No fireblight here. We had good rain this year, but was the coolest summer we've had in a long, long time. Our summers are usually very hot with almost unbearable humidit, not this year.... so far.

Same here (from the same state is probably why). Many times it was prime wetness but we lacked the heat that really brings out the FB. Brown rot has been worse however, it likes it warm, but above 90 and it starts to get unhappy. So, fewer 90's this summer means more brown rot.

Scott

Yes Clark. I'm in the extreme eastern part of the state and had a surprising problem with fireblight.

Namely in the late summer, in which fireblight wouldn't normally wouldn't occur here, fireblight has occurred. Fireblight is most commonly spread during bloom (hence the maryblyt and cougarblight models).

Normally our hot KS temps of 90 to 100F will "burn out" blight strikes, but this year has been so cool and wet, fireblight has gotten a good foothold in the late season. I may lose a Red Bartlett to it, which is badly affected.

I never have had it till this spring. It's on all my apple trees! I've been cutting it off but it's still spreading and killing new growth and grafts too. I wonder if I brought it in when grafting, or it's just the weather? It's been cool and wet here with last winter being really cold here in Michigan.

I used antibiotic on a clapps favorite pear tree during bloom and it was hit the hardest because it's more susceptible than others I have. I used white vinegar with water 50/50 on another clapps favorite and it had no fire blight. I think the birds or Japanese Beatles are spreading it. There is a small orchard down the road that every tree has 70% or greater damage. It made me cringe when I drove by. Olpea are you using antibiotic to control it during bloom?

This post was edited by ClarkinKS on Wed, Aug 13, 14 at 18:32

"Olpea are you using antibiotic to control it during bloom?"

No. I have figured my blight susc. pears are on borrowed time and I'll let them die when their time comes. In the eastern part of the state, we get plenty of ideal blight weather.

I've seen one of the neighbor's pear trees collapse and die from it, and one of mine almost died from it several years ago. My two most susc. trees are a Red Bartlett and regular Bartlett. Both of them have blight badly this year. If they die, I'll replace them with less sensitive varieties, or some other fruit.

I have been hit hard here where we never have it very bad. I didn't spray for it and will from now on. We have had days of heavy rain followed by heat waves and it has gone crazy. I decided to forget about trimming it out as it wasn't doing any good. Most of my trees are four or five years old so I just whacked the worst ones off above the lowest branch above the graft. I know that seems extreme but I was going to do it anyway in order to train them to a trellis system. I bought spectracide and actinovate but never got to spraying. Most advice I got was that it wouldn't do much good at this late date. I've never had fireblight from blossoms though, it's been late in the summer these last two years.

I notice we are each talking a bit differently about whether the heat brings it on (myself and mhg) or suppresses it (olpea). I don't think we are contradicting each other but someone reading this may think so. The fact is around 80F is ideal for FB. What we had in our usually bad earlier spring was on those wet days it was more like 60s-70s and so blight was not bad. As olpea mentions, really hot weather also suppresses it. We have had some bad FB weather after the bloom period, but at least in my orchard I expect there was not enough inoculum from the earlier strikes to let it get out of control. In June I got a few small strikes and that was it. We had a few really bad early high 90's heat waves which could have also helped flush it out.

Scott

I have a pear tree dying from it and a MacIntosh apple tree that seems to have some on it. The pear tree is in a spot where I want to plant blackberries, so it's going away. The MacIntosh has a large number of small spots of it, so I'm not sure what I'll do with it. I never see any apples, plums, or pears get ripe because the squirrels take them all by the time they're as big as a golf ball. Weather here has been cool and rainy. Record low high temperatures and record low low temperatures this summer.

From reading about fire-blight on this forum I've decided to take reasonable prevention measures and at the same time move toward varieties with some degree of natural resistance.

Scott. The temperature range is interesting and could be used as an aid as to when to spray.

We only hit 90 once. We had one day at 86. The rest of the time we were at low 80's to seventies. It's supposed to be in the forties right now but I haven't checked. I would have it really bad then if the cool suppresses it. We have been in the fifties and sixties at night. It's been really good sleeping weather all summer. I could have left the pool covered!

