The Tropical Fruit Forum

It is very challenging to multigraft an avocado tree, no matter how much pinching you do on the vigorous branches, the tree is just too likely to focus energies on the most vigorous branches, or push new sprouts from the base. I have pretty high success rates with late spring and late summer single-variety grafts here in Seattle (but I'm colder than you). But any time I try to build a multigraft tree I'll be lucky to get 50% takes after the initial set of grafts because you cannot properly force the grafts once you have other grafts on the tree that you want to keep. My worst success rates are in winter or early spring, it seems that it's just too cold here and the trees are more likely to abort the grafted stem than form callus.

Is there some reason you want to go the multigraft route? Space constraints or something? I've decided 2 varieties is the most I'll do for outdoor trees, anything more is not worth it other than on my greenhouse trees (space constraints indoors).  For 2-variety trees I recommend doing at least 2 grafts of each variety on the same tree and then if you get more than one to take of the same variety you can remove the weaker one(s).

If I want to also test the rootstock, I'll later allow a rootstock branch to grow, once grafts are established. Brad correctly schooled me on not letting rootstock branches remain at the same time as the initial graft, as that greatly increases the chance the graft will be aborted.

Interestingly, the leaves look trifoliate. The seeds were all monoembryonic and the only other citrus I had flowering was a lime, not anything with trifoliate ancestry. This makes me assume that this is not a chimera but rather an actual hybrid.

I've seen examples of fuzzy kiwi grown in "tree form" where it is trained up a single tall post and then allowed to hang down, similar to the way dragonfruit is usually grown commercially. I'd guess it requires a fairly diligent pruning regimen.

I don't think it'll do well in pots or kept short, but a single tall pole is a pretty small footprint compared to a whole trellis.

Looks like some combination of root rot and freeze and/or sun damage? What size is the pot? By 2 years from seed I'm usually potting mine up to a minimum of 15 gal or (preferably) planting in the ground. They can be hard to keep happy in a container, especially if it's not big enough.

Can you take a few photos of your leaves, does it look just like the photo I posted ?

I had posted a photo in that thread before:

https://tropicalfruitforum.com/index.php?topic=43492.msg513194#msg513194

The leaves tend to turn sorta fall colors in the fall but mostly don't drop off until spring when the new growth starts. I'm also trying to get some cuttings of it on their own roots this spring.

drymifolia, maybe UCR/CCPP gave you a wrong scion wood. I had that a few times, the fruit didn't look at their data sheet photo. I just purchased their Winters Seedless Lemon a few years ago and the fruits I have been getting isn't the shape of any of my other 8 lemon varieties. I hope it is seedless since last year it had seeds. My seedless Lisbon lemon has no seeds but not this new one, VI -909.

No, I think it looks like the right fruit, and the leaves match. I mean it definitely tasted bad, but just very sour and somewhat bitter, it tasted much better than the few trifoliate fruit I've ventured to lick before.

That was my review about a year ago, the fruit was terrible, I know a few others that grow it and said the same.

Here's the old post, my fruits were fully ripe, orange outside.

https://tropicalfruitforum.com/index.php?topic=43492.msg513242#msg513242

I wonder if it gets worse as it ripens then. Mine was palatable enough that I drank the entire few ounces of juice and I feel like it would make a good sweetened glaze or maybe lemonade. It was bitter, but not more bitter than most grapefruit, and it was sour, but no more than a lime or lemon. No other off flavors to speak of.

I got this one from CCPP a couple years ago and last season I had the first flower (just one) which set a fruit. It got blown off (prematurely, I think) by a wind storm last night.





I had heard from the UC person that it is horrible tasting, but I juiced it and the juice wasn't that terrible. Tasted somewhere on the lemon to grapefruit spectrum, none of that weird trifoliate funk, but you'd have to sweeten it a lot (or hope it gets a lot more sweet when more ripe) before anyone would label it enjoyable.

The seeds have an interesting distinctive reddish patch on the bottom end:



Here's the UC accession description:

https://citrusvariety.ucr.edu/crc3881

2031 is the earliest you can hope to get it legally and they will probably try to keep it under lock and key even longer than the expiration of the patent:

https://patents.google.com/patent/US20130055476P1/en

Tree size, not age, is what triggers a seedling avocado tree to begin flowering. That tree is too small. You'll need to pot it up to a larger pot and try to carefully root prune any girdling roots when you do that. Most avocado seedlings will fruit when they reach about 3 to 5 meters in height, but that's assuming normal healthy branches full of leaves. And some trees never flower.

As far as where to get scionwood in Switzerland, there's a flourishing avocado grove on a lakeside near Locarno, with many grafted varieties and maybe a few seedlings too. Maybe the person organizing that would share scionwood.

Are those seedlings outside with no protection? They are looking pretty good for mid 20s F

I haven't protected any of my in-ground trees yet this winter. Here's a photo from this morning (though it was actually not particularly cold this morning, just snowy):



The largest tree in bottom-right is a seedling of Mexicola Grande, the smaller trees in the background are (left to right) seedlings of Del Rio, Aravaipa, Mexicola, and Royal-Wright (that one is likely R-W x Duke). They've been in the ground for a few years but keep getting knocked back to the soil line when it gets down around 16°F. So far this winter with a low of 25.7°F (and a few other nearly as cold) they have some leaf damage but are otherwise doing well.

