In the three photos you'll see my Fukushu Kumquat. The far left photo was taken late this summer. The center and right were taken today.
As you can tell, more than half the tree has passed away. Over the past 2 months the branches began losing leaves and actually turning black. The fruits on those branches--which were about the size of blueberries--had ripened (turned orange).
Oddly, the remaining branch has 4 healthy--still green and roughly walnut sized--kumquats on it. Given that it was overdue for repotting, I went ahead and moved it into a larger (12") pot with new soil and fertilized it.
What's left of the tree looks really healthy. Here are my questions:
1) What the heck happened?
2) What kind of future can I expect?
3) Will any new branches bud?
4) Will that trunk support a mature tree, or is too butchered?