The Tropical Fruit Forum

January in Japan is mid winter. Maybe not much local fruit in some areas. There are probably various fruits coming from the warmer areas of Japan
also stuff grown in tunnel houses or out of cold storage. I was able to find various Citrus out of season, and the Fuji apples are nowhere bigger or better.
I hear there are some pretty impressive strawberry varieties these days.

Clove tree.
Star Apple, with the gold leaf undersides.
Quince for its beautiful trunk and branches, matched by some tropical Ficus and Alectyron.
Even more so Strangler Fig with its complex mesh of entwining roots. Like H.R. Tiger artwork  from the Alien films.
Syzygiums for foliage and new growth flush tips.

That is interesting. I once tried a very large purple pear shaped Syzygium malaccense that was like a fantastic juicy pear.
The Keisui pears in your post are Nashi pears.
How do they compare with other Nashi pears ?
We sometimes get Nashi imported from China, Ya Pears. They are very light and crisp textured. Juicy but crunchy.
Interested how these Keisui compare to other Nashi.
Are you going to grow out the Keisui seed ?

There are probably two possibilities.
Grafting a seedling scion onto a mature tree might induce flowering in the scion by plant hormone activity,
ie the activity of a flowering hormone coming from the mature tree, or the reduction of an inhibitor in the grafted scion.

You could also induce flowering and maturity by physical growth.
If a seedling grows 1 metre per year, grafting a scion from it, onto a mature rootstock tree might cause it to grow and much faster, say 2 or 3 metres per year.
The placement of the scion and cutting back the mature tree to force scion growth ( top working) can result in rapid growth.

I have an interesting lemon that is very small, but the fruit will ripen (turn yellow) and hang on the tree ripe for 1 year before it starts to dry up inside.

That sounds very interesting. Any more info on that ? Any Pics ?
There are a few dwarf patio Citrus in Australia, a small fruited Key Lime and cutting grown Myer Lemon and a Lemon.
Yours might be nice fruit size for dwarf trees in balcony patio pots.

( Any macrophylla rootstocks on the way for grafting it to ?   ps That is an In Joke from Citrus General Discussion on the Forum ).

The foliage of Lemons and Citrons are fairly distinct. Citrons have long oval shaped leaves. Lemons have more pointed tipped leaves.
Hybrids plants could be in-between, but often are hard to tell from Citrons.

There are mixed answers to this.
In some species  grafting seedling material to an established tree induces maturity and flowering.
In other species it doesn't work or has unreliable results.
Your best option is probably to graft the seedling material fairly low down and use the vigour of the established rootstock to push growth into the graft ahead by several years.

Peats are often in compressed bales. Don't forget to check instructions expand it if required. Otherwise the % ratio will be out too.

I would not use 50% manure, it has poor structure ( you can heavily compress it without resistance ) and will only break down even more.
Also it probably has excess nutrients like Nitrogen.
Some people might used well aged horse stable manure, but there are better things to use.

The measurement is by volume. Sand will be heavier than mulch or pine bark or perlite.
Measuring by weight will give a wrong ratio. A kg of sand is probably 1 litre, a kg of Perlite cold be 5 to 10 litres or more. 10 litres of coco coir peat might only be 2 or 3 kg
To make 30 litres of pot mix,  I use three 10 litre buckets to measure the components prior to mixing by hand on a flat surface. ( on a clean plastic sheet ).

I use 70% coarse sand and 30 % coir coco peat mixes for smaller trees and composted pine bark based mixes for larger tree.
It is hard to recommend mixes as I am in a very hot summer /mild winter area in Australia, so that may not suit your conditions and management.

What type of mix are the trees as you received them.

As you say that the fruit came from an orchard of  a fruit enthusiast/collector, the possibilities are fairly wide.
Apart from visiting the tree for further ID, or getting a photo of the foliage, growing the seedlings is the next best option.
Most Pummelos have recognisable seedlings, different from grapefruit or Poorman / Seville. They will usually out grow both of these too.
Also as your friend suggested with the late fallen Pummelo fruit being sweet and edible, maybe the tree hasn't been harvested properly for best results.
That might be a long shot, but trying some fruit further down the track might be interesting ?
As I remember a long time friend grew a Pummelo in the cooler mountain areas around Brisbane, and that never produced acceptable fruit for them.

Just thought I would bump this topic, still interesting to find out.

Damping off is caused by pathogens, usually fungi.
It is often promoted by conditions that allow the fungi to thrive.
Some methods to reduce it are known such as
Using sterile pot media, avoid soil in the mix.
Water so the surface of the pot dries between watering.
Tall narrow pots are better at surface draining than seedling punnet flats.
Avoid dense fine pot mix. increasing the Air Filled Porosity of pot mix ( the pore space ) allows more air around seeds/seedlings and slows fungi
For tiny seed, watering once and sealing in a plastic bag may help ( the plastic bag method ). The mix should stay just damp to touch.
Coir peat is useful as it has high AFP as well as water holding capacity in a good balance.
Coarse sand about brown sugar grade particles can also be useful.
For most seed germination I use a 67% coarse sand or grit / 33 % coir peat, with the addition of 5% zeolite and maybe some perlite or similar for more air.
Some bog peat addition is known to be helpful to these type of seed raising mixes.
Bog Peat and Sphagnum have some inhibitory factors on Fungi. Bog Peat is slightly acid and fairly sterile, but fine grades may be too dense on their own and pH too low.
It is often difficult to balance the high temperature requirements to germinate tropical seed, with drying and draining of the mix, leading to very frequent watering and hence constant surface wetness. Tall pots may help as the seed will be in the damp free drained surface, with a wetter area well below the seed helping slow the pot drying out.
Another factor is don't overdo the pre mix fertiliser, or fertiliser additions on small plants. It promotes weak sappy growth prone to fungi.

It looks like a very interesting seedling, I sometimes get these type of odd seedlings in Rangpur Lime seed grows.  Dont think it is a hybrid, more of a genetic reshuffle or polyploidy change.

Ever thought of grafting the family calamansi to rootstock, it might do better and fruit faster.