The problem with shot hole is that it can be caused by a fungus (Coryneum blight) or by a bacteria (bacterial spot) or by Captan burn (although I’ve never seen this on my trees).
Thank you all for your reply! I think I figured out what was wrong with my plum tree – Captan burn.
I looked up my note, it was 4-5 days after captan was sprayed when I first notice all the hole on plum leaves. I remember seeing all the red spots and holes even on the plum branch I grafted to the peach tree while the host peach tree leaves are relatively intact.
So if it’s fungus or bacteria, it should also infect the host peach tree, right?
Mamaung, Thank you for showing me how to bag the fruit! One of my pear tree has 12 fruitlet, I can try to bag those. Can’t imagine bag all the peaches, God knows how many hundreds of them. It will kille me.
Mamuang, your choice of variety are much more sensible than mine. When it’s peach season, I spend hours and hours canning the peaches, making jam… It’s crazy:-(
Have you thought of (or heard of anyone) combine use of surround and some pesticide? I wonder whether that will work. It’s not total organic, but if it can reduce the use of pesticide and if I don’t have to bag the fruits, it will be good enough for me.
I used Triazicide in my second coat of Surround. First coat went on with blueberries still in bloom so I held off. I added it to second coat with Immunox too - mostly for the apples that I sprayed with the same tank I used on peaches.
I try to lean toward less chemical when I can.
The only thing I have mixed with Surround is sulfur. I think mixing Surround with insectcide defeats the purpose of going organic.
I could see using Triazicide at petal fall right around the time PC hits hard for a spray or two. Then switch to Surround to cover later when pest pressure is less. This way, you do not have to spray too much chemical.
Until this year, I sprayed Triazicide and Immunox at petal fall before I started bagging. I can bag to protect fruit but I need Immunox for CAR and scab. It is very effective. I only spray once or twice. I may try sulfur more this year.
I try to read up Scott’s practices and either copy or modify what works for him to my situation.
Well said. That’s exactly how I am viewing this approach, Mamuang.
Brethil,
After saying that, I am still worried about OFM. It has up to 5 generations. Last year, I saw shoot damage into Aug/Sept. I fear them on peaches and plums. OFM can do real damages on them.
I can either continue to spray or bag. I choose to bag. My trees are short (6-10ft). So , they do not produce as many fruit as a full size tree. I also thin rather aggressively. So, I do not have as many fruit as one may expect.
I agree and I have the same concerns. OFM is here in big numbers.
The long answer for me is that I am still very much finding my way as to what works here for me, on my site. The first step for me was reading so many helpful posts (many of Alan’s) on CAR spray schedule, because I am in suburbia and that enemy is everywhere. Cedars of all kinds every way you look.
Bug-wise, the OFM found my peach tree the very first year I planted it, and hit the shoots hard though there was no fruit. Thus I had to work up the courage to knock them back. I think I have PC because I am sure I have seen the crescent scars on my large apple tree fruit, which I think is a Spy and was untended for many years. So in this year, my first year allowing my peach to fruit, I want to hit the bases I think I must and have seen present: the Surround for me works into a spray schedule as a wonderful adjuvant therapy, like an additional physical barrier to the chemical spray program. I also now have bagged the peaches that seem to be my best keepers. Right now that’s not many - in coming years, with three trees in fruit, it may be a lot. Like you my trees will be kept short for that reason - I would rather have smaller yields which are plenty for us than have more fruit than I can tend by myself.
So in the first spray, I didn’t want pollinators injured seeking the flowering blueberries, so I went with plain Surround. Then post-blue-bloom I added in the Triazicide and also treated my apples with Immunox on the second pass of Surround - thinking of that dratted PC and the most barriers I could put up.
The question is … where I go after this. 
My few peaches are bagged; apples I can continue Surround with, and I have apple-maggot decoys up. I have OFM traps up for surveillance: I’m debating if I can make some sort of shoot-targeted spray/Surround slurry to use once they become active against peach shoot tips in later season and try to protect them. Or is bagging shoot tips something that may make sense in a small tree? This is what I think about a lot.
Sara…I for one (no. I’m definitely not an expert or anything close) would be willing to bet absolutely anything save for the lives of my children that that IS NOT Captan burn.
I’ve never been surer of much else.
There is absolutely nothing that points to the damage in your photos being related to chemical burn. I’m 1000 percent certain of that.
It’s most likely either bacterial spot or shot hole as others have suggested. That very same thing infects my damn peach every single year. I never once sprayed Captan here where I am now till this year. There isn’t one shred of logical evidence to suggest Captan burn or any chemical burn for that matter…the clinical evidence just isn’t there.
