This chinese seller has some similiar hardy varieties from China. I asked for Jiouyuezao some years ago but back then they don`t had it. Maybe now?
They offer
Citrus reticulata (Tuanianiju)
Citrus reticulata (Bendizao)
Citrus reticulata (Xingjin)
Citrus reticulata (Zaojin)
Hi,
This link sadly does nothing for me now. However I have read about some of these in this study:
https://www.fao.org/4/x6732e/x6732e12.htmAt the end of it there is a list of some Chinese varieties and Zaojin Jiaogan is mentioned there as a selection of Xingjin. Now Xingjin suffered no damage at -12C. That means it can probably survive -15C with some defoliation and slight dieback. That would make it probably the hardiest Satsuma if it's true.
In another work I read Zaojin Jiaogan fruits' picking time ranged from mid September until mid November in a fruit quality experiment. So the early ripening is there. If it's as hardy as its mother Xingjin, this is even better than Jiouyuezao. Good hardiness, early ripening and Satsuma quality - all I need from a mandarin.
Now back to the study I linked. When it speaks of cold resistence, it refers to a former study on cold hardiness. That was done at Huazhong University, Hubei. In the meantime I accidentally found some Chinese stuff at UCR:
https://citrusvariety.ucr.edu/crc4061It says a group of mandarins were sent to.them from the same Hubei. I have no idea if any of these are the same as mentioned in the study or not, but if they are, sooner or later these may become available for the public, probably under a new fancy name. If all the data published in the study are true, and those mandarin varieties can do justice for themselves also at different locations than their homeland, then some new zone 7 holy grails may be born. That is, if all those published details are correct which we can only hope.
By the way, there is another interesting one listed called Meizhou Summer Jiaogan. Its ripening time is mid May-mid June. Now can it be an early flowering one that grows its fruit in about 2 months to ripen that early? Very unlikely. But most mandarins usually don't mess a whole year doing it, either. Anyhow, I wrote to two Chinese universities which did those field tests. I don't expect a reply antime soon, if any at all. But an email is free and worth a shot and I asked them about all the ones mentioned above.
So I am afraid we aren't any closer to Jiouyuezao here in Europe. But if Chinese or other sellers offer Zaojin and Xingjin again, they might be worth a shot. And they may even be better than Jiouyuezao. I wonder if UCR made any progress with those Chinese mandarins.
Topic: Wanted: Citrus reticulata 'Jiouyuezao' (Read 3971 times)