Asian pear fireblight Question

Hi everybody, I planted two Asian pear trees over 10 years ago and these trees had more than enough fruits for me to share with our neighbors despite suffered from fireblight disease.
What I did to save my these trees from fireflight disease was to removing infected branches by using bleach to sanitizing after each cut.
I was so excited when these trees recovered and start bearing many fruits again but now all leaves are curled and start looking miserable.
When I sent sample of infected leaves to PennState(department of plantPathology, report states "The pear leaves showed the presence of an anthracnose leaf spot caused by the fungus Colletortichum sp. Rake and destroy leaves in the autumn to remove overwintering inoculum."
I raked all leaves and let trash collector to get rid of last autumn but this year these trees got worse and had miserable fruits.
I am thinking about spraying dormant oil this winter but because these trees are so tall, I cannot reach top branches.
Where can I find special sprayer to spray tall fruits trees without using ladder?