Scott,

What you say about temperature is spot-on as far as here in Denver. We usually have a few cooler days around 80 after our mini monsoons and then the temperature picks up back to the 90's.

I'm not ready to give up on the heirloom apples as I have not seen what spraying will do to control it. Weather has never been like this as far as I can remember. When I was in my teens we had a downpour every afternoon around 4:00. Then we went to drought conditions for a couple of decades. Now we have thunderstorms regularly but never know where they will hit. In between these thunderstorms we have mini monsoons interspersed, which often seem to coincide with hurricane weather in the gulf.

Scott I'm glad you brought that up because as we understand fireblight better it's less intimidating. I had 3 small pears hit hard this spring and I trimmed off the infected branches and sprayed with vinegar and water only and it knocked it out on those. If it hits the trunk I don't think there is any stopping it.

Clark if vinegar and water had meaningful affect on FB it would be less intimidating. I don't do anything to treat FB besides cutting it out and it usually goes away and doesn't return- except when it does.

It can be a minor problem or a devastating one. I've been managing it for many years now on many sites and it is a mysterious disease. Why does it show up at one site one year on many trees and then the next it shows up at an entirely different site even though they may only be a few miles apart and the previously infected site has nada?

By assuming your anecdotal connections are the reason you have controlled FB just adds to the confusion, IMO.

Even antibiotics have to be timed perfectly to control FB and that's why even commercial growers who are watching their trees full time are sometimes wiped out by it. You think the researchers overlooked vinegar?

ClarkinKS. Your vinegar/water solution is interesting. Hope it continues to work for you. I'm assuming that your using it as an after fire blight strike to prevent more spreading. Good luck

Scott. After reading about the temperature range for the spread of fire blight, I'm not as confident that my serenade spray this spring was what kept me blight free. Thanks for explaining in a way that us none professionals can understand the idea.

I know what you mean Harvestman what works at one sight may or may not work at another and it's subject to conditions sometimes out of our control (eg. temp & moisture). We do know fireblight is a bacteria and vinegar is antibacterial the same as bleach or antibiotic sprays. I spray the tree after I trim off the blight with vinegar and water for the same reason I wipe my tools down with alcohol. Here are a couple of great articles
http://www.ext.colostate.edu/pubs/garden/02907.html
http://homeguides.sfgate.com/treat-fire-blight-white-vinegar-spray-22596.html
2010Champsbcs yes I spray after I cut out Fireblight and in cases where one tree is in the middle of two showing slight signs of blight I spray as a preventive. The things I do work for me but there may be better ways to do things.

This post was edited by ClarkinKS on Sat, Aug 16, 14 at 6:35

Milehighgirl My experience in my orchard is similar fireblight can spread any time. Experts say during bloom is prime time and so many orchards spray antibiotic sprays around that time (eg. Pre bloom) . It does stay dormant in branches of affected trees overwintering in those cankers and hitting an orchard hard the next year. I look for cankers and trim them out. I definitely cut Fireblight out immediately when I see it to stop the spread during the growing season. Time is not on our side with Fireblight. All the trimming out can cause problems of its own because it causes an open cut and new growth which Fireblight loves. This time of year after the cut Is made to remove Fireblight I cover it with tanglefoot to prevent disease from entering.

Clark, I don't think the article about using vinegar has much credibility. I would look for university guidelines based on actual research for that kind of advice. UC Davis is extremely predjudiced towards organic methods so if vinegar has been shown to actually be affective I suspect they'd have reference to it.

With FB it isn't so much about one thing working at one site but not at another it is about the unpredictability of it, making anecdotal observation of results of treatments, without any control (untreated trees), close to worthless.

Here is the best article about FB I've read.

