On the fireblight resistant list from Corvallis - I had two Chinese pears that blighted severely for me several times - Ya Li and Tsu Li. Tsu Li never lived long enough to fruit though Ya Li fruited for a few years on my second attempt at growing it.
El Dorado is listed and it has been good for me so far (it was not planted until the year after our very bad fireblight epidemic of 2015) but the information from Australia states that it is very fireblight sensitive - ???
The literature about El Dorado indicates that it is fireblight resistant. This is from an Oregon publication dated March 1963:
“In storage tests. El Dorado has not developed scald or core breakdown. The fruits have stored well at 30° F. until April and May. Unlike Packham’s Triumph, it has not been susceptible to scab and blight or storage scald.”
However, if you read Clark’s download of the Australian pear information, it states that El Dorado is quite sensitive.
There are different strains of fireblight as your likely aware. Fortunately the one we have in this area is not the worst type. I grow several Eldorado here with no problems yet. It has not bloomed until this year. Menie has had dozens of strikes. Some pears are not at all vulnerable until they bloom. Some constantly have problems. Menie is a rapid growing pear and anytime cells divide quickly they provoke fireblight. The other trees in great danger bloom a long time. Blooms are rapid cell division. That’s why fireblight attacks no tree in the winter in cold climates. Many of you know of the 65/65 rule which refers to ideal temperature and humidity for fireblight. So you might wonder how do I know there are worse types? I have received scion wood from various places and it looks perfect however after I graft it the tree grows rapidly and dies to the rootstock. It’s clear it was that scion that harbored the illness. At first i thought the rapid growth was the cause but all scions had rapid growth. Then i believed it was chance which was partially true but why only scions from 1 area? I might make 5 grafts and 3 die 2 dont and never had any other problems. It was then i realized the wood came infected even with a bleach bath.Had i bathed it with copper i might have been wiser since copper inhibits the growth of bacteria. Why did the new strain of bacteria not escape and thrive here? I don’t have the answer to that. Some trees are fireblight magnets Eldorado is not that tree in my location. I might suggest in other locations that are very warm with high humidity e.g… southern United States, Australia even a kieffer is a fireblight susceptible tree. @rayrose and i had this conversation years ago it’s not the same strain of fireblight it’s a more aggressive form in the south and ideal humid conditions exist nearly all the time. That’s why @coolmantoole started a thread specifically on Southern pears. Like with any observation It’s not fact It’s a hypothesis I think is true about fireblight. Fireblight is still a very mysterious illness picking some years to be worse than others for reasons I can’t understand at times. My belief is that insect and bird numbers / migration are a factor in severe fireblight years. Cicada damage brought on the worst fireblight I ever saw 17 year cicada's woke up hungry. 2015 was a bad year here for fireblight Late season Fireblight
So true! Having lived in the south and seeing fireblight there, I can attest to its virulence. Bountiful Ridge Nursery may have predated your journey into pear growing, but they had a cultivar that was named “Blight Resistant Bartlett” touted to never have FB. It survived only three of four years in my north MS orchard. I was fairly new to pears at the time and I remember when TO Warren and a few others visited my place he noticed a FB canker on the trunk of the tree that I had not recognized. The tree died the following season. It never had a chance to bloom!
Fireblight here is a different thing. As you probably know, Bartlett pears are commercially grown in the two counties just north of my area - Lake and Mendocino. Both much hotter than here. Also very dry in the summer with little morning fog and lingering stratus to keep things cool. They usually do not have very much problem with blight. I don’t think they routinely spray with antibiotics. We are cooler and also rarely have significant problems. But, about every 10 years or so the 65/65 rule must happen.
A late rain along with an unusually warm spell during bloom seems to start thing rolling. 2014 was bad but 2015 was horrible. Every ornamental pear in Santa Rosa was affected - none died that I know of. I lost mature trees of Urbaneste, Passe Crasane, Buterra Precose Morettini, Orcas, Tsu Li, and Ya Li plus multiple grafts including a Harrow Delight and every Bartlett or Bartlett clone. A young tree of Abbe Fetel died.
White Doyenne and Winter Nellis were so damaged that I removed the entire trees. I, of course, had to cut out blight in other trees as well. But despite the carnage, many supposed blight sensitive cultivars had minimal to no strikes including Comice and Hosui. BTW, the Seckel was badly damaged in 2014 and again in 2015 but survived as a shadow of its former self.
