I’m constantly looking for fireblight research information for pears and coming up without adequate information so I wanted to share what I’ve found. Please add to it if you can especially if you have grown varieties not mentioned that are resistant or if you know some mentioned are not. The three main types of pears we can grow are european / french (not fire blight resistant), Oriental hybrids like Kieffer, douglas, orient etc. which are crossed with sand pear and are resistant to fireblight , Asian Pears (like Korean Giant,chojuro etc. mixed rating on fireblight suseptability). I’m not sure all of the pears which are Fireblight resistant because there are around 5,000 types of pears.
Many pear rootstocks are very resistant to fireblight. To name a few of those resistant rootstocks OHxF333,OHxF40,OHxF87,OHxF97 are the most common. Those Old Home x Farmingdale rootstocks were specifically bred for the purpose of fireblight resistance. There are other rootsocks used for a variety of reasons such as Hawthorn,Betulifolia, Winter Nelis, Pyrus calleryana aka callery, Pyrus ussuriensis aka harbin pear. New varieties of rootstocks such as Pyrodwarf,Pyro 2-33 are quickly becoming available and have some promising features. So where to buy rootstocks? sierragoldtrees.com,copenhavenfarms.com, cumminsnursery.com, burntridgenursery.com, willamettenurseries.com, lawyernursery.com to name a few. Stay away from any pyrus communis or quince in my understanding as they are not fireblight resistant. I would like to discuss rootstocks more but lets just say generally people buy them for price, scion compatibility, soil, drought, dampness, and disease tolerance, and age the rootstock influences fruit bearing. So pyro rootstocks might be bought because they bear in a couple of years but cost $4 each if
bought 100 at a time. Betulifolia aka bet rootstock is highly compatible with asian pears cost $1 each but sucker like crazy.
Some nurseries appear to specialize in fireblight resistant pear trees for wildlife use such as http://www.wildlifegroup.com/shop-for-pear-trees. Fireblight is a bacteria called Erwinia amylovora. I treat Fireblight using several methods but none of which are great 1.) Spray with copper 2.) Spray with 50/50 white vinegar and water solution 3.) Spray with Antibiotics 4.) If all else fails amputate the branch or remove the tree 5.) Plant resistant pear trees. Some varieties of pears are more resistant than others as mentioned above which are mostly european crossed with sand pears. Some have no flavor or a gritty texture and others are very good. Kieffer and pineapple still get fireblight but I’ve never heard of them dying from it so they really are resistant. Pears such as the ledbetter on the wildlifegroup.com website are reported to not get fireblight at all. The wild callery in this area do not have a spot of fireblight. The problem is pears such as my bartlett are not really resistant it just blooms early and dodges fireblight because of its bloom time. That’s true of seckel as well so if fireblight hits it it will hit it hard. Below is a list of the reported fireblight resistant trees some of which are and others which are not in my area.