The Tropical Fruit Forum

Boris,
they give the Latin name here: https://insanehabitats.at/product/tyron-raubmilbe-gegen-milben-auf-weinreben-obstgehoelzen-1-pack-10-streifen-a-30-50-stk/ It is Typhlodromus pyri. You find a lot of pictures with google which are better than any description. Yes, I think "Typon" is some kind of marketing name or popular name.

I had them from Austria. From here: https://insanehabitats.at/product/tyron-raubmilbe-gegen-milben-auf-weinreben-obstgehoelzen-1-pack-10-streifen-a-30-50-stk/
They cost only 18 Euro now but are still sold only in winter. There are other firms that sell them in Europe but they are by far not as common as other predator mites. Some firms only sell to institutions or other firms. I had to google a while and found about five sellers in Europe. Not many.
I could imagine that you can order them from Europe when you live in the US, except the genius at the head of the goverment happen to be inclined to prefer hidden greatnesses of the American fauna for selling.

When nothing help we could try an experiment the next winter. They sell the mites in a dormant state hidden in pieces of felt. The mites naturally hide in bark or such things during winter. I could hang some extra pieces of cloth in my greenhoues before winter and send you some. It is only an experiment. I suppose that I do not have many mites as I do not see their prey. (There will be little rests of spider mites but unvisible. Last autumn I saw some on one plant but they are gone again.)

Or I could oder for you and send the mites to the US. They should survive that when they are dormant.

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.

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.

I also did my best yesterday to search for the right percentage of colchicin in the internet. There is not much information around and the amount of colchicin used varies from experiment to experiment and from species to species. But the amount in the bulb of Cholchicum autumnale seems to be sufficient to double the chromosome number.
I want to try the juice of Cholchicum in spring, not on Citrus but on growing buds of two Sorbus hybrids. I hope that I will have time enough and be successful. If so I am going to post it here.

Roses are a good example against my observation. But I think only seemlingly. There is the tendency in Roses to produce short fruiting wood. I am not an expert for Roses but I think the wild Roses first produce a long flowerless shot and then have flowers on short side shots in the following year. Cultivated forms can be different in that the differentiation between long twigs responsible for growths in lenght and short twigs responsible for flower formation is not so clear. Many cultivated forms only produce relatively short shots that are intermediate between both types and can carry flowers or not.
Roses are perhaps not the best example against my theory because they are more strubs than trees. And the whole Roseacea familiy is even a more difficult analogy as some members are trees, others strubs and some forbs. There are also intermediate forms and a development from one form to the other.

Regarding Citrus I admit that some madarinelike varieties and Kumquats produce flowers at the top of new growth, new growth that can be the very top of a tree. It would be interesting if that also happens with first flowers. I do not know the answer. I only suspect that a young seedling is strong growing and that the strongest growing twigs will not flower simply because they focus on new growth.

The difference between Poncirus and Mandarines is anatomically not so great I think: The habit of mandarines or kumquats to produce flowers at the top of new growth is perhaps the original state. Poncirus has then reduced the flowering wood to 1mm without leaves so that only flowers seem to be build. It is rare that the original construction plan shines through. Because the twig that carries the flowers is so extremly reduced in Poncirus (and some other citrus) Poncirus introduced an intermediate step: It first builds short side shots which then produce the flowering wood which in fact is more a bunch of flowers than a twig.

Ilya has just recently sent a fruit of Staruzu (5 Star x Yuzu) to me. It was as big as a big Clementine or small orange. It contained only a few seeds. Taste was sour and aromatic with a good proportion of bitterness, the kind of bitterness you know from grapefruits or Ichang Papeda. No internal oils. Very juicy. I am not a real friend of bitter fruits, yet I found it pretty good for lemonade or as a spice for cooking.

Welcome to the Forum, Rei! And thank you for the detailed report. It seems that our climate is quite similar. I live near Aachen (Aix-la-Chapelle) but around 500m above sea level. Your winter seems similar but summer are probably warmer. How does pure Poncirus do in your climate?

