Has anyone seen this?

I found this damage on two of my trees. One is an Aprium and the other a Pluot and they are next to each other. No other tree whether hybrid or not seems to be effected

All have been sprayed regularly with Indar Myclobutanyl and Captan.

It looks like some kind of scab, but I have never seen scab in such blobs and the friit are cracked

1 Like

Was it dry? Then lots of rain? It looks like they cracked from rain and then got infected.

I can’t tell what caused the damage. There may be a few things going on at the same time. The cracking could be from dry spell followed by rain.

The dark spots don’t look like typical scab. I wonder how much those spots were caused by fungicide burn due to several days of very high heat we experienced last week.

Can you cut them up and show us the inside. It’s good to find out if the damage is only skin deep. How the leaves of these trees look? Leaves could give us some clues.

By the way, @thecityman is facing an unexplained plum disease, too. He suspects plum pox but the damage on his fruit does not look like yours. Plum pox shows sign and symptoms inside the fruit, too.

I wonder if others like @scottfsmith, @Jose-Albacete could chime in.

1 Like

Hi mamuang,
I do identify Michael’s trees disease, but it’s not good news.
Those damages that appear
in the fruits they are due by the bacterium Xanthomonas Arboricola pv pruni.

I am writing from the mobile phone, in a while I will send you information from my computer.




The damage appears to be surface damage, not counting the obvious cracks. Although, this might be early in the disease and maybe it has not had a chance to get deeper into the fruitlet.

Also, I googled “Xanthomonas Arboricola pv prun” and found a Penn State Extension article that tslks about this. I will look more deeply into it and am anxiously wairing for additional info responses from @Jose-Albacete.

Also Iattach a photo of the leaves


1 Like

Most of my cots and nects have lesions like that. During the heavy rain, they oozed copiously

Hi Michael.
I was precisely going to request some photographs of the leaves, to corroborate the diagnosis, and indeed it is the disease commonly called bacterial stain of the stone fruit, caused by the bacterium Xanthomonas arboricola pv. pruni.
It attacks all types of stone fruit including the almond tree, and unfortunately it is proliferating a lot.
Fortunately, it is not as deadly as other bacterial diseases, and with good treatments it can not only be controlled but it can be eradicated.

Take a look at this document (there are a million documents in Spain, perfectly describing this disease).


An image


The control currently goes through the use of copper compounds and sulfur.
But, (fortunately this one but it is good), fighting methods with phytofortificants are being carried out, and they are giving excellent results.
I do not want to venture to recommend a product, without first having read a lot of literature about it, but I think there are a couple of companies that are very advanced in terms of phytofortifying products that are specific for this bacterium (I think one of them is the Certis company) .
Let me inform myself well , and I recommend a good product to try to fight against that bloody disease.




Thank you ever so much


I have seen leave damage or small damage on fruit. Your fruit got it badly. Must be the susceptible varieties. You have probably seen this article.

Stone Fruit Disease - Bacterial Spot.

What do you plan to do? Spray or remove those trees?


I will try a vigilant planned spray program

@Jose-Albacete indicated that there may be a way to control and even eradicate this disease.

I want to avoid removing the trees because these fruited this year whereas other hybrids were “no shows” even thiugh some carried a good flower load.

I want a spread of varieties so that I get at least some protection against different yearly weather patterns.


1 Like

Hi Mike,

I had bacterial spot on several susceptible varieties of nectarines in my former orchard in Delaware. If it rains when temperature is in the seventies or above, my trees where surely going to show symptoms. One of my trees lost 50% of its leaves before because I did not spray prophylacticly. All spraying is prophylactic, no kickback effects. Two sprays got it under control for me: Copper octanoate (lowest label dose, to minimize phytotoxicity) or oxytetracycline (I included sticker in all my spray mixes). I start spraying when spring temperatures approach seventies and when rain is forecasted. Two to three sprays in spring/early summer were typically enough for the rest of the season. You cannot completely avoid copper’s phytotoxicity, but little injury from copper was better than major tree defoliation. Note that pluots and apriums seemed more sensitive to copper’s phytotoxicity than nectarines. I prefer oxytetracycline because it is not phytotoxic, but I don’t have enough experience with it to judge if it will always be enough on its own (I only used it for one season).


