First fruits of Citrangeremo

[bussone]

It could that I have that Eremomandarin but cannot definitely tell because the picture is not sharp enough. My Eremomandarin is a small bush (~40cm) but has already flowered two times. But I got no fruits up to now. Maybe because I did not water it enough in the year when it was full of flowers. I believed the earth was moist but it wasn't.

I have E. glauca, also. It is not big (~40cm)) but has already flowered. I used the pollen but got no fruits. My impression is that E. glauca needs a lot of light and probably also heat. It did not do well at a position where other citrus plants were happy. I put it into a pot again and placed it in a greenhouse with full sun over most of the day. It immediatelly grew better.

I do not know for sure what can be the greatest contribution of E. glauca for breeding hardy citrus. Perhaps its drought adaption. That may help during winter when the ground is frozen. Another contribution might be winter dormancy. My original idea was that the drought adaption of Poncirus (sunken stomata in the twigs) and the drought adaption of E. glauca (all stomata sunken, deep roots) could greatly help avoiding frost damage. I still believe it. The question is only whether a combination of E. glauca and Poncirus is helpful for me in special with my cool atlantic climate. I fear all E. glauca hybrids require to much warmth in summer to grow sucessfully unprotected in my garden. Perhaps those living in a more continental climate should rather place their hopes in E. glauca hybrids.

Glauca probably has utility someplace like Arizona or Texas, where it needs to deal with blast-furnace summer drought, but where it can also encounter a transient freeze, too, or some winter aridity from wind.

[Till]

And it is hot enough in Texas.
I would be interested how Citrangeremo performs in Texas. It is possible that it even produces pollen under hot conditions. My Citrangeremo stood not really in a cold enviroment when it bloomed so I would have expected pollen. But I know that Kucle and Sucrena only produce pollen when it is really warm. So it might be that Citrangeremo just needs more heat to produce pollen and that Texas is hot enough. If that is the case Citrangeremo would be a great starting point for further breeding together with the other E. glauca hybrids.

[Till]

The remains of my Citrangeremo:





Saidly to say: My Citrangeremo had indeed some kind of root problem and died this year with the beginning of the first hot days. No growth, leaves were more yellow than last year and dried up very soon. I assume that some kind of fungus was the reason. But I did not see infections in the trunk.

What does that mean for my fruit evalution? Hmm, I am not sure. We have to recogn with the case that fruits would have been better when the plant had been more healthy. It may also have happened that it had produced viable pollen and seeds when it had been more healthy. Yet, I have doubts what regards the latter possibility. I have a big Swamp Lemon tree in the same greenhouse that got a cerious fungus (mildew) infection with similar symptoms as the Citrangeremo. But it produced a normal amount of pollen and even viable seeds. The Swamp Lemon tree is not totally dead. It has new growth from lower parts. So the cases are not idential, only similar. Nonetheless it has to be questioned that the Citrangeremo would have been more fruitful with healthy roots because it got absolutely zero pollen and despite the many fruits only one highly polyembryonic seed that was not fully developed. That seems to be genetically determined. And I mean it was alive enough last year that it could grow a bit (not much) and bring the fruits to maturity.

I asked myself another question: Would the Citrangeremo ever have bloomed when it had remained healthy? I think no. I waited over ten year for blossoms and nothing happened. It only bloomed when it was ceriously ill and felt that it was to die. It seems to be really slow to bloom or blooms only as a huge tree.
I do not want to frustate those who want to grow it. Maybe the late fruiting is not that great a problem when somebody lives in a hot climate. I am optimistic that Citrangeremo will soon form a huge tree there as it is a fast growing plant.

I hope that I could save the variety. I made cuttings last year. The cutting did not root but did not suffer either. I made some grafts from these onto Poncirus. I think one at least should take. I have usually a very high rate of takes.

[Ahuacatl]

It sounds like you had some sort of root rot. The yellow foliage could be due to an accumulation of starch that had no where to go. This is what is seen in girdled limbs on citrus trees. Another note is that Eremocitrus is very susceptible to phytophthora.

[Till]

The Citrangeremo was grafted on Swingle Citrumelo which in principle does well on my somewhat loamy garden soil. It can be that the air was too moist during winter and some fungus entered the roots.
I have no own experience with the resistance of Citrangeremo roots. I have only read that all Australian species were imune to phytophthora. If that is true Citrangeremo is likely to be quite resistant against root rod when grown on its own roots. I can only tell that Fingerlime seedlings and also their hybrids with Ichang Papeda do well on their own roots. But Fingerlime is not E. glauca and both are not Citrangeremo.

[Ahuacatl]

Ok, I did not catch that it was a grafted tree.
What did the graft union look like? Was it swollen above the union?
 

[Till]

Nothing special. And bark was green. The trunk had only a many year old half-healed wound. But that cannot be the reason for the decline of the tree.

Sadly to say: I had a similar loss in a different greenhouse. A huge Calamondin tree suddently did not grow, got more flowers than usually turned yellow and died. It was grafted on Flying Dragon. In the same greenhouse as Citrangeremo was a well growing small Sudachi tree on Poncirus. The same picture as Citrangeremo: First flowers after the winter but no growth, then yellow leaves and dead. I could save Calamondin and Sudachi on Poncirus and C35, respectively. I Poncirus big Poncirus tree (Nikita and something similar) also declined but the reason is clear: Some kind of mildow in the bark at about 30cm above ground. The roots are still healthy. All that happened during winter.

I think there is something in the earth or in the air (obvious in winter mildow) but not a mouse. I would have observed that. The desease cannot be very infective as trees right besides the deceased ones still prosper.

I take it as fate or God's will. My space is very limited because I cannot cultivate Citrus plants unprotected inground and I produce new hybrids every year that will soon need space. I made a number of Calamondin hybrids. So it is ok that the Calamondin project is closed for some years. I realized that I do not necessarily need Sudachi for the next years. So it is ok, especially because the huge HRS899a bush right besides it needs more space to come to flowering size. I was very keen on Citrangeremo but realized at the end that it does not offer much to my breeding goals. So it is ok that it makes space for Poncirus seedlings that I once got through the forum and that should get very good fruits. I have plenty of seedlings of Nikita, supposedly many hybrids (Cicitranges). So it is ok that Nikita makes a pause for some years, especially because I need space for better Poncirus varieties (Poncirus+, PT #7 and others) and by now switched my hybridizing plans to Poncirus Till #1 which is better than Nikita. In a few year, my smaller Nikita trees will begin to flower, probably early enough for the next plans.

In earlier days I was very frustrated by any loss. But now that my collection contains better and better varieties (thanks to many kindly giving forum members) I begin not only to be happy for any fresh good growth but also for some losses. Yet, I still cannot totally give up a variety. It's a weakness perhaps of my character or perhaps wise as I do not yet know what I will need in the future. I cannot really kill a tree. So it is perhaps good that God does the brutal job as I really need space.