Here are a couple links to a rootstock test in Arizona: http://ag.arizona.edu/pubs/crops/az1051/az10519.html
http://ag.arizona.edu/pubs/crops/az1427/az1427-08b.pdf

They found Citrus volkameriana and Citrus macrophylla and rough lemon outperformed others in test with lemons.

There is also many stuff in the SP34 Puplication from the University of Florida "Rootstocks for Florida Citrus".
Usually those trials include only major rootstocks, but having very fine result datas and thus showing the difference in quality and fruit size of major florida Oranges.
So it is recommendable to read, but as long a my metor Dr. Wutscher once told me: "Do not pay to much regard on fertilizer and rootstock! It will have a less important effect to fruits grown on a plant grown in a container, as if the plant is grown in free soil!"
So and that's what I can only agree by my personal experiements on the windowsill: My plants on Volkamer do much better than on trifoliate orange, and in fruit quality, there is not realy a tasteable difference.

But the Arizone trial is very interesting.

@Millet:
Your right. I do not know, what Four Winds usually uses as rootstock, I guess it's the typical Flying Dragon because beside the Poncirus trifoliata x Citrange 'Troyer' stock, it's the only true dwarfing rootstock I know.
And infection with CEV was done on trial in Israel, with the success on getting trees the picker has to crouch in, as to pick upright, to small however and often inferior fruit quality. So CEV as natural dwarfing agent was abandoned, because the results were not realy promising, because nearly uncontrolable.
I can't get any plant from a Nursery, because the import restriction of the EU are very strikt. So what I have to do, is establishing local connections to US people, which root a cutting, if possible in a virus free area, and send it to me, as personal share. Here custum won't realy act, as it's no drug and they often do not consider the plant as harmfull or restriked, so I become little plants, as my Key Lime once.
but local Nurseries in the US need an import licicense, and that's impossible. And most of those Nurseries won't graft to my prefered rootstocks, and so I do not consider them as source.
But I am still looking for a rooted cutting of Stan McKenzies "Dancy" chance seedling, he once told me from, because that seems to fit for my conditions....

As I said, I believe Four Winds "True Dwarf's" rootstock is Cuban. As far as the published attributes of common rootstocks, much of that information, and much of the attributes, can be thrown out the window, when the rootstock is used in a container. Rootstocks in a container are a complete new ball game, and not much of the known qualities of an understock applies. My guess, is that more information is known about FD and Poncirus as a container stock then most. - Millet

Hi,

I asked many farmers around, get their opinions and even found few who already has Citrus macrophylla rootstock.They all agree that our city is not warm enough to use Citrus macrophylla. They noticed that even at 0C, Citrus macrophylla rootstocks have problem, they are not enough cold tolerant.Some lost their fruits, even their trees on Citrus macrophylla

Actually, my city is one of the hottest cities in the country, it is like hell in summer here, and it nevers nows in that city;
http://www.weather.com/outlook/travel/businesstraveler/local/TUXX0061?from=search_city

So, Citrus macrophylla is really not cold tolerant, we see 0C for 7-8 nights in winter, so I have to skip this option as rootstock.

Best,

In the mediterran basin Citrus macrophylla would realy not do well. It's one of the least cold tolerant rootstocks among all discused here, and as far as I know it is not used for ochard trees in the mediterran area.
But for budwood foundation plants and container plants, especially ornamental varieties, it's still in usage and can be found even in the mediterran.
Because of it's salt tolerance capacity it was considered for many close to the mediterran sea border set groves, but as reported, most of the trees do not deal well with the often occuring low temperatures.
Thus is was abandoned.
So the only replacement rootstock which made the run was Citrus volkameriana and ochards of Mandarines, especially Clementines in Morocco, Egypt and Tunesia have been established in the recent years.
Large Lemon groves were found on this stock in spain and areas of italy, because of high yields and large fruits. In Andalusia/Spain many ochard owners, like the well know Dittmeyer company, has many sweet orange planting on Citrus volkameriana, because of the high alkaline/calcerous, sandy, infertile soil.

But: Usually there is still no replace for Citrus aurantium in most plantings around in the mediterran basin areas, so it will here stay the number one rootstock used.

On Sunday after we got back home from the
misses grandson's Go Kart race in Atwater
there was a CGF private message that had
come in. Later on that evening I read it.

I am not in disagreement about using Trifoliate
rootstock for Kumquats. I did not write in this
thread that I felt Rough Lemon was a better rootstock
to use and then later saw (and this time it registered)
that the subject was C-35 compared to Sour Orange
to which I avoided the Orange altogether. Thought
sure someone would come back at me for referring
to Rough Lemon in that post then.

In a home garden or in a home landscape if I cannot
have a Fukushu or a Centennial on their own roots
I would prefer them to be on a Trifoliate hybrid
rootstock. I can understand why someone would
want to use Trifoliate orange and for them where
they are and they experience gradual cooling rather
than an abrupt cold instead that leads to a "quick"
freeze, I am not going to disagree with their choice.

I am in an area in which I am not seeing any real
advantage of using Flying Dragon as opposed to
the older Trifoliate orange but I do recognize
that other areas have had some good results
using Flying Dragon for container plants and
for in the ground plantings. I think it comes
down to personal preference in what we want
from the rootstock since people are more
intent to have plants come in that are budded,
some can be grafted still or they get wood and
either branch graft onto an established rootstock
parent plant or take those buds and put them onto
any old rootstock that is available and run with
those put together plants and then see how they
hold up. A 6-8 year trial of these plants in
containers and later planted in the ground is
not enough time to fully evaluate the rootstocks
ability to do well in a given area. Put 20 years
on those rootstocks and then we will have a
better idea as to how well a C-35 holds up to
in ground plantings compared to the rootstocks
that had been used for several years previous.

I think it may be to someone's benefit to get in
close tabs with Mr. Dillon at Four Winds and
go out to the nursery and let him tell you why
he does things a certain way. Find out what
rootstocks he used to use for the dwarf form
plants and learn what he still uses for the
semi-dwarf plants that he still carries.

Years ago even Willits & Newcomb had ads
in the California Citrograph whereby they
told of some of the rootstocks they were
using for their trees. Today what once was
a means to let people know who was using
what for their rootstocks has now become
almost an in house nursery trade secret in
that even when asked via an e-mail what they
are using for their Fukushu Kumquat or the
rootstocks they are using for their dwarf and
semi-dwarf Page Mandarins that a concise
answer is not forthcoming. We get no answer
from their web page and that is by design I
feel. We have to either see them in person
and get the scoop or if they know who we are
we can call them on the phone and ask them
but any more anyone that they do not know
is a potential threat as all it takes is one
unhappy, finger happy with an online keyboard,
person that lost a plant that can lead to a wildfire
of criticism in an online forum host and I've
seen it done in a forum format that I was once
a member of and now have no use whatsoever
for that "kid" forum format host web site.

If I am in the Arvin area any time soon I'll go
by there and see the W&N operation but I
may not be at liberty to openly divulge in a
forum format what I saw there or was told.
Fellow nurserymen or people that at one time
were involved in the wholesale side of the
nursery industry generally know, or they
used to, how to keep a trade secret. It is
old school practice that when someone
speaks out and tells what they should not
have told, they will not be told anything
more for a long while, so there is a fine
line to walk at times when dealing with
nurseries that are growing plants for in
ground commercial plantings, in more
recent years for landscapes, collector
enthusiasts and for home garden end
user consumers.

Jim