Since 2015 I have had only a few strikes. The last was on Tennosui due to rat tail bloom that I didn’t notice until I saw the strike. We are almost completely post bloom now with the next warm temperature due next weekend. But the humidity will not be very high.
I have suspected that insects spread fungal diseases in pomegranates and in pears, last year wherever they bit the leaves, many of the bite holes turned black, and then the leaves turned black right after. This happened in both pomegranate and pear at the same exact time making me wonder if it was the same exact disease infecting both of them. Strange how confusing nature can be.
Greetings: What is "rat tail bloom? This is the first I’ve heard that term. Is it what Southern Bartlett does every year where it sends up long shoots from a bloom cluster and blooms again from that shoot? That’s a fire blight resistant enough variety to grow here in SE Georgia and most other places in the Deep South, but that habit makes it a good pollinizer for mid season bloomers along with the early season bloomers that bloom with its primary bloom.
Last year was a bad year for fire blight for me, not that I lost any trees. However, Goldenboy repeatedly got strikes in the spring and early summer. It was an even worse year for leaf spot. My Baldwine Pear suffered greatly with that. Here are the conditions reeked havoc with my pears generally last year. We had an insanely warm and wet winter. The warmth actually saved the plums from what came next because they did not get their chilling hours in until the cool spring, so they all bloomed late enough to miss most of the damage. The early blooming pears started blooming in late January. While blooming they got a damaging frost that would not have destroyed the crop were it not for the 3 weeks or so of weather in the high 30s at night and 50s in the daytime. This was when all the plum trees got their chilling hours. This delayed the mid season bloomers to well in March so they bloomed fine, but it was still cool and wet. Then we were hit with a hot and dry but very humid April and May. Then we were hit with an insanely wet June, July and August where it was very hot but rained every other day. I had to check Goldenboy, LeConte, and Tennessee every day through that and cut fireblight off. I also sprayed constantly with liquid copper. In that June and July rain is when the leaf spot hit with a vengeance. All the mid and late season bloomers that were mature enough made good enough crops. But it was a constant fight with disease that season. And the early bloomers which are my biggest trees and heaviest yielders were a total loss. Southern Bartlett was the only one that made a few pears but only on account of that habit of having a second smaller bloom. Last year was a pretty good year for plums, but I had a fight with splitting and brownrot on some of late ripening ones because of the near constant rain in June. In Georgia its generally best for plums to ripen in May and early June before the summer monsoons hit. Monsoons don’t seem to affect pear ripening as much, but they do invite leaf spot when they are constant. Nearly hundred year old pear trees that I know about suffered mightily with it last year. So far this year has been disease free.
Ah, that explains it. All low chilling varieties do that. Tennessee and Goldenboy are the worst when it comes to that. Also all the pears bloom every time a tropical storm passes through the area without fail. If we get multiple tropical storms or near misses in a summer and fall, the pears will send out a flush of flowers after each and every one. They also always bloom in October and November between cool snaps. We often don’t get cool enough weather to send them into full dormancy until after Thanksgiving and sometimes not until Christmas. But the low chillers will bloom after every period of cool weather followed by warmer weather until they are forced into full dormancy. So far I have not had any FB damage on Tennossui, but this is it’s first year blooming. (By the way, what do you think of it’s fruit quality if I may ask? Is it more European pear like or Asian pear like? I hear conflicting reports.) It’s seed parent, Tennessee, is the worst for nearly blooming out in the fall, so it won’t surprise me at all if Tennossui inherits that tendency. I attempted a Shinko a few years back, and it completely bloomed out every fall and would not bloom in spring at all due to South Georgia’s tendency to have long hot Indian summers following a cool snap in October. I’m attempting Shinko again because I need a reliable pollinizer for Korean Giant. Hopefully it does not bloom out in fall every season like the one I pulled out did. Thanks
Here is a photo of rat tail bloom as it occurred last year on one of my pears. I cut it out as soon as I saw it and no fireblight happened. As you know, fireblight really likes to enter the tree through blossoms but it can infect the tree in other ways - injury to bark and leaves by hail, insects, sapsucker drills, and probably many others. But blossoms are the easiest. A couple of years ago I had a strike on my Tennosui tree from rat tail bloom that I didn’t notice. I lost a big limb but the tree survived. For me, in my area, Tennosui is a spitter! I have topworked the tree to other varieties. My good friend Ethan Natelson sent me the scions as it is a very excellent pear in Houston, TX. I think we don;t have enough heat here.