I don't know for sure; but I do know that Macrophylla is incompatible. Not many citrus or citrus rootstock do well in alkaline soil; can you amend it with soil sulfur to lower the pH? I have a long standing goal of creating a LOT of Kaffir limes. Most in the world and the best of course are grown from seed; but once I have a reasonable population for budwood harvesting, I can produce them faster by grafting... viable seeds are hard to source and when you can get them, they grow very slowly. The limited research I have done indicates the best rootstock for grafting would be some sort of lime.... first trial for me will be with hybrid Persian lime, mostly because it is available here.

Nik,

If you find a good answer, please let me know, as I need to find the answer in the next 2 years.

hmmm.. maybe a sandwich method would be appropriate for planting in the ground. Some lime on appropriate stock and then the KL on top of it..

UCR lists for KL

Rootstocks of accession: CRC 1449 Citremon, Yuma Ponderosa lemon

YPL appears to be the same as Cuban Shaddock

I might try budding it to Volkameriana and Sour Orange as these are readily available to me. SO is the best rootstock for our soils if it were not for CVT (amd Mal Nero)..

Next time I am at my local nursery I will ask what they use for hystrix.

Interesting that macrophylla is not compatible as it is also a papeda... though looking now I guess a citron x papeda hybrid.

Lots of things are not compatible with Volk... and those that they think are compatible... who knows?? The rootstock is too new to know for sure what will be the long term effects. I doubt very much that YPL is the same as Cuban Shaddock, which is a pomelo, while YPL is a citron hybrid. Personally I would not put much stock in what UCR says; most of what they have, what they "know", and what they say was just told to them by someone else. As an example, they tell you that the Meyer lemon is a thornless variety; I have 35,000 trees that say they are wrong. If I were going to do a trial... and trial is what it would have to be, as I can find no credible source for KL compatibility... I would start with a native lime of some sort, preferrably a vigorous grower. In a year or so, I will begin some trials of my own; so that in 2 years, when I have enough budwood, I will not still be stumbling around in the dark.

Volkameriana is used for lemons over here as a substitute for the traditional SO rootstock.

Do not confuse YPL with PL..

Bad,

I brought KL budwood from California; and my grafting guru got only one out of 25 buds; and that one is alive after 3 years, but barely grows at all. I suffered with that; because it not only cost me 4 years in my goal; but also because I love Mac... it is readily available here and is soooo resistant and aggressive.

Hey John, I know the feeling experimenting with grafting and having failures. Certainly a challenge working with uncommon varieties and trying to find what works. I will do some more research on hystrix rootstock combos.

While we are on the rootstock compatibility and characteristics topic this chart is pretty good...

http://ucanr.edu/sites/ucceventura/files/57694.pdf

Obviously lot of research is done on the topic but it's usually concentrated on the more common varieties.

Hey Nik, I just noticed that Cleopatra Mandarin and Rangpur Lime appear to perform well as rootstocks on Calcareous/Alkaline soils. Rangpur would be worth researching compatibility with Hystrix I think.

bad,

I am not expert in this but I believe that NO citrus performs well in calcareous soil. I have more than a little personal experience to support that. It may be the only soil that will not support citrus.. In my world I will not accept an associate grower who has calcareous soil; but I have associate growers who have purchased other land in order to be growers. BTW, if ANYONE has any insider information on rootstocks for grafting to Kaffir limes, if you share it with me you will become a lifelong friend of Mayan Meyer Lemons, a distinction shared by few

johnmerr,

If NO citrus performed well in calcareous soils, the Med citrus industry would not exist.. On a smaller scale, my citrus garden would not exist. Which proves you're pretty off the mark here.. What IS true is that the first criterion for selecting stocks is tolerance for the soil conditions since many of them do not perform well. Sour orange, many citrumelos, citranges and tangelos plus volk perform well in calcareous soil. SO was and still is the most common but it is being replaced commercially due to CVT (which was isolated here in 2000 imported from Spain thanks to our commerce friendly EU laws...). SO is extremely tolerant of calcareous and saline soils and water and very friendly to all sorts of commercial citrus scions. There maybe others which are not used commercially for other reasons (eg. subsceptibility to local diseases). Rangpur, for example, looked promising but is subsceptible to mal nero fungus. Having said this, ammonium sulfate IS our friend here..

I don't expect KL to be tolerant of our soils but one never knows. I might grow a few seedlings and test them in ground. Up to now my potted KLs have proved very tolerant of our hard alkaline water, that's all I can say.

Nik,

I defer to your greater knowledge/experience; or perhaps we just have a different definition of calcareous. Anyway, to my knowledge in Guatemala there are zero citrus growing in what we call calcareous soils.