SOS Pear Disease ID and Treatment?

Hello all, after rabbits destroying 60% of my orchard one of my remaining pear trees started showing some concerning symptoms and I. Am. Worried. See the below pictures.

I am having trouble diagnosing this one as there are many pear diseases which produce these black marks. Anyone have any idea? I am dreading if it’s fire blight because it’s on many leaves all around the tree. Thoughts? Any idea on treatment?


My pears have similar things going on every year in the spring time, on leafs and flower clusters. But it’s not wide spread, just here and there. I think it’s a blight. I just pick off the infected leafs and flowers and throw them in the garbage can. Hope someone else will chime in to help make a conclusion


I hope so too. It’s beginning to appear that I may not have the best of luck with fruit trees and should just give up.

In my experience fireblight affects much more than leaves. I don’t see any traces of it on stems, etc.


Interesting thought. There are also no cankers I can see or shepherd’s hooks, although it is very early. It had what looked like leaf spot last year, but this doesn’t seem like that. I wondered if it’s pear psylla or something else, but I cannot seem to identify whatever this is.

@mamuang , @scottfsmith
Can you ID this?

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Any necrotizing tissue in pear turns black, making it difficult to ID.

Here’s a thread on early fireblight from @clarkinks . Like @Richard, I share opinion that it doesn’t look completely similar to yours.

Just to make sure, is everything under the white tree guard okay?


Fireblight can take many different forms. That said I have never seen it looking like that. But I also don’t have any better idea besides fireblight.


I’d like to see how stems of those leaves and fruitlets look, too.

I have not seen that type of damage before, either. However, if the damage moves into stems, it could be fire blight.


Out of all the stems I see, only this one looks suspect



That looks much like a harrow type pear which are highly resistant to fireblight. Harrow sweet frequently has a pink and white bloom that is similar.


I believe this one is a Parker Pear, which I understand is somewhat resistant as well.

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Unfortunately fireblight will be a problem if it is prevalent in your area. My solution would be spray with copper now. @scottfsmith said it correctly we dont know it is not fireblight and what else is it likely to be? Fortunately due to your dilligence of removing infected parts the disease was prevented from entering the tree thus far. Is this the trees first time blooming? If so that is when you typically see fireblight. “Due to the high susceptibility to fireblight, pears should only be pruned when dormant (winter-early spring) unless one is pruning out existing fireblight damage (spring) to prevent it from spreading further.” More about the Parker pear below. There are many positives about the tree but the negative is disease susceptibility. The treatment for pears is very inexpensive and is nearly the same for susceptible apple as shown here An early-season copper application will help avoid feeling “the blues” about diseases - MSU Extension

That looks like a smaller tree if so a simple spray bottle like this is fine

Concentrate like this is also available

" Parker Pear

Pyrus communis ‘Parker’

Description & Overview

Parker pear was developed by the University of Minnesota and released in 1934. The fruits are medium-sized, green, and often develop a slight red blush on the sunny side of the fruit. While most pears need to be picked at the green/ripe stage and then slow ripened off the tree, Parker seems to be ok when picked fully tree-ripened as it does not have many issues with core rot like other pear varieties. Picking at the green/ripe stage is best as they will keep the longest when refrigerated.

Core Characteristics

Wisconsin Native: No

USDA Hardiness Zone: to zone 4

Mature Height: 15 feet

Mature Spread: 15 feet

Growth Rate: Slow

Growth Form: Tree

Light Requirements: Full Sun

Site Requirements: Well-drained site

Flower: White

Bloom Period: Early May

Foliage: Green

Fall Color: N/A

Urban Approved: Yes

Fruit Notes: Excels for canning. The flesh is sweet and very fine textured. Fruit ripens in September in SE WI."


It bloomed last year (first year I had it). I have not pruned it yet because it is still somewhat shapely and was going to wait.

Random fire light strikes are tolerable; I think my main concern is that each branch has these effected leaves, including short 3-4 inch new branches. So, if it is fireblight, I can’t just prune it out and I likely have to remove the entire tree (which is depressing).

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Not remove the tree if you spray with copper once or twice a year in addition to pruning you could be fine in your area. The fact it bloomed last year and lived is good news. Worse case scenario grafting the tree over to a fireblight resistant variety is possible. I have done it many times on my own trees. As an example harrow pears frequently bear fruit a year after grafting. If you decide to change the tree over you will not lose the hard work which is growing the roots of the tree. Zone 4b is not known for big problems. A spray or two with copper once a year in the spring may solve all or most of your fireblight problems. It is not to late this year. We dont know its fireblight but it makes the most sense given the symptoms thus far.


I’m going to go with “not fireblight”. As far as exactly what it is, I don’t know. I’ve always called it environmental distress. e.g. too much water, too little water, frost damage, sun burn, wind burn, etc. etc. etc.

I would begin a spray program for insects and diseases.



A copper spray should not hurt a thing just in case it is fireblight. In zone 4b i do find fireblight issues like that unusual. That would be expected further south.


I agree.

I hit all of my pears and apples with copper and oil last week.


I sprayed them all with Michael Phillip’s holistic spray last weekend, but I’ll get them with copper this week. Hopefully that will keep whatever this is at bay. I’ll also keep an eye on it to see whether it worsens.

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In a previous post regarding a similar issue (New pear trees with black edges on leaves - #11 by 7catcmom), @alan mentioned Pear Psylla. Wondering what you all may think? The injury looks similar, but it seems too early for bug pressure up here…but maybe I’m wrong :man_shrugging:t3:.

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