While a lot of “average customers” and novices indeed have no or very little knowledge/understanding of rootstocks, most experience fruit growers on this forum are very much aware of the rootstock’s role, and you can find here innumerable topics discussing rootstocks.
While existing academic studies (mentioned by @Richard) provide a lot of very useful information, soil characteristics can have a very significant impact on a rootstock’s performance, and therefore people living a few miles from each other can observe very different results. Knowing your climate and your soil and being guided by academic studies and other growers’ observations but most and foremost by your own experiences through trial and error are necessary for choosing rootstocks and varieties that will perform well for you.
Reading a wikipedia article is useful for somebody who is just starting with fruit trees, but for experienced users it’s just a compilations of truisms and old news. In the wikipedia article that you have linked, the very first statement: “Pears are usually grafted onto quince rootstocks” is outdated. This was true for Europe in an era before fireblight (brought from the US in 1970s) started to be a factor, but things are rapidly changing, and growers in Europe are transitioning to the OHxF series rootstocks and particular selections of P. calleryana and especially P. betulifolia. This is not true for the US for a very long time, and here the transition from quince to fireblight-resistant and/or hardier rootstocks happened much earlier.
It might no longer be universally true. But it’s definitely not outdated. I’m in a country that exports a lot of pears. And practically all of those are grown on quince rootstock.
There are also selections of fruiting quince selected for fire blight resistance. Might not have enough to survive across the pond. But they make quince culture possible in places where “old” cultivars where no longer viable.
Currently I’m not aware of a pyrus rootstock that reaches quince yield efficiencies in Europe. Until we have that, and in a sufficiently dwarfing size + it not negatively affecting fruit size. I don’t expect it to change significantly any time soon.
Pyrodwarf for example is a pyrus rootstock from Germany. But not widely used. Since it’s not dwarfing enough. And not productive enough.
It’s all relative. Since the size of the rootstock is not always the same.
It’s always a combination of soil/diseases/culture/rootstock/variety that matters. (and probably a few other things i forgot)
Some rootstocks are roughly equal size in 1 climate and different in another.
And how about the differences between species?
M9 is considered dwarf for apples. But compare a M9 apple tree to a Gisella 5 cherry when fully grown. And 1 of those would clearly dwarf the other.
However if you graft a bramly or very vigorous apple on a M9, that will also change it’s mature size significantly.
I know in cherry culture they talk about rootstocks and how they affect the fruit a lot. Mostly how it affects size, since larger cherry’s fetch a premium.
There is a difference for example between Krymsk 5,6,7 and Gisela 5,6,12
They can be roughly equal size. But the Gisela’s tend to be more precocious, and thus can overset when combined with productive or self fertile variety’s. Leading to smaller fruit size. I can’t find the source. But remember reading an university document. Where they talked about wanting different sizes of cherry rootstock, and a choice between precocity in each size bracket. To match to the needs of the cultivar (scion)
these document might be of interest. I found them very informative. Gives you a insight into how rootstocks are developed. And what the developers value. (i would want a different plant from their trial than they released) But they select for market demands, where i select for hobby growing…
According to recent studies in Israel, selected strains of P. betulifolia produced the highest cumulative yields per tree and the highest cumulative yield of large fruit, way better than quince. P. betulifolia is obviously not dwarfing.
yield per tree matters little here. Here yield per hectare is important. Due to high land prices. Also picking efficiency is important due to high labor costs. Both those things tend to favor smaller quince rootstocks.
Our old seedling apple rootstocks also had higher yield per tree than M9 for example. But they are practically extinct in the commercial culture.
Quince rootstock has obvious weaknesses though. (does poorly on alkaline soil (like in the paper you mentioned). And it can be more disease prone depending on diseases/climate. Also the smaller size can both be an advantage (in intensive culture) or an disadvantage (in culture without irrigation for example)
I expect the Pyrus rootstocks to help grown pears in soils the quince rootstocks dislike in the EU. But i think it will be a few decades (if at all) before there are more hectares of pear orchard on pyrus rootstock than quince.
a lot can change though. For example fruit picking or pruning robots might change the game. If they can pick high fruit. More vigorous rootstocks might become more common again. Due to their lower culture needs.
Cherries are a big tree in general. From my understanding most commercial cold area fruit trees top out at 25-30 feet on standard size rootstock (peaches, apricots, pears, plums, apples, IE mulberry does but is a semi dwarf tree). Meanwhile a standard sized cherry is often expected to reach something like 35+ feet on rootstock like Mazzard. Gisela 3 is more of an equal comparison I feel for a m9 apple tree. Only Nursery I have found selling cherry trees on Gisela 3 is Raintree and those sell out pretty quickly. My cherries have not fruited yet though. I will be comparing trees on Newroot-1, malhalab and Mazzard I believe. The suckering on my Mazzard is diffidently way worse than on my Newroot-1 rootstocks so I can compare that. In regards to pear rootstocks I see very few selling on quince here in the USA. Some people question quince rootstock hardiness here in the USA. The most common dwarfing pear rootstocks here are OHXF 333 and OHXF 87. The most common standard size pear rootstocks are callery and BET. OHXF 87 is known for making more production on the tree similar to your quince piece.
Another thing to add about rootstocks is I have bought from places specifically for specific rootstocks like pears and some places don’t even send the trees with the rootstock they advertise. I bought a Comice and Warren Pear from Nature Hills Nursery. Something you will notice is their Comice and Warren pears both state Callery rootstock but one states it gets 30 feet with the Comice and the Warren pear states it only gets 12-18 feet. I paid a fortune on the pear trees hoping for that standard size rootstock and the Warren pear came on OHXF 333 and the Comice either came on BET or the promised Callery but I would have to check the tag. In other words I don’t even thing some nursery are paying attention to rootstock.
Burnt Ridge Nursery has root stock items listed, and USDA ARS has also various listings for apples (Cornell) and pear(NW-Portland?) and I believe Grandpa also. It can make an ENORMOUS difference-for instance wet vs dry, pH, etc. differences and some disease resistance. For instance-what did well in Downriver Detroit didn’t do well in central Ohio on pH 5.5, subsoil when I first moved and planted some fruit trees I grew up with. The best bet is (1) weather pattern where tree is going (2) pH and good soil analysis and (3) critters and diseases locally-plant diversity rather than what everyone else has. I grabbed Trees of Antiquity, Raintree and BUrnt Ridge and NOTHING that local nurseries had and then espalier for better wind circulation for my stuff. Naila-USDA retiree
