The image says "artist rendering", it is unclear to me whether this tree exists today or if it's an ongoing project that expects to be finished some time in the future (40 successful grafts would take a number of years to do I imagine).
While it's an ongoing project producing them, as of the 2015 article "Today, there are 18 of these wondrous trees across the country, with three more being planted this spring in Illinois, Michigan and California. Seven are located in New York—including the very first Tree of 40 Fruit that’s still on the Syracuse campus—and six more are in a small grove in Portland, Maine."
These are an awful lot of work. I've got a couple of multigraft trees, with just 3 varieties (apples) on each, but wouldn't want anymore. Some varieties are much more vigorous than others, so they require a lot more care and effort with pruning and training.
Pest control, irrigation, picking are also much more complicated, as different varieties ripen at different times (often over many months).
As I understand it there's no productivity gains either, in terms of volume of produce per unit of (land) area. Most commercial growers have moved / are moving towards upright trees, with dense plantings (1m spacing or less), as it maximises the labour, off-farm inputs, and management costs versus saleable produce.
Doesn't look as pretty as the imagined idyll, but little of industrial agriculture does.
It’s fun for small yards. I have a few plum and pluot multigrain. As you suggest it’s usually a game of wack-a-mole balancing the healthy vigorous variety with the slow one. The benefit is different fruit varieties at different times of the year.
I think even in small yards it's better to have a couple of upright trees. For pomes (apples, pears etc) in Australia we're seeing most nurseries now sell these on M27 (tiny footprint - will grow to about the size of a human), or M9 (bit bigger but still quite dwarfed).
3 x M27 grafted apples will take up the same (or less) space than a single standard multi-graft tree, but be easier to manage, be more resilient, while still giving you the longer harvest season & variety options.
As the linked page stated, though, the point is neither productivity nor commercial agronomics, the point is preservation of heirloom varieties that are precisely not interesting to commercial growers. I think this is a very important effort since it preserves genetic lines that may in the future turn out to once again be interesting as climate change makes new and unanticipated demands on food growing. That's not to say that we'll use those old varieties unchanged, rather that they may contribute genetics in the development of new strains.
Brogdale [1] in the UK has ~2400 apple, ~500 pear, ~300 cherry, and a huge range of other edibles -- a fascinating place to walk around if you're ever in the area. But none of them are multi-grafted. Each apple variety has two physical specimens -- adjacent to each other, on semi-dwarfing stock, and they re-graft and relocate every ten years or so, IIRC.
One of the researchers there told me that in the UK there used to be a known range of close to 10,000 unique apple varieties, but many are now simply lost in time.
In Australia we've got a much smaller range available -- in the order of a few hundred I think -- but I don't believe anyone trying to maintain a collection is using (let alone relying on) multiple grafts on the same plant.
Fascinating -- thank you. I was not aware of this collection. I'd surmise that careful attention also has to be paid to cross-pollination requirements. Many fruit trees require a compatible pollinator, frequently of a different variety than itself, so it can get to be a real challenge. I can't imagine trying to track pollination compatibilities across that many varieties.
> the point is preservation of heirloom varieties that are precisely not interesting to commercial growers
The problem is that is not realist. This is definitely NOT how we will preserve heirloom varieties. Each variety needs their own tree not a stem. Trees discard its stems all the time so in 5 years most ot your varietes will dissapear. Has happened before with old cherries.
The idea would be like trying to save dog breeds putting a collection of dogs from all breeds (shih tzus, mastiffs, chihuahuas and great danes) in the same room and competing for the same food
Even though grafting does not increase crop yield, it does reduce time to first harvest and improve resistance to certain kinds of pests and plant diseases, particularly at the root.
In commerical wine production, most if not all vineyards have grafted the wine plants into rootstock of other plants (roses iirc) that have more resilient roots.
Some fruit trees are produced similarly, using a fast growing and resilient rootstock and grafting the fruit bearing branches on it.
And when buying new young trees to my garden (from a commercial supplier), I noticed that all of them look like grafts.
Grafting may well increase crop yield just because it increases vigour, and reduces disease & stress vectors, for the plant. I didn't intend to suggest grafting is bad -- it's clearly a great thing to do. All ~25 of my heirloom apple, peach, and pear varieties are grafted. And yes, I doubt you can find fruit trees in a nursery that aren't grafted.
I was suggesting that multi-grafted trees are more bother than multiple single-grafted trees.
One of the points of grafting a familiar cocktail tree is to have different varieties rippen at different times, assuring the longest fruit season possible.
