What kind of citrus is this

Question

I have this tree in my backyard. I can’t figure out if it’s an orange or some kind of sweet lime (I’ve see a kind in India that’s a lime but quite sweet). It’s too sour for an orange and too sweet for a lime. The fruits take a long time to get to yellow. I don’t know if that’s how it’s meant to be, sweet/sour, or it’s just an orange tree that’s somehow not producing sweet fruit and needs to be fixed. I see some leaves curling and dead branches, so there could be aphids or scale bugs that I might need to take care of. What does this tree need?

Any help would be appreciated.

TIA
Norm.

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Answer 1

It is normal for citrus fruits to take a long time to mature. For oranges, anywhere from 8 to 15 months is possible depending on the variety. One possibility is that your fruits aren't mature yet, and that they will continue sweetening, so it's best to leave most of the fruits on the tree and taste one every few weeks to see if they're ripe yet. This article has more information:
https://www.gardeningknowhow.com/edible/fruits/oranges/harvesting-oranges.htm

There are also several naturally sour orange varieties, used for grafting rootstocks, ornamental trees, or to produce fruit for making marmalade. Here is more information:
https://www.hort.purdue.edu/newcrop/morton/sour_orange.html