Hardy citrus trees for zones 6 and 7.

[Walt]

There is active breeding of citrus winter hardy in zones 6 and 7.  There are people working on it: 2 in Germany, 1 in France, and in USA there is 1 in Pennsylvania, 1 in Georgia, 1 in Kansas (me), 1 in Washington, 1 in Tennessee (or 2).  And this winter 2 or 3 more have said they are starting.  None that I know of have taken the open source pledge to not patent our work, but we are sharing our breeding stock. Sometimes a price is charged, often there is only postage charged.  Sometimes seed given without even price of postage.  In addition there are people who have collections of  hardier citrus who share their collections. Some make a living doing it on a large scale.  Some are hobbyists.  In addition, there are people who have volunteered to grow out seedlings for those who are breeding.
The breeder in Pennsylvania has 4 year old seedlings that have survived 3 Pennsylvania zone 6 winters.
This work is at tropicalfruitforum.com . 
I'm posting this because I think it will interest some people here.  But as I said before, it is not strictly open source, though in practice it is acting like it is open source.
Speaking for myself, my work on corn and beans and such that I sometimes join in the discussions here.  Those are open source.  My tree breeding, we'll have to see. 
I'm putting a significant amount of money into it while living at below official poverty level.  One gets tempted.  But it will take decades more.  For now, I'm more interested in success than in making money.

[Steph S]

That is interesting, and kudos for the worthy project.  If I was in zone 6 I'd be interested for sure.

After a lot of reading this past year, I've come to the conclusion that not everything should be OSSI pledged.  It's too bad that OSSI excludes PVP, because there's nothing wrong with PVP as a means of compensating independent breeders.  I mean, PVP was set up and internationally agreed on as a way to encourage independent breeding by small seed houses or individuals and thus diversify the offerings on the market.  That stream of breeding still exists in spite of "big five".  But when material is OSSI pledged, it is basically removed from that stream of diversification, because no independent breeder can use it with the expectation of a fair return via PVP. This is fine for breeders with university positions, who are salaried and have no need of PVP to pay for the work.  OSSI pledging requires some serious altruism on the part of an independent breeder working without a salary, especially since it is not just the one variety but all its progeny that are barred from breeding use for reasonable compensation, as well as from the utility patents which are the real problem.
I'm now thinking that the OSSI pledge is most suitable for the kind of projects that cross public domain material (heirlooms, wild relatives etc) to gather in some genetic diversity to the pool that university professionals can freely use for open source projects, but doesn't invest too much in the process of selecting something special and stabilized, and doesn't lean to heavily on the work of independent breeders/small seed houses. 

So you certainly shouldn't feel bad about working on something that remains in the stream of germplasm which independent non-university breeders can build on to produce new works.  I think the PVP on trees and other material propagated by cloning or grafting is 25 years, in which the breeder can have exclusive control of propagation and sales.  It doesn't stop the material from being used for breeding immediately but they buy it from you or your chosen agents and thus you get a return on your effort.

Also I would hope that all discussion of independent breeding projects is welcome here, even if they aren't OSSI pledged. 
Maybe the OSSI pledge will be revised at some point to be more inclusive of reasonable compensation for the independent breeding stream.

[Walt]

Yesterday I posted a link to tropical fruit forum.  Later I realized it has hundreds of pages on  all kinds of fruits and people not familiar with it wouldn't quickly find much on breeding hardy citrus.  So here is a link to Kumin's work.  20 pages of how he started, his results so far, and .  The last few pages are describing fruit from his tree seedlings that have survived 3 Pennsylvania winters.

https://tropicalfruitforum.com/index.php?topic=30891.0

And here are my 3 pages on my work so far and thoughts on future work.

https://tropicalfruitforum.com/index.php?topic=45583.0

[Jeremy Weiss]

That is interesting, and kudos for the worthy project.  If I was in zone 6 I'd be interested for sure.

After a lot of reading this past year, I've come to the conclusion that not everything should be OSSI pledged.  It's too bad that OSSI excludes PVP, because there's nothing wrong with PVP as a means of compensating independent breeders.  I mean, PVP was set up and internationally agreed on as a way to encourage independent breeding by small seed houses or individuals and thus diversify the offerings on the market.  That stream of breeding still exists in spite of "big five".  But when material is OSSI pledged, it is basically removed from that stream of diversification, because no independent breeder can use it with the expectation of a fair return via PVP. This is fine for breeders with university positions, who are salaried and have no need of PVP to pay for the work.  OSSI pledging requires some serious altruism on the part of an independent breeder working without a salary, especially since it is not just the one variety but all its progeny that are barred from breeding use for reasonable compensation, as well as from the utility patents which are the real problem.
I'm now thinking that the OSSI pledge is most suitable for the kind of projects that cross public domain material (heirlooms, wild relatives etc) to gather in some genetic diversity to the pool that university professionals can freely use for open source projects, but doesn't invest too much in the process of selecting something special and stabilized, and doesn't lean to heavily on the work of independent breeders/small seed houses. 

