Said tree was about 8ft high, about 2" Diameter trunk. I planted it last year, and did not let it set fruit.
This year, I saw a tall thistle growing out of its anti-rabbit tube, so in the belief that Roundup did not attack through mature bark, and died on contact with the soil, I gave the thistle a squirt with a hand sprayer.
The thistle died - but so apparently has the tree. Firstly, all the fruit turned brown & fell off. Then all the leaves died, and I am presuming that the tree is dead.
I will probably cut it back, and leave it till next spring to see what happens, but I don't hold out much hope.