Again, the problem is that it's often easier to simply have different varieties on different trees, given those trees can be on highly-dwarfing rootstocks, so that they take up a similar space as a 'cocktail tree' with multiple grafts.
Multiple trees also turn out to be a lot easier to manage -- you can prune them all the same size & shape, for starters, rather than having to track which branches belong to which variety and try to coax the slower growing specimens along, while being extra savage with the more vigorous varieties.
This would be a good way to do it, but extra-dwarf rootstocks are delicate: Poor root systems, poor disease resistance, poor wind resistance, will not tolerate dry places or chalk, and are less vigorous than fruit varieties affecting to the graft point. They typically have much shorter lives.
And not all fruits have this kind of rootstocks available.
Sometimes, in small places, a big tree grafted with tree or four varieties is the right thing to do. It depends on the type of fruit, the type of soil and the space available.
[Cocktail tree is a common denomination for this kind of trees, specially used in Citrus. I have one, grafted by me]
Less vigorous root system, but that's how it dwarfs the plant -- not sure if they're less resistant to disease (I expect this is one of things they select for while breeding). Definitely these types (m9 ,m27) and similar need staking the entire life of the plant.
Cocktail tree is something I've only heard in Australia, and only from some small subset of nurseries -- it's also commonly used in Spain then? A cocktail plant for me would normally be something like Mentha nemorosa (also challenging to find in Australia).
A friend had a 3-way citrus, which did breathtakingly poorly for them, for the same reason my two (3-way pear, and a 3-way apple) -- a single dominant variety and two much less vigorous grafts. My two are now at least 25 years old, and still present more maintenance challenges than some decent stakes, soil maintenance & mulching.
This reminds me of the Library Grape from Anathem:
"The library grape had been sequenced by the avout of the Concent of the Lower Vrone in the days before the Second Sack. Every cell carried in its nucleus the genetic sequences, not just of a single species, but of every naturally occurring species of grape that the Vrone avout has ever heard of -- and if those people hadn't heard of a grape, it wasn't worth knowing about. In addition, it carried excerpts from the genetic sequences of thousands of different berries, fruits, flowers, and herbs: just those snatches of data that, when invoked by the biochemical messaging system of the host cell, produced flavorful molecules. Each nucleus was an archive, vaster than the Great Library of Baz, storing codes for shaping almost every molecule nature had ever produced that left an impression on the human olfactory system.
A given vine could not express all of those genes at once -- it could not be a hundred different species of grape at the same time -- so it "decided" which of those genes to express -- what grape to be, and what flavors to borrow -- based on some impossibly murky and ambiguous data-gathering and decision-making process that the Vrone avout had hand-coded into its proteins. No nuance of the sun, soil, weather, or wind was too subtle for the library grape to take into account. Nothing that the cultivator did, or failed to do, went undetected or failed to have consequences in the flavor of the juice. The library grape was legendary for its skill in penetrating the subterfuges of winemakers who were so arrogant as to believe they could trick it into being the same grape two seasons in a row."
When she was younger, my mother owned a house with an apple tree that produced six varieties.
I understand this can also be done with citrus and grapes, as well. Pretty fascinating that their immune systems don't cross react, I think I remember that plants mostly use innate rather than active immunity.
This is a Prunus tree most probably. Could bear different varieties of cherries, plums, mirabelles, damsons, gages, peaches, almonds, plumcots, and pluots. All at the same time.
You can have also a tree with 40 varieties of apples and a similar good display in spring.
It would need some watching and effort to manage it at long term (avoid vigorous stems killing the other fruits, avoid virus spreading) but is possible, yep. With accurate pruning could produce around 1,5 Kg of each fruit at year or so at ten years, plus a really nice display of white and pink flowers each spring.
It must be noted also that either the tree is specifically created by somebody that knows what is doing, or can ve very dissapointing. Try this with Citrus would be dangerous for example. You can't have plums and apples or pears in the same tree. No matter how many peach varieties you graft, you can't have peaches if your climate is not rigth for it, so this will work fine in a computer, but you'll need to be much more astute and observant to translate this succesfully to real life.
So I've got an ornamental plum that doesn't really fruit. I've read it can still be used just fine for grafts.
Does anyone have good resources on how to get started grafting to do this? I have access to peach, apricot, cherry, apple and nectarine trees as the donor grafts.
I don't think an apple root stock would work as its not closely related.
Additionally, theres a technique called budding[1] where you just graft individual buds. This has the advantage of maintaining the habit and structural integrity of the root stock.
Haven't got any good resources for you though, sorry.
Edit: googling answered my own question, this is indeed an ongoing project: https://www.smithsonianmag.com/innovation/a-tree-grows-40-di...