Problems with Quince

I have a large quince tree but rarely get to eat any of the fruit as it suffers very badly with brown rot.  I religously pick off infected fruit as soon as I see it.  I pick up and burn all the leaves and keep the area under the tree clear but the problem is geeting worse. Is it because the tree branches are covered in lichen and this is harbouring the spores?  It is far too big to scrub free of lichen.  Any thoughts please?

Hello Pansy2

I pick quince each year from a wild hedge nearby. The fruit also gets soft brown areas, but seems to me that they appear when the fruit has been left to over ripen. I pick the quince to make jelly, and try to do that when there is still some green showing. The brown patches appear mainly on the fruit that is out of my reach and therefore left on the hedge.