Tangelo has changed back to Mandarin

BrianWatts99 starts with ...
We live at Quorrobolong in the lower Hunter Valley of NSW. Thirty years ago we planted a Tangelo, but can't remember exactly which variety.

For 27 of those 30 years the tangelo behaved as expected, deep red orange thin skin, heavy fruiter, a lot of seeds in the centre, and very juicy with a distinctive flavour nothing like a mandarin.

It then did very poorly through the drought, but has recovered magnificently, but the fruit is different. It is now thicker skinned, peels by hand just like a mandarin, is very pithy, can be broken up into segments like a mandarin, has hardly any seeds, is still very juicy but has a much sweeter taste more like a mandarin.

So has the drought changed the characteristics of the hybrid so that it has now pretty much reverted back to an original component of the hybrid?

BrianWatts99 says...
Hello jakfruit, thanks for your reply.

There is a bit of growth from lowdown, but there is no fruit that appears to be coming from any branches down there. The tree trunk is shown in the first photo. Over the years, any branches from down near the ground have been pruned off.

The foliage (of similar age) is the same throughout the entire tree. Don't know whether it is the recent climate, but lately the tree has been fruiting in stages, meaning that there has been greenish fruit, semi-mature and ripe fruit on the tree at the same time. If ripe fruit is left hanging for a bit longer, the skin gets thicker and separates like a mandarin. At the moment, the ripest fruit isn't like that, but ripe enough to eat like in the second photo.

When sliced through the equator, the almost ripe fruit looks like in the third photo, 6mm thick skin and hardly any seeds. But very juicy, sweet and only slightly tasting like the previous fruit from this tree.

Since it was planted in 1990, fruit from this tree had a much redder skin, which was less than half as thick as now. The taste was too tart for enjoyable eating so we mostly juiced the fruit and added sugar enough to make an acceptable drink. And when previously cut in half on the equator, had a dense core of many seeds in a star pattern. Now there are almost no seeds, just as juicy and a very sweet enjoyable taste.

We are not upset about the change in fruit as now it is a lot more acceptable. The sulphur crested cockatoos think so too.

Pictures - Click to enlarge
Picture: 1	Picture: 2	Picture: 3

BrianWatts99 says...
Hi, yes I think it is most likely a Seminole. That name rings a bell from 30 years ago, but it also could be that a Piper Seminole is a type of aeroplane that I was looking at buying back around that time.

It is less likely to be an Orlando, and definitely not a Minneola.

I don't know whether it has made any difference, but for the last year or so since the drought broke, the tree has really been confused and is fruiting several months early.

Anyhow it will be interesting to see what happens to this tree over the next few years. Thanks for your input.

BrianWatts99 says...
Yes, it is actually multi-cropping. It always used to bud-burst early spring, but now it can crop new buds after good rain in warm weather. So it is possible to have green fruit, half ripe fruit and fruit almost ready to eat at the same time.

Overall, I rate the fruit now a 9/10. Hardly any seeds and sweet enough for good eating. Before it was more a 6/10 due to the many seeds and tart taste.

I don't know anything about about grafting, but maybe I could read up on the subject and then do some experimenting.

Thanks for your input.

jakfruit etiquette says...
Assuming its a Tangelo,
Citrange or Trifoliata would probably be suitable. Trifoliata is good for heavier clay soils, Citrange for lighter soils.
Dwarf rootstock Flying Dragon is a Trifoliata,
so that would be ok. Trifoliata itself is semi dwarfing.
You could also ask around locally to see what rootstock is in use.
Any rootstock shoots on the original tree would be a big help to ID, its obviously good to graft on that.
On the photo of your tree trunk, I think you can see the graft union where the bark type changes below the thin line, so its low down near the ground.
If the original tree was a Tangelo, its probably Citrange.
I'm wondering what the seeds look like, they shouldn't be too different from other Tangelos.

jakfruit etiquette says...
BrianWatts99 says...
We are positive that it is a Tangelo, not a Minneola, but likely to be Seminole.

Yes, I meant that if it has mutated from the original Tangelo to mandarin, its now a mandarin not Tangelo. There might be grafting differences, but Trifoliata is probably ok.

Interesting that I read somewhere recently that Hickson, which is a limb sport of Ellendale, is closer to mandarin ancestry than Ellendale, a Tangor.
I don't quite get how this would happen, but it may explain something about your tree.

https://citrusvariety.ucr.edu/citrus/ellendale.html
http://mvcitrus.org.au/mvcb/wp-content/uploads/2012/09/Hickson.pdf