So you certainly shouldn't feel bad about working on something that remains in the stream of germplasm which independent non-university breeders can build on to produce new works.  I think the PVP on trees and other material propagated by cloning or grafting is 25 years, in which the breeder can have exclusive control of propagation and sales.  It doesn't stop the material from being used for breeding immediately but they buy it from you or your chosen agents and thus you get a return on your effort.

Also I would hope that all discussion of independent breeding projects is welcome here, even if they aren't OSSI pledged. 
Maybe the OSSI pledge will be revised at some point to be more inclusive of reasonable compensation for the independent breeding stream.

Well, I'm sure that there are some people (like me, sometimes) who would argue that breeders have an obligation to forgo any compensation for their product in order to make it available to as many people as possible, that they fact that they CAN do something of potential benefit to other obligates them do do so, no matter the personal cost. But, of course, this only makes sense within my off the way philosophy of absolute altruism, where the goal of every person is to live ONLY for others with no consideration for themselves, and willingly offer themselves to be totally used up by society and then discarded without thought. After all, the purest form of selflessness isn't self-deferment or self-denial, it is self-destruction.

But bear in mind my therapist is trying to talk me OUT of that philosophy.

As for cold hardy citrus, I left a whole pot of Yuzu seedlings outside for the winter this fall, to see if any make it through. If they do, I'm putting them into the ground and they are STAYING there. It just might work, the last time I did it (by accident) come spring, the sticks DID still have green cambium (unfortunately, I only discovered this AFTER having pulled them up thinking them dead to re-use the pot; I'll wait longer this time.)

I'm assuming that, if the Yuzu's can take it here, my sudachi can as well, so that will also get a spot in the ground.     

[Steph S]

I read your 3 pages, Walt.  Wow that's quite a project.  Just the wait alone for trees to be producing flowers/pollen as required is going to take some dedication. 

@Jeremy Weiss, I started vegetable breeding purely for the use value, since our climate is harsh and fickle the goal of food security is the big one, so it was never intended as a 'for profit' pursuit, it is meant to benefit the community (and myself and family directly with food).
IDK if that is altruism, but since seed is shared with my local farmer contacts, I would call it mutualism, more like it.
I always intended to distribute my finished seed through the same free seed exchange network that the parent plant seed came from.  Charging money for seed is not permitted in these networks.  Again it is mutualism more so than altruism, to return seed to the place it came from.  Perhaps your therapist might like that idea better?

[Tim DH]

Hi Walt,
   Thanks for kicking this thread off.
   In England, one additional problem we have, beyond the cold, is lack of Winter light.

   I'd not previously heard of Yuzus. But the idea of a citrus that might fruit in the Autumn, before our light levels plummet, AND then be hardy enough to survive the Winter is very appealing.

   Once again, the problems of getting material to work with in the UK is frustrating. But I think I've sourced some Yuzu seed.

Tim DH

 

[Tim DH]

Encouraged by this thread, I've once more dipped my toe in the Citrus water! (I've long harboured a desire to grow my own marmalade.)

Yuzu seed arrived today. ... From Bulgaria!
The vendor included some trifoliate as a gift. To make rootstocks.
I didn't think Yuzu would need grafting. .. Any opinions?

Does anyone have a preferred reference website for citrus grafting protocol?

Tim DH

[Jeremy Weiss]

I was told a Yuzu can comfortably grown and fruit in a one gallon pot. Grafting might speed things up a bit if you already HAD the rootstock ready, but if you are going to have to grow THAT from seed as well, I doubt doing the graft will save you any time.

Speaking of marmalade, my bergamot seedlings are up. And, sometime around April I think, I will be getting two Baladi Lemons (the small kind favored in Morocco for pickling). 

[Mikkel ImGrimm]

Hi Walt,
   Thanks for kicking this thread off.
   In England, one additional problem we have, beyond the cold, is lack of Winter light.

