Four square metres, kept badly and recorded carefully.
Second year of nothing. It flowers, generously, and then drops everything within a fortnight. The tree itself looks healthy: good leaf colour, new wood, no sign of anything eating it.
The likeliest answer is the dullest one. It is the only pear within sight, most varieties will not set fruit from their own pollen, and I have no idea which variety this is because it came with the flat.
So the plan for next spring is to stop improving the soil around it, which was never the problem, and find out what it actually is. If it needs a partner there is room for a dwarf against the south wall.
Two seasons to work out that the tree is lonely rather than ill. I do not mind being slow about it, but I would like to stop treating symptoms.