I have three asian pear trees. But my 20th Century only was recently badly hit by fireblight.
Is it generally more susceptible??? It didn’t get much at all last year. But we are having a very wet spring, and it never seems to stop.
Any suggestions or advice? I cut off two branches today and the tree is only two years old.
John in 6b kentucky
I’m in zone 9b and my grafts also took off the first year, but then just died off the next one. The other varieties (shinseiki and hosui) are thriving .
Nijisseiki is susceptible to fire blight.
Are you sure its not Fabraea. My 20th Century lost 3-4 spurs to Fabraea. At least at this point it seems like it since the branch has not been infected.
Your best bet is aggressive pruning of any infected wood (8–12 inches below visible damage), sterilizing tools between cuts, and removing water sprouts as they pop up. Once the tree is larger, good airflow and consistent thinning will help, but in young trees it’s always a tough figh
Thank you everyone for you feedback, it killed whole branches for a distance of about 16 inches. I cut all of that off. May have to cut off more.
Right, I will make sure there is better air circulation. We have had tons of rain, but the branches were probably also too close to each other which only added to the problem.
Mini orchard dude, what is a water sprout???
I have Hosui Asian pear, Shin li, and Nijiseiki.
Is there a better Asian pear with good flavor and resistance to Fire blight that I should consider that would also be a good pollinator for the others?
The term :“water sprout” refers to a very vigorous and usually vertical growth.
Last year my two year old 20th Century got severe fire blight. I thought it was a goner, I pruned it severely, taking it nearly back to the rootstock and was planning on either grafting over if it survived or taking it out completely but never got around to it. This year it’s growing vigorously with no signs of fire blight……so far.
My 20th century got hit hard this year with blight. Only about 10% as much on the Anjou pear right next to it. Also got my pink lady apple trees bad this year too. Had bad blight when I moved in, but last 5yrs or so have been pretty good, not sure what changed this year.
What are your other two trees?
The magic weather for fireblight is temps above 60 (above 65 even worse) followed by any kind of dew/rain while trees in any sort of bloom. This year was very bad in our general area because of on and off warm spring temps followed by rain.
Once the FB is present in the orchard, young shoots/new growth get infected throughout the summer if they get any sort of damage (even wind that whips them around can do this - but things like hail or heavy wind is worse)
You’ve already gotten good advice on cutting out strikes & leaving an ugly stub. You then wait till winter and cut off the ugly stub.
If you spray your trees there is a shoot growth controller called “apogee” which hardens off new growth. There’s also something called “actiguard” which apparently helps. I have not tried either of them, but after this year I might.
Next year, if you are feeling ambitious you can spray streptomycin when trees are blooming and risk is high (it has been above 65 F and it is going to rain/dew). Also, If you spray trees during bloom, and it has been warm, you have to add strepto to the mix because spraying is a “wetting event”. Also, you have to spray strepto before rain/dew - it doesn’t work after.
Most of the recent research indicates this doesn’t matter (on a large scale). However, if you only have a few trees then I’d probably still do it. You actually have to dip tools in a sterilizing solution for something like 60 seconds (for 70% alcohol or 1-2% bleach).
I have too many trees and sterilizing between cuts was making things very hard. I did it for a couple years (rubbing alcohol because bleach was destroying my tools) but then I read some studies that by the time you’re cutting strikes, the bacteria are already further down the tree so sterilization didn’t really matter. Now I just do it at the end of cutting strikes in a day - not between cuts.
One more important thing! If you have a young tree like this, which wouldn’t produce fruit anyway (or an older tree where you’re not interested in production that year), remove the flower buds before they bloom.
“Flower removal in young blocks and removal of late blooms limits the numbers of flowers and thus reduces potential points of infection. In two 2020 trials flower removal at pink bud stage for young nonbearing trees reduced infections to zero, compared to 71 to 77 per 100 clusters in water treated [control] and 5 to 17 per 100 clusters in soluble copper treated trees (DuPont et al. 2022).”- WSU’s fireblight page
Thank you everyone for the input. It seems here in wild Kentucky I face a lot of challenges, and this spring we had them all.
Warm days and then frosty nights on and off with rain, heavy winds, and trees blooming in the middle of all of that. For the first time ever I got quite a few deformed baby pears and apples I assume from partial pollination and freeze.
New baby leaves were also damaged and then lots more rain. I also had three vertical branches all growing too close to one another and not allowing those leaves to dry out. Lesson learned there and a lot of good information and input from all of you.
Thanks!
John in Kentucky
Well it turns out my 20th Century was indeed fireblight. None of my other fruiting 8 pear trees or 4 apple trees have any issues. A budy also had a problem with fireblight in California with his 20th Centuey. This particular variety must be susceptible.
Never had any fireblight ssues until this tree flowered. It is transferred by the pollinators.
way back in 2015 @mamuang warned us about 20th C pear… =(
It’s on quite a few “resistant” lists but it seems like maybe it shouldn’t be…
I have 20th Century grafted onto a Hosui pear tree. My experience has been that Hosui is very susceptible to a form of blossom blight, which may be Blossom Blast or Fireblight; but the 20th Century seems to be immune to it. Of course susceptibility might be different here in the PNW than in Kentucky.
Anyway, spraying with copper at the right time cures the problem.
I have many Asian pears grafted to a few trees. Of the 15 or so varieties in my yard, the most fire blight susceptible were Shinseiki and Raja. Both were dead by fire blight after 3 years of actively growing. The rest of them got fire blight here and there but it has not kill the whole branch or the whole tree.
Almost all Asian pears are susceptible to fire blight to some degrees, esp. when the weather is wet and warm right when flowers are blooming.
Blossom blast does not kill a branch or a tree. It only wipes out blossoms for that year. Fire blight can kill for sure.
I like my Korean Giant. After 17 years, it has continued to do well and has minimal fire blight damage has and produced delicious, large pears for all these years.
Raja and Korean Giant. I’ve only been hit once since '09 from what I can tell.
Thanks everyone for the input!! Really appreciate it. Going to add a Korean Giant to the line up.
John in Kentucky
Korean Giant has been my best overall prooducing tree so far. Compared to all my peaches, nectarines, plums, apples, paw paws and 3 interspecifics.