I have no idea what I was sold 40 seeds of but the leaves have no anise smell, I know poncho doesn't have smell.

I believe you're confusing Del Rio with Poncho/Pancho. My Poncho has a strong scent, but Del Rio (which I got from Craig Hepworth) has almost no scent. I've started dozens of seedlings of Del Rio and often the seedlings have no scent either but sometimes they do (maybe pollen parent was a variety with more scent, Craig grows many other varieties).

I saw a Facebook post of 29 varieties exposed to 21F the results were pretty surprising.

I'm not on Facebook and don't click on fb links, but if that was Ken in Arizona then I'm in touch with him periodically, and keep in mind that his tree is infected with the sunblotch viroid (ASBVd), which some varieties are much more susceptible to than others, and that might explain some of the unexpected results. Cultivars already weakened by the viroid might show unexpected freeze damage.

Only about 5-10% of the seedlings from cold hardy avocados are similarly cold hardy like the parents. Most of them have damage in the 25-28 degree range. That’s why we graft. I do encourage planting seedlings so we get new varieties.

What is your source for this claim? I've grown many hundreds of hardy seedlings and I'd say their hardiness is a bell curve roughly centered on the parents' hardiness (especially where likely pollen parent is also known).

Yes I plan on using them as rootstock. I know the Florida fruit geek uses poncho. He doesn't ship though and have tried to get in touch with him several times.

Craig uses Del Rio mostly, not Poncho (I don't even know if he grows Poncho). He will not ship trees, but he did ship me a box of seeds in fall 2023, and I had a family member in his area pick up trees from him and send me scionwood a few years ago as well, so that's how I acquired Del Rio.

Brokaw told me a couple years ago that they will never sell ungrafted rootstocks, you have to instead order grafted trees on those rootstocks. I wanted to buy Toro Canyon, though, not the ones you list there. When they said they had to be grafted and ordered 2 years in advance, I asked for a quote for local pickup for 20 trees, Mexicola Grande grafted on Toro Canyon. Here's the email they sent me:

For Mexicola Grande on Toro Canyon that would be a “special order” for California only at 100 trees (3.5 gallon sleeves only- see below for our field trees) minimum. $42.80 each paid in full prior to propagating.

We do not sell ungrafted rootstock or scions as we use all of our rootstock for our production.

Minimum order of $4,280.00 just to get a clonal rootstock that I only really wanted a few trees, so I haven't tried to order from them again.

I've also heard the same about Mentor Grafting being tossed aside as a dead end with no usefulness. At first I was thinking that's not how genetics works but maybe how Epigenetics work. It turns out Horizontal Gene Transfer seems to be very real.
 
I wonder if the consensus only tested this theory on mature plants grafted on Mature Plants? I legit think this is why it's not commonplace, no one does it with Young Hybridized highly plastid Offspring, most are working with mature highly stabilized non-plastid plants. It's very recent these Chinese Researchers have shown there is more to it, the consensus spread is much slower than I realized.

As you look into to, look for scientific papers on Ivan Michurin's work, a lot of the Chinese Researchers have tested & proven his theories.
Report back any cool things you find, I love Learning!

I don't have the time for a deep dive at the moment, but from a lunch break surface skim, I did indeed see discussions of recent Chinese research, though mostly in the context of "look graft hybridization is a thing that can happen," not specifically about it proving anything about mentor grafting helping to enable sexual hybridization, and there have been accusations of falsified data in some of those Chinese studies. I just have a strong suspicion that it is not a practical means to enable sexual hybridization of species that are not otherwise genetically compatible, even if you might get a 1 in a billion lucky gene transfer that fixes the incompatibility.

Since Diploid x tetraploid often forms sterile triploids, what happens if you combine mix Diploid & tetraploid pollen to pollinate the Sterile triploid again? Will it fail to set fruit, make seedless fruit or be sterlie again in the next generation?

Triploids often fail to flower, have flowers incapable of forming fruit, or more rarely form seedless fruit. Because the seed parent is incapable of producing viable offspring, no amount of pollen trickery will fix that problem. I've also been unable to find any research paper about any triploid Diospyros species or hybrid ever being created, so I suspect that diploid x tetraploid is simply entirely incompatible in this genus.

The only way to solve incompatible Chromosome numbers is to have one double so it's an even number? I've heard it's the odd number ploidy that's the hard part for breeders but I'm not sure why?

Odd numbers are problematic because each parent generally donates half their chromosomes to the offspring, so you can't get half of 3 or 5. But it's not entirely that clear-cut, occasionally the odd ploidy gets paired with a mutation that solves that problem by doubling something or fusing something.

Also it seems like higher odd ploidies have fewer problems than lower odd ploidies (some papers discuss nonaploid kaki cultivars and I don't remember any mention of them being sterile). Nonaploid can happen with hexaploid x hexaploid where one of them spontaneously doubles, so maybe some kakis are prone to spontaneous doubling? It would make sense, since the first hexaploid ancestor was probably the product of a spontaneous doubling of one parent's contribution in a tetraploid x tetraploid offspring.