I had heard about the method earlier but it was good to have it described again with more detail. It could be something I should try.
It would be interesting for me, however, what the advantages of this method is as compared to just grafting young juvenile material into the crown of an older tree or to graft young seedlings on rootstocks that are about 1,5m high. I have very limited space but some bigger trees that I do not want to completely topgraft but would like to use part of them for accelerating fruit bearing of young hybrids.
According to my experience all seedlings - at least Poncirus and its hybrids - bloom at about 2m height. So I guess that height is what counts.

Fits my impression. The last cross was Sucrena x Ichang Papeda. The seedlings are to small to be fully evaluated. But some show clear signs of hybrid nature. Sucrena should be highly nucellar as all sweet oranges. But seedlings look different. Dunstan Citrumelo x Ichang Papeda also resulted in hybrids (one fruit, two hybrids).

Interesting the seedlings of Violetta! I did not hear about them before.

Regarding pollen, hmm, it is of cause difficult for a citrus enthusiast to avoid any pollen contamination whatsoever when he wants to write a letter to the US....

I have Limequat Tavares x Yuzu two seedlings. They are only 30cm high so far. Let's hope they will taste good. I have also Red Fingerlime x Ichang Papeda. The seedlings are only one year old but grow well so far. They look very similar to pure Fingerlime seedlings.

I find most theoretical considerations here quite reasonable. But perhaps we should just try. Thank you Lauta_hibrid that you took the first steps. Considerations about probabilities of success are good to remind us of the effort that might be needed but they remain highly speculative. A few years ago hardly anybody believed in the possibility of tasty Poncirus hybrids in the old citrus forum. Now we have already some and it has become silent about the skepticism. How much more can we hope in lemonlike hardy citrus?

Ichang Papeda is very sour but also bitter. When bitterness is not dominantly inherited (there seems to be hope) than a Lemon substitute is not far from possible on the basis of Ichang Papeda.

Opinions on Yuzu seem to greatly differ between Europeans and Americans. The reason may be that we Europeans have other types of Yuzu. My Yuzu allows you to make a very tasty lemonade. I do not view my Yuzu as a poor Lemon substitute but as a fruit the taste of which is perfect in itself that allows to make a lemonade that is equal to or better than Lemon lemonade. The only disadvantage is the many seeds.

My impression is that Pumelo is a good source for Lemon taste besides Lemons, as others have already noted. I think citrumelos should receive more focus in our brain storming. They have the poncirus taste that we don't want but also have a strong lemon taste.

I wonder why nobody wants to include Ilya's Ichangstars in his or her breeding plan. They are probably hardier than Swingle 5 Star and Ichang Papeda and have a better taste than both.

Has somebody tasted Citrumelo x Yuzu? There is such a cross in Frensh nurseries and is much praised for its taste. And Ilya has also produced such crosses. Perhaps a good Lemon substitute already exists.

Maybe I have overlooked something but I think nobody has spend a though to the taste of the peel. For me, Lemon peel tastes very good or at least interesting. A Lemon substitute should at best have an edible peel. It is alluring to think of Kumquat as a source for breeding now. But I have Buddhas Hand x Kumquat and can tell that its peel is extremly thin and a bit bitter. It seems to me that crosses between Kumquat and Citrus have always a thin peel. Somebody who wants to breed for thick edible peel should therefore better think of alternatives to Kumquat: simply citron, Haruka, Keraji mandarine (peppery peel!) or better citrumelos. The peel of Poncirus hybrids usually tastes horrible. But Staraji has peel that is ok and I have a hybrid that is falsely sold as "Rusk" by Oscar Tintori nursery that has a peel that tastes like citrus peel. So it seems possible that the horrible peel taste of Poncirus hybrids can be outbred. So breeding experiments with the goal of edible peel may include citrumelos. The thick peel of pumelos seems to be easily passed on to its offspring while there is hope that the taste improves.

As I mentioned elesewhere, hardiness is relative. It is not only important how may digits below freezing a plant can withstand but also how resistant it is to late frost in spring. To those fearing late frost I would recommend thinking about Yuzu. It is sometimes less susceptible to late frost than Poncirus and my Yuzu x Poncirus grows as late in spring as pure Yuzu.

Pure Poncirus has different tastes. Some varieties have mainly a Lemon taste while others also have stronger orange notes. Good Poncirus types are already hardy substitutes for Lemons as long as you are only interested in making lemonade from them. (Let the juice stand in a glas for some hours and throw away the bottom fraction.)