I’m always cautious to make strong comments here because there are so many smarter, more knowledgeable folks here than me, but in this case I’m not the least afraid. I wish I could tell you precisely what it is, but I’ve had some difficulty distinguishing diseases of stone fruit.
I can however say with confidence that it isn’t Captan burn.
Brethil,
I’ve tried to spray fewer chemicals. I also don’t mind some blemishes on fruit (worms not included).
Here’s what I have done:
Apples, peaches - bagged. I am so good at bagging with plastic bags these days that I actually have fun doing it (nuts, I know) Using footsies to bag peaches is a pain re. tying them. I use plastic bags on peaches as a trial this year. If they work, I’ll bag peaches with plastic bags.
Pears: Spray one or two cover sprays with Surround. Pears are tough to destroy. I’ve seen PC and OFM scars on them. Most are only skin-deep. I do bag with sandwich bags on the ones I have only a few like Harrow Sweet, to be sure.
Plums: this year is an issue because there are so many of them and the small size of Shiro makes bagging a real challenge. I need to come up with a mass-protection method without chemical if I could.
Cherry: No protection. I’ve gotten tired of them crack and rot as it rains right about picking time every year.
The chemical I rely on is Immunox for scab, CAR and other things fungal-wise. It’s really effective. This spring, it’s was so dry. I only sprayed once recently. That’s that.
This year, I will try Monterey Fungi Fighter on late peaches and cherry. Those have gotten increasingly bad brown rot every year.
Again - I think it’s all in the attitude 
I like the idea of spraying fewer chemicals. I don’t mind getting less than perfect fruit (bagging give you perfect fruit) and I prefer quality (taste-wise) over quantity so I thin more and have fewer fruit.
I could change my tune and started spraying like mad when all my 25 fruit trees are in production!!! 
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I am bookmarking this post. Like a road map for me going forward. 
Thank you.
I went and tried plastic for peaches this year; I made a lot of vent holes in them and used pipe cleaner to make them into a ‘dome’ shape which anchors them to the tree and I hope gives more air movement. I used plain bags, no ziplock, as the pipe cleaners are the ‘lock’ to the branch. Scott posted a link to gusseted bread bags recently and I like the look of those. I put my bags on after spraying when peaches were just a bit less than dime size. So far, I see no damage. Am debating switching to paper bags though…rot issue does worry me. A lot.
I am holding off the temptation to get more cherry. I have a single Carmine Jewel I am growing against the shed wall facing south so I can easily tent it once it fruits. I have heard too much about cherry cracking and headaches.
I do want to chemical spray the least that I can to get edible (not necessarily perfect) fruit. I was determined to be 100% organic and just engineer barrier solutions … until my hard-won fruitlets formed. And then I suddenly felt like a lioness defending cubs, which sounds less like fruit growing and more psychiatric but there it is. 
My hope is to have this year’s program work, and then dial down to more precise and targeted sprays. Ideally I would like to get to two insect sprays, maybe even one (keep dreaming). But ‘one’ would likely need Imidan and I’m not sure I can get that OR have my neighbors tolerate the odor. So sticking with homeowner brands maybe I can get to two, and keep the Surround and bagging program going all season.
How is Asian pear in terms of some bug scarring but edible, salvageable fruit? I only have the one Asian (20th Cen.) and they are so hard and crunchy that’s why I went that way.
I wonder in the case of your Shiro if whole branch bagging is somehow a possibility. Question of row cover maybe…if it lets enough light in to the leaves. (?) So many fruits to protect.
For the shoot tips the simplest solution is to just prune them out. I prune out hundreds of shoot tips every season, it helps keep the overall numbers down. Spinosad (a virus) is also very effective and I spray that on shoot tips during the early shoot infection periods. Surround also helps, it provides friction. Around egg laying time Bt can be very effective as well, before the worm is inside the fruit or stem it is vulnerable.
It took me several years to figure out all the subtleties of how to protect my peaches without bug killers or bagging, but if you keep at it you will keep learning and improving.
Forgot about Spinosad. I’d have sworn I bought a bottle last year but cannot find it now.
I am very lazy when it comes to monitoring these pest activities. I should try to be better at it so I can time my spraying correctly and more effectively.
I’ve considered the bread bag method since I read Alcedo’s post. I am going to buy bread with that kind of bag. I really don’t care for bread (I like rice ) but want a bag to try. I hope I could mass-bag my plums with a bread bag. Bagging a whole branch is iffy for me because my plum trees have long, arching branches.
We all should share our ideas about growing fruit organically. Who knows? We may come up with such a good idea that even Michael Phillips could put it in his next book!!!
Brethil,
As for cherry, I must be one of a very few who don’t care for it. I love cherries. Bing and Rainer kinds. Don’t think they’ll do well in New England. I have Black Gold, Vandalay and now Black Star (not sure what made me by more).
