I would probably be choosing a mix of 660nm deep red, white LED, and perhaps a small amount of added blue. Perhaps a little 620nm if it wasn't too costly to add it in.

15
Tropical Fruit Discussion / Re: Lychee in So Cal 2018
« on: January 28, 2018, 06:20:33 PM »
Think on the positive side, even if there's no fruit it should still be a very good growth year, which is good because lychee trees are slow growers (especially in the SoCal climate). The bigger and more mature the trees become, the more proclavity they will have for fruiting later.

16
Cold Hardy Citrus / Re: Citrus in the Pacific Northwest
« on: January 28, 2018, 05:55:54 PM »
Very unusual weather this year. Although there was snow in early November (very unusual), what's even more unusual is that so far, since then, there has not been a freeze, as far as I'm aware. Daytime temperatures have been hovering at about 46 F almost every day, maybe 41 in the night (with just a few of the coldest nights down to 36 at the lowest).
 There was a rose on my bush blooming on New Years Day with several more buds that looked about to bloom, and I also just yesterday saw several blooms on a huge camellia bush. With temperatures like this a normal citrus tree could probably be left outside unprotected (although its leaves would have gotten a little frost bitten from the freak freeze in early November). It seems while the rest of the country has been experiencing deep freezes, the West coast has been unusually mild this year.

17
I can tell you that the small mangosteen plants are extremely sensitive, even to mildly cold weather, but also other things. I wouldn't try permanently planting it in Orange County unless you live in the more temperature moderate part, and have a good microclimate and spot in the yard for it, where it will be surrounded by other plants, partially shaded, will mostly only get morning sun, will get more sun into the Winter when the sun is at an angle, protected from wind, etc. In other words all the conditions would have to be completely optimal. I believe it's theoretically possible but you'd really have to know what you're doing, and have the right spot for it.

Do not put the seedling in the ground!
Nurture it and wait till it's at least 2 feet tall until you even think about leaving it out. And even under optimal conditions it may be quite some time before it reaches 2 feet tall, they've been extremely slow growing for me, and I have the temperature and humidity set at a perfect level.

I was told by the owner of ONG nursery that he knows of some Vietnamese people in Hacienda (out in San Diego, neighborhood close to the beach) that are growing Purple Mangosteen outside in a container, leaving it outside during the Winter under their patio, and that they got at least one fruit. That's what he told me, as best I can remember. That area is bordering on the edge between zone 10 and zone 11 so don't automatically think that success will transfer over to where you are.

Also realize the West Coast has had a very mild Winter this year.

18
mangosteen and lychee, temperature kept at a constant 77-79


the one in the very front is a citron

19
One solution would have been to place large plastic trash bags inside of the bins and then line the edges with foam and bunched newspaper so the water would be able to expand after freezing.

Or to just fill the barrels with a bunch of smaller water bottles that are each only 90% filled.

Also, the propylene glycol people buy for fog machines can act as an anti-freeze if mixed in the water. It's pretty environmentally benign. (Although you'd have to use one third by weight propylene glycol to lower the freezing point to 0F, I just looked it up on a graph)

Denaturated ethanol goes for about $70 for a 10-gallon container, but isn't much better at lowering the freezing point. (30% by weight will lower the freezing point to -5F)

Hmm, I wonder what would happen if you just placed a long cylindrical plastic bag full of styrofoam chips down the middle of the barrel. That way the water would have room to expand. Maybe tie it down with a cinder block.

20
Cold Hardy Citrus / Re: Citsuma Prague
« on: January 10, 2018, 04:47:49 PM »
It's not as likely, but one possibility is it could be a triploid, if one of the gametes was unreduced. (This can occasionally happen by natural processes) That could potentially have left the entire genome of one of the parents intact. (In that case it would be 2/3 poncirus and 1/3 mandarin, or 1/3 poncirus and 2/3 mandarin)
Being a triploid would also explain lack of seeds or low seed count.

(for those of you who may not understand, occasionally during production of the plant's reproductive cells meoisis fails to take place, and then the reproductive cell has the full set of two chromosomes, so when it later combines with another reproductive cell the resulting zygote will then have three sets of chromosomes, instead of the usual two that most citrus plants have)

21
See these videos, using the ground deep down as a thermal battery:

https://www.youtube.com/watch?v=o2NtBCS2_WQ

https://www.youtube.com/watch?v=IZghkt5m1uY

22



How about Duncan Grapefruit crossed with Sumo Citrus (i.e. Dekopon)?
I bet that would have really good flavor.
(now if only I could find any seeds in the Sumo...)

23
I believe that being in a container has a natural dwarfing effect on the tree, constraining the root growth, so I believe it may not matter too much how dwarfing the rootstock is.

24
Or how about a cross between Minneola Tangelo and Chandler pomelo?



25
The Valencia oranges were rather underformed (and to be honest were not really ripe). The tags on them said imported from Mexico.
The local store has some really good variety and eclectic selection. Two months ago they had Cox's Orange Pippin apple. Never thought I would see that in a store.
It's also the same place were I sampled Jupiter grapes (grapes that taste like lychee!) sourced from a local farm. I don't have time to go into it right now but it's definitely not your normal store.

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