I have read, on several occasions, that some mandarins (not Satsuma) and trifoliate were not graft compatible. Below is a link to one place I have read this. I would consider the author to be an expert on the subject.

http://edis.ifas.ufl.edu/HS123

Others sometime recommend trifoliate as a rootstock without making note of this. Does anyone have a definitive answer to this question?

It says that graft incompatible with only some mandarin hybrids.

Sometimes these experiences or observations should be taken as notes, not really etched in stones. One has to take the context of such experiences. For example, if your aim is to produce bigger trees, then the dwarfing effect of the root stock and scion combo is not the desired effect and so would be considered as incompatible for the desired effect. As hobbyists we have tremendously diverse objectives.

There are also times that based on your growing conditions, some scionwood would not be "compatible" but when tried in other areas they would be compatible. The reverse could be true. For example, you would have more graft failures with potted plants than the plants in the inground. I've had more failures with satsumas than other cultivars, but repeated grafting at different times, made those same cultivars graft successfully.

If the grafts are really proven by yourself to be incompatible directly with a rootstock in your area, then graft something else to it, perhaps some oranges and then graft the mandarins over those oranges the next season.

That is true Laaz. I have a more general concept in mind when referring to incompatibilities and not only bud union, and I am slower in typing than thinking so could not explain my own context.

It was not clear also about the circumstances of such bud union incompatibilities. When did they do it for example, and have they tried redoing it several times through the season? Sometimes it could be initially incompatible due to the not so much sap and juice in the juvenile rootstock, but later on can be compatible. Sometimes the reverse is true. And also it could be that it is compatible in the short term, but not in the long term and the branch either falls off or wither away. Does this also mean budding only? Can other techniques be more successful such as cleft or bark grafting?

When all else fails, one can always use interstem approach (graft something that is compatible to both stock and scion) like I mentioned earlier.

Also some of the older concepts were due to viral disease, rather than incompatabilities. At one time, it was said that Satsumas could not be budded to Sour orange. Then it was discovered that the satsumas all carried a severe strain of tristeza virus. Once that was removed, the grafts worked perfectly well.

I believe the incompatibility referred to is that of trifoliate and certain mandarins to form lasting unions, but the material I have read so far doesn't say when failure occurs, and what varieties of mandarins are affected. I guess my concern is that people in cooler areas are given the impression that, for them, trifoliate is the rootstock of choice, but it appears that may not always be the case. It may be that you could make such a graft, only to have it fail years later. If so, it would be good to know which combinations work, and which don't, so as to avoid such a disappointment.

There may not be much information concerning this simply because there is a wide choice of rootstocks in commercial citrus growing regions.

I have read that there are instances with other fruits where bud union failure may occur years later, but in most cases those incompatibilities are well known.

Ned

I dug around a little on the web a little and could find nothing of much help. I did come across this website, which recommends tri for Alabama. I didn't see anything about inconpatibility. I appreciate the input - thanks.


http://www.aces.edu/pubs/docs/A/ANR-0603/

Also Ned, there are symptoms of decline that sometimes unavoidable as some of the trees tend to prune themselves off on their own, deciding which branch to prune off and those will shrivel turn brown and die off. These are naturally occuring. Check your mature trees, you will have them. And since I have 50 cultivars to one tree and I can see signs of start of wilting before the prune off, I immediately take out budwoods from affected branches and regraft them to the more vigorous branches. The constant regrafting will at some point stabilize and I don't move them anymore, and it keeps the tree well balanced. In effect, I have not yet observed any long term incompatibilities as I move my grafts around and keep my cultivar collection.

Yes Joe, I am aware of the dieback problem with small branches and twigs. This is more prevelant in some citrus than others.

I found the following article about rootstocks for Satsuma rootstocks interesting:

http://cekern.ucdavis.edu/Custom_Program143/5135.DOC

Some where in california a study was run on carrizo and satsuma. The way I understood the article about 15 years was the life on this combination. The reason stated was that carrizo was so vigorous the cambium was eventually shut off.

Buddingman, This may be the article you are referring to. I ran across it last night.

http://cekern.ucdavis.edu/Custom_Program143/5135.DOC

Ned