This time of year I use vinegar and water only if I have a bad FIreblight infection. The vinegar and water will make you trees look pretty bad so don’t use if you have any other choice. Vinegar is an antibacterial but it’s also a mild herbicide. If the tree is crawling with Fireblight I use it. Pre bloom I spray fertilome antibiotic mixed with water. When the trees are dormant I spray liquid copper. Amputate infected branches several inches below the Fireblight strike. .