Here is a link that might be useful: controlling fireblight

Clark, I know little about fireblight having had little experience with it, but I think Harvestman is right.
Having said that, Harvestman, let's not paint the picture that UC Davis is a bunch of hippy eco-nuts who only publish holistic herbal rubbish. I've watched many UC Davis fruit growing videos online (probably among the best, if not the best produced) where many synthetic chemical controls were discussed and even suggested. So it's not as if they've sold out to one side. I think they've made the conscious decision to deliver information on organic controls in addition to chemical. I have no problem with that at all. Personally, I don't think much of organic control as it has proven to be overall ineffective for me, some things work...most don't.
I like UC Davis and am thankful for the contributions they've made and the very helpful videos they have produced.
Kinda off topic I know, but I've heard you mention several
times about them and I know what you mean, but some folks might get the sense that harvestman thinks they are a joke. You don't think that...do you?

Their advice to home growers I've seen lately is, in fact, quite prejudiced towards organic controls, although I've not done a thorough survey. A UC Davis link was posted here recently that I actually found offensively one-sided (because relative efficacy was not mentioned), but I forget what it was in reference to.

The organic trend is no longer something I associate with hippies- not for about two decades- been to Whole Foods lately? Plenty of Republicans in the aisles, I'm sure.

I've never been in a Whole Foods...don't have them around here. I'd imagine those Republicans are in there buying those organic tree nuts. You know what they say "you are what you eat".

i should have mentioned that, no, I don't think UC Davis is in anyway a joke, it is one of the top 5 agricultural universities in the country and I often refer to them for info. But the info they supply for backyard orchardists is slanted towards the CA culture, IMO. Their advice to commercial growers doesn't do this.

I also prefer least-toxic but AFFECTIVE methods- who doesn't? But when offering suggested treatments, relative efficacy should be a primary topic as well as the relative difficulty of the increased number of applications often required of organic and other less toxic alternatives.

IâÂÂm a person with only a few trees and little to lose if I make a mistake with my organic approach to preventing fireblight, in contrast to a person with many trees or even enough for their livelihood. I donâÂÂt feel like the commercial growers have the options to tinker around like I do. They must use tried and proven methods. One thing in my area is certain; fireblight can kill or severely damage apple and pear trees. My approach will continue to be organic and then if it doesnâÂÂt work I will move to other approaches. My personal opinion is that we need research in both approaches because I believe most big time fruit growers would go all organic if the data supporting organic methods were there. As much as I enjoy attempting to grow organically if I was doing this on a large scale I would use the most proven methods. When all of you post information IâÂÂm the one who benefits the most. Thanks

Clark,

All the trimming out can cause problems of its own because it causes an open cut and new growth which Fireblight loves.

You are too right. The new growth is causing me problems, which is not something I had anticipated. Ugh. Just got to get through this summer then do some serious spraying this winter and spring. Live and learn!

I have never had trouble with June bugs or other chafers here before either, but I suspect my secret garden is no secret any more.

There is plenty of research being done on organic fire blight control, especially because of controversy about the use of antibiotics which had been acceptable to organic standards and has now either been taken off the acceptable list or may be soon (can't remember which and can't be bothered right now to search it out).

The days when organic production was a fringe movement is long over and it is a part of research at many agricultural universities including UC Davis, Cornell, and MSU. Many private companies are also in the game including in Europe and Japan.

In Cornell's production guides there is always a discussion of available organic pesticides that often includes information from research they've done about recently released organically approved products. It was a Rutger's team that developed Surround- the very product that made commercial production of apples in the east possible.

Years before, a joint project by the Rodale Institute and Cornell had determined that viable commercial organic apple production was not possible in the northeast (bet there were no articles in their magazine about that).

The vinegar worked for me this year and I will continue to use it. Everyone can decide for themselves how to control their Fireblight. Since I grow several acres of fruit I'm well aware what Fireblight is capable of. Will the vinegar method work next year? I don't know but I do know my trees were all sprayed with commercial fungicides before and all got Fireblight. My neibhors farm is being hit hard right now and he used fungicide. Bacteria do not typically survive alcohol, bleach, or vinegar. The only question becomes will 60/40 or 50/50 mix be enough vinegar to control fireblight.Vinegar is also a herbicide at stronger doses. Im not suggesting a commercial grower stop using commercial fungicides and pesticides.

