The Tropical Fruit Forum

I came across this account in a book I'm reading. What do you think? For context, this was in Brazil.



Syntropic Agriculture According to Ernst Götsch, 1st edition in English, page 81

I think that's mostly woo. They are likely seeing a minor fertilizer effect from composting and the real advantage they are getting is using a taller canopy to break up exposed citrus area. We already know that canopy cover confuses psyllids and reduces their infestation level and the downstream greening infection. This is likely what the eucalyptus plantings are really doing. Thing is, this is amelioration, not prevention.

Can anyone give me info on how to successfully germinate poncirus trifoliata seeds.?

I have twice now ordered seeds online and followed the directions precisely as printed without success.

1. Soaked for 24 hours in water.
2. Placed in fridge in most medium for 30 days to cold stratify
3. Planted at 1/2 inch depth in citrus/cactus potting mix in 1 quart pot
4. Kept soil moist and above 70 degrees F.

Twice now, nothing has happened. What am I doing wrong?

Any advice would be helpful as I really would like to germinate some trifoliate orange seeds.

I just tossed them in a finger-poked hole in potting soil in a ... 4" (maybe pint?) and left them in my semi-heated basement. (Around 60F)
More grew than did not grow.

post-script: most of mine were taken from refrigerated fruit, though.

Today's taste test of several selections, all of which survived -8°F during the past Winter.

Conestoga 006 is among the hardiest of the selections. It's also the earliest to ripen, as it's beginning to drop fruits.
The flavor is the least acceptable of the 5 fruits picked and tasted today. The bitterness isn't overwhelming, but there's an earthy component in the taste. Highly acidic, as are all of the fruits tested today. This selection is very productive

Conestoga 010
Another very productive selection, as hardy as any of the 5 types tasted today. This is the close second in the agreeable flavors. The seediness is practically equal among all 5 sampled. This one is second in ripening, the fruit tested wasn't quite fully ripe. The tree may be slightly more vigorous than 006.

Conestoga 026
Despite not being fully ripe, this was the best flavored of the 5 fruits,with a very light sweetness being discernable at this stage. It's flavor reminded me of a tart Grapefruit.

Do you think the earthiness might be an aspect of fully-ripening? Sort of like how limes are picked green because they develop off-flavors when fully ripe?

In short -- have you tested a not-fully-ripe Conestoga 6, or a fully-ripe 10 or 26?

original thread:
https://tropicalfruitforum.com/index.php?topic=24267.0

How tall is it? My 18 year old Flying Dragon is about 10 feet tall. They grow faster as they get older too.

To a point. Flying Dragon is pretty runty even when full-grown, and even species poncirus is shortish.

Longwood Gardens has some poncirus specimens that they date to the early 1980s, so they are about 40-45 years old now. They are probably 12-15 ft tall.

Truck diameter might tell you more, but my tree in SE Pennsylvania has siblings in SW Michigan, and its trunk diameter is 2x those. Indy is both colder and warmer than SW Michigan (Lake Michigan moderates extremes in both directions), so it will probably grow a little faster in the higher summer temps of Indianapolis than it would in Michigan, but a bit less quickly than around Philly, because Philly has both warmer summers and winters.

Quote from: bussone on July 15, 2025, 12:51:42 PM

Visited those trees this week. They are alive, although still really bitty in size. They survived a prolonged hard freeze without cover this winter, and they are planted in a shady area -- the combination of the two means they are all still runts, especially compared to their sibling seedling in the Philadelphia area. But they are also all alive -- even the one that got nibbled by a rabbit.

That's a heartening result. How old are those plants now?

This is their third year, I think.

I've noticed my poncirus here tends to put on growth flushes when its hot. I do wonder if poncirus needs a fair amount of summer heat, even though it's cold tolerant.

My hardy figs act like that, too.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/tpj.14993
https://www.sciencedirect.com/science/article/pii/S0888754323000617#bb0025

Polyandra and trifoliata appear to be closely-related species with a recent population divergence.  (About two million years, which is recent for citrus) Genetic testing does not indicate if one is a mutation of the other, or whether they have an extinct common ancestor.

Honestly, for F1 hybrids I'm surprised at how different they all look with no plant exactly like another despite having two dozen of them.

Not that surprising. Many of the famous citranges were just different seedlings from the same two parent trees.

I've heard of it surviving 5b, but that was down by Chelsea, which is 6a now. Your hope with hybrids probably lies along the Lake Michigan coast line and only a few miles inland from there, which is 6b. I know poncirus does okay there, because the one I gave my mother is still alive.

Visited those trees this week. They are alive, although still really bitty in size. They survived a prolonged hard freeze without cover this winter, and they are planted in a shady area -- the combination of the two means they are all still runts, especially compared to their sibling seedling in the Philadelphia area. But they are also all alive -- even the one that got nibbled by a rabbit.

You protected it passively and it died? :O

I even had a 40w heat light in there and it died. I had the lamp high, and while the upper foliage did fine, the lower part of the grafted Thomasville must have froze. Rootstock survived, though. The rootstock was US-942.

So, to summarize:
Thomasville froze.
US-942 survived.
Madison's unlabeled citremon survived.
Prague survived.

Morton died, but I don't think it had anything to do w/ winter. It was dying in the autumn.

It was a weird oitcome to say the least.  One of my fig trees was severely damaged but my two seed grown grapefruits were unfazed other than leaf damage at 10 degrees.  My owari satsuma which has been in the ground for nearly 10 years sustained way more damage than those 2 grapefruit trees.

How big was the fig?

My neighbour wants coldhardy figs (south Germany). Anyone here sells cuttings/trees?

what zone are you in?

Quote from: Sunmicroman on June 25, 2024, 04:42:31 PM

I am trying US 812 in my yard. I planted it this year after buying it from Madison. I am hoping it is hardier than US 942 (another Sunki-trifoliate hybrid), as that had disappointing hardiness this past winter.

What is your experience with US-942 and it’s cold hardiness?

It survived 7F for me.

I had assumed the rootstock for my Thomasville (which didn’t make it) was poncirus, but after checking the tag it was US-942. The rootstock is alive and well.