Apple tree not producing

Hi folks looking for some advice.

I have a small family apple tree (Grieves and Coxes I think) which is planted in the corner of my plot.  It is 6 years old and only about 4 ft high (seems to be on very dwarf root stock).  I have never actually gotten any apples off.   Is there anything I could do to help it produce fruit (any that do form end up the size of a ping pong ball, rock hard and covered in brown scabs).

I was also wondering if it would be ok to plant some of my strawberry runners underneath it to keep the weeds down or would they take water and nutrients away from the tree.

Sounds like you need to give your tree a good spray in late winter with a lime & sulphur solution, if the UK even sells this. It's an organic method and will suffocate a lot of nasty stuff that could be bothering your tree, like the cause of the brown rot.

My trees were also slow to produce until I started giving them a yearly fall mulch of lots of old manure and let the winter rains water it down. Tree health and production have improved tremendously since then. Also, find someone who understands tree pruning to show you as you'll need to do a bit each year to improve cropping. Apples love to put out lots of growth at the expense of fruit, so pruning is a must if you expect fruit.

Also, you need to keep the area below the tree clear of fallen fruit and infected leaves so the diseases don't perpetuate themselves. The strawberries won't compete that much with the tree roots but it will be impossible to give the trees a good feed if the plants are in the way.