Why would a fungicide have any efficacy against a bacterial infection in the first place?
I think vinegar would have to maintain its bacteria killing properties well beyond the time of application to actually work or a single spray of copper in spring would also be affective.

Harvestman copper can be sprayed on your trees but not once they leaf out so what else would be effective besides vinegar? Antibiotic pre bloom is what I used on highly susceptible trees this year.

I use a copper formulation on my tomatoes, but maybe similar products are not available in smaller quantities that the 2.5 gallon jug I paid over $100 for.

Harvestman another method I started using for my pears is grafting higher as the wild pears I use as rootstock at my location show no signs of fire blight. Then I can always cut back to the root stock and graft over with more resistant pear varieties when I need to without having to grow roots again. I got the idea years ago as I walked through my field cutting out wild pears and it hit me I never saw one with fire blight. By using that method I can grow some heirloom varieties such as clapp's favorite that are highly susceptible to fire blight but have a wonderful flavor. The downside to that method is I trim off wild shoots at the trunk every year. My point is most people use a fungicide of some kind and a pesticide to control everything and maybe dormant oil spray in the winter and copper or antibiotic in the spring but what about summer? To MileHighGirls point the fire blight I've seen this summer came in the summer provoked by the moisture and temps and not during bloom time. We get good wind storms that break branches which leaves an open door for disease. Moisture causing to much new growth is another recipe for fire blight disaster. I used to cut off the fire blight only because what else can you do? The what else is vinegar because in the summer you have two problems your pears and apples are almost ripe and you cant spray anything that will harm your crop but at times you need to spray something that kills the fire blight. Vinegar is not my solution it's one of several methods I use against a formidable adversary.

ClarkinKS. One thing is for sure. We all have many opinions on how to deal with problems. Your grafting to the disease resistant wild seedlings started out intentional. In my case the house we bought had one small wild pear seeding close to the property line. The first winter I put it into a container with the intentions of making one graft with a resistant pear. Over the winter I as you did started thinking about grafting to higher limbs with several resistant varieties, thinking somewhat like you in that if fireblight hit I could save my tree, have cross pollination, and an extended harvest. My system was not perfect but for me with limited space it has worked well. As of now I have no fireblight. The trees now have two limbs of Orient, two of Ayers, one of Moonglow, and one that was believe to be Hood (it is actually a smaller round pear that appears to an Asian type). This is the first year that all the varieties had fruit. I picked the last one today and it has been a great ride. I could not leave well enough alone so I have also started adding some trial apple varieties to the pear tree (got a few apples off it this year. I donâÂÂt exactly know where IâÂÂm going with this but I like the fact that you like trying different methods. Bill

Bill that sounds like a fun project and based on the varieties you chose it sounds like you did plenty of research. Those are all very fire blight resistant varieties. I'm growing one Fruit cocktail tree which I'm embarrassed to say is more of a way to grow grafting wood for the following year than to grow out for fruit. I like my grafting wood to be all new growth so I take a mature wild pear cut the top off and graft on some small twigs of hard to find wood. I go back the following year when there is several feet of growth and graft 5-6 trees off that one.

Any new developments in fireblight cures?

I am so tired of losing plants to this.

I have tried everything from pruning to copper, sulfur etc. Unfortunately streptomycin is not available to home gardeners in my country (Malta). I found a study that mentioned LMA ("a potassium aluminum sulfate") as a fairly successful treatment but I have no idea where to buy that.

https://link.springer.com/article/10.1007/s42161-020-00694-0

I live in a city and I blame the pigeons for carrying this plague to my rooftop garden. I can't control the pigeons, they will always keep coming back, carrying all sorts of bacterial and fungal diseases.

I feed my plants organic but when it comes to bacterial blight I am willing to try anything. If it means spraying weekly or even twice a week I could manage that.

It is just so disheartening to have to throw out plant after plant.