Disease on Asian pear trees
I have two Asian pear trees grown on my backyard -- Hosui and 20th century. There are about 7 yrs old, and have been producing fruits every year. I live in Dallas, TX. My main problem is that I have been fighting fireblight disease every single year, mainly shoot strike in early spring (May - June). My estimate is that I loose about 50-80% crop due to fireblight every year. I did some research on the Internet, and somebody suggested to spray liquid copper during dormant. I did that last year and it did not appear to make any improvement.
My question is: Does any body in this forum know any "proven" or perhaps a "silver bullet" method to address this issue? I am really running out of idea on what to do next.
Recently , in mid July, I have some sort of leaf fungus (see photo). I am suspecting it might be some residue left over from the last fireblight strike ??