   I'd not previously heard of Yuzus. But the idea of a citrus that might fruit in the Autumn, before our light levels plummet, AND then be hardy enough to survive the Winter is very appealing.

   Once again, the problems of getting material to work with in the UK is frustrating. But I think I've sourced some Yuzu seed.

Tim DH

Can't you import seeds from the USA? UC Riverside sometimes sends seeds.

[Tim DH]

Hi Mikkel,
    Thanks for the UC Riverside prompt. Their page on Yuzu is very informative:

https://citrusvariety.ucr.edu/crc1216

    Going forward, what I think I want is seed of a modern early Japanese variety. SO about September time I'll put out some feelers to Japanese connected friends.

    Meanwhile I've got my Bulgarian seed to play with.

Hi Jeremy,
    Thanks for your thoughts on grafting. ... That's similar to what I thought. Either way I have much more Yuzu seed than trifoliate seed. Which logistically speaking means most of the Yuzus (assuming reasonable germination) are going to be own roots anyway.

Tim DH

[Jeremy Weiss]

Hi Mikkel,
    Thanks for the UC Riverside prompt. Their page on Yuzu is very informative:

https://citrusvariety.ucr.edu/crc1216

    Going forward, what I think I want is seed of a modern early Japanese variety. SO about September time I'll put out some feelers to Japanese connected friends.

    Meanwhile I've got my Bulgarian seed to play with.

Hi Jeremy,
    Thanks for your thoughts on grafting. ... That's similar to what I thought. Either way I have much more Yuzu seed than trifoliate seed. Which logistically speaking means most of the Yuzus (assuming reasonable germination) are going to be own roots anyway.

Tim DH

Which kind you want sort of depends on what you plan to use it for. When the Japanese use a Yuzu, they're mostly interested in the oil from the rind, so that is the part that keeps getting increased. So, the more modern the variety, the less actual flesh will be inside it, and the less juice you will get. The Japanese will USE the juice if it is there, but it is an afterthought at best*. That's why I used to look for the OLDEST varieties I could**, I wanted one with LOTS of juice.

And you may not wind up with as many seedlings as you think. One thing I forgot to mention is that Yuzus, with their jumbled up genes, have a pretty high incidence of non-viable seedlings. You'll certainly get enough to work with, but you can expect maybe 5-10% to have some sort of defect that will make them no good, like never producing leaves or being albino.

*I'm not totally sure what part is used in yuzu flavored drinks, the peel essence, the juice, or both.

**While I am still growing the yuzu plants I have, the fact that I can't actually EAT them anymore (due to the interactions of the furocoumarins in then with the statins I take for my cholesterol.) have sort of tempered that hunt. That's part of why I was willing to leave them all outside for the winter this year to see if they come back, if they don't I haven't really lost anything.   

[Mikkel ImGrimm]

This is a link to a list of different yuzu varieties.
Actually, most of them are juicy varieties.

http://viaggiatore971.blogspot.com/2016/12/agrumi-rustici-citrus-cold-hardy.html?m=1

[Mikkel ImGrimm]

If you are allowed to import fruit. Pepiniere Vessieres sends a fruit basket with different varieties. e.g. Yuzu

https://agrumes-vessieres.fr/categorie-produit/nos-fruits

[Tim DH]

Hi Mikkel,
   Thanks for the links. ... The Italian website is great. It's premise is very close to mine. Sadly the author seems to have fallen silent in 2021. Still an excellent resource.

   The French 'Fruit Basket' offering I had already discovered. They were/are all out of stock so I didn't probe any further. However following your link, I dug a bit deeper and found that they also seem to sell plants. Tho likewise these are mostly out of stock, but the website has been recently updated.
   Their description of Yuzu N1 seems to be exactly what I'm looking for:

https://agrumes-vessieres.fr/produit/yuzu-n1

   Probably, getting a plant will be impossible, but next Autumn I'll try getting some fruit!

Tim DH

[Walt]

I don't know how well yuzu will do for you.  But people on the tropical fruit forum say that grafting high (1 meter or more) on trifoliate orange makes the scion hardier to winter cold than it would be on  its own roots.
Also some people make and like marmalade made from trifoliate orange which should be hardy most places.  That said, most people WON'T  eat eat anything made from trifoliate orange.  Then again, there is a mutant of trifoliate orange without the resinous flavor of other trifoliate oranges.  So people say it tastes much better (mine hasn't fruited) than the origional trifoliate oranges.  Both are still very sour.