Great info. Thanks

Hi Michael, you asked me by private message if I had found any new information.
And the answer is yes " .
I have a study from the Polytechnic University of Valencia (It is one of the good universities for agricultural engineering in Spain), which brings us new information about it.

I do not give you the complete document ( it’s like a bible of big ) , and I focus on what is really important, since in terms of the chemical fight against this disease, in the European Union only cupric compounds and sulfur are authorized (the European Union is increasingly restrictive with the chemical), and in the field of phytofortifiers, treatment with glucohumates is still in the development phase.

So we will focus on the advances with the biological fight, where there are important advances.

This is the cropped document (the important thing).

LÓPEZ - Especies de Xanthomonas causantes de enfermedades en frutales de hueso y almendro diagnó…(1)-80-82.pdf (301.8 KB)

This is the text translated into English.

Biologic control

The fact that the use of chemical products is increasingly limited in EU countries has led to an increase in the study of potential biocontrol agents. Several bacterial strains have been described with an antagonistic effect on X. arboricola pv. pruni. In tests carried out in peach and nectarine plantations, it was observed that a strain of Pseudomonas fluorescens had an enormous inhibitory potential on X. arboricola pv. pruni leading to a reduction in the incidence of the disease (Biondi et al., 2009). Similar results were obtained in tests carried out with a strain of P. aeruginosa (Silva Vasconcellos et al., 2014) and with this strain, an effect on the exopolysaccharide production of the pathogen as well as changes in its cell morphology was observed. The antagonistic capacity of two non-pathogenic strains of X. campestris (AZ98101 and AZ98106) has also been studied in field trials on various peach cultivars, observing a significant reduction in the incidence of the disease (Kawaguchi et al., 2014). The efficiency of several strains of

Lactobacilus plantarum for the biological control of this disease (RosellĂł et al., 2014).
The use of phages as biocontrol agents of X. arboricola pv. pruni has also been described. Zaccardelli et al. (1994) verified that certain phages obtained in infected peach fields gave good results for the control of the disease in peach trees. However, its use on a large scale can present a series of drawbacks, such as its poor survival, its inhibition by chemicals commonly used in cultivation and the possibility of generating resistance by the pathogen (Randhawa and Civerolo, 1986; Zaccardelli et al., 1992).

I haven’t done much research on the availability of the recommended strains (Pseudomonas Fluorescens, Pseudomonas Aeruginosa, Bacteriophages, etc …).
Just by looking at the store where I usually shop, Pseudomonas Fluorescens is available.


Michael, now you know a little more about how to fight this disease




Thank you very much

You are a very thoughtful and valuable asset to this forum.



Hi Mike, it’s a real pleasure trying to help you.
Unfortunately bacteria and viruses are “the unfinished business” in the fight against diseases of fruit trees.
I would like to have given you news about a miraculous and immediate remedy, but it is quite complicated.

You’re not alone .
I have 7 lines dedicated to cherry trees, and each line has 40 trees.
The first line begins with the first 5 varieties of cherries from the collection Sweet the Alma Mater of the University of Bologna (a true wonder of cherries).
I have been taking care of those cherry trees for 7 years, and suddenly the first one, (the Sweet Valina variety) without any symptoms of anything, has completely dried up “sudden death”.
There are no symptoms of holes in the trunk, to think of a big-headed worm attack (Capnodis Tenebrionis), it has been perfectly fertilized, watered and cared for like the rest of my trees.
And yet it has dried up “by the work of the holy spirit.”
I have no bacteriosis problems or xanthomonas syringae in my orchard, the rootstock is totally suitable for my land and all the trees in my orchard are perfectly fine, but this tree has dried up.
I can’t do anything other than re-graft it, and luckily I have refrigerated cuttings of this variety, so it’s not a problem.
But it is a real shame to see a tree whit 7 years , that a few days ago was perfectly fine and is now dry.
Things of nature.