Nashi Pears Disease

Hello all!
about 3 years ago, after some violent forest fires that burned down all my small farm i decided to have a small area with nashi pears.
Until last year all OK and with great growth (i have permanent irrigation) but this year i’ve noticed something different with them.
It looks like somekind of rust… on the bark, pears and leaves… but the pears taste great!!!
almost 2/3 of leaves have fallen after flowers
Does anyone knows what can be happening…
I’ve google’d it but nothing similar!!
Thanks