BG is productive. To me, it tastes fine. I had two lbs of them last year. The rest cracked and rotted. I said it before I like crunchy, sweet cherries like Bing. I do not know if I let my BG stay too long on the tree. It’s a bit softer than I like (not totally soft).
Never had a Vandalay. Lost them to cracking, rotting and birds every year. One year, ALL of them cracked when we had rain after over a week of dry weather.
Cherry has aphids, canker, leave spot, cracking, rotting, bird problems. It is not really worth it for me. I almost took them out but they have a very nice open shape, short and wide. I leave them be for now.
I have a Danube for sour cherry. It’s so stingy re. fruiting. This year, it has maybe, 20- 30 cherries on it (as opposed to BG which as loads of cherries). I’ve graft a North Star on it. I’ll keep adding a few other sour cherry varieties for a fun project. The only issue I have with my sour cherry is birds. So, I’ll call mine a low maintenance tree.
Appleseed,
I t-bud a plum to one of my mature peach tree a couple of years ago. this year that graft was a few inches long when I first discovered the leaves of that grafted plum are full of holes, while the host peach tree leaves are relatively intact.
if it’s bacteria or fungus infection, wouldn’t you think peach leaves will be infected too?
Or maybe peach leaves are tougher than plum leaves.
Next year, I will have a controlled experiment:-) the grafted plum branch will get captan along with the host peach tree, while the plum trees will be without captan spray.
Captan can burn holes in leaves. I’ve seen pics of peach leaves with captan burn and they are full of shotholes. I can’t find any pics of peach leaves showing captan burn right now. I found one with apple.
In the pic the dark spots in the apple leaves haven’t fallen out, but I’ve seen pics of peaches were the necrosed tissue fell out showing shothole.
That said, my guess is your plum is probably showing bac. spot. Many plums are very susc. to the disease.
Olpea, I looked at the photo you posted and I’m not convinced. They seem to be unsure themselves. It sounds like they too settled on Captan burn due to their ideology that if it were disease it would have spread and been on other leaves as well. Fair enough, but were those damage leaves also the only ones they sprayed with Captan? Using their own logic in their own caption how would they then explain the fact that the other leaves are 100% blemish free? The only explanation would be if they could say the damaged leaves are the only ones that were sprayed. They are not saying that because of course, that’s not what happened…all of it was sprayed.
I know you’ve seen disease damage this way…of course you have, even I have and I’ve seen it a lot actually.
To go a bit further, that damage looks nothing like what Sara posted photos of.
There are photos of Captan burn on google images and just as literature indicates it is exactly as one would guess, it is displayed as a brown burn at the leaf margins/edges and also in areas of the leaf where there is a cup or natural pooling area. NONE of that appears in her images.
Furthermore, the fact that you’ve had difficulty sourcing a single photo of Captan burn on peach leaves ought to maybe speak to the frequency of it’s occurrence, should it not? I don’t have any experience with Captan beyond a few sprays, but I have sprayed a load of Sulfur and I see it blamed for damage that it didn’t cause as well. It must be exceedingly rare even on varieties in which there are warnings for. The perfect storm of temperature, humidity, variety, timing, and spray concentration must have to be just right for damage to occur.
Sara posted just days ago about the fact that her husband was spraying half strength Captan.
I could have in any year shown you leaf symptoms identical to those in her photos. I cannot do it this year, because it has not manifested itself yet. Ironically enough, the difference may in fact, be due to Captan that I don’t have this damage…yet.
Again, I’d bet nearly anything that the damage Sara posted had absolutely nothing to do with Captan.
Sara, no, I wouldn’t think that at all. I mean we’re talking not just two different varieties here, were talking two different fruit types. I don’t find that at all unusual or hard to fathom. I mean, I get what you are saying and it is notable and everything, but no, I don’t find it odd in the least bit.
Let me ask you Sara…when hubby sprayed the 1/2 strength Captan, did he only spray the T-budded plum, or did he spray the whole tree? I’m thinking he sprayed everything…right? If he did, then the same logic holds (in this case though it would be even more logical…well, sort of), wouldn’t the entire tree, host and graft be affected equally? The truth is, maybe, maybe not, but although chemical burns can be selective, so to can bacterial or fungal infections and either of the latter is exponentially more likely.
Sara, out of curiousity, what are the varieties of plum and peach in question?
Also, I think it’s no small thing that there are no specific warnings at all that I’m aware of on the label concerning sensitive varieties of any specific type of plum on the Captan label whereas selected apple varieties are freely called out by name.
If I could say precisely what your problem is then I’d be doing something. I’m aware that saying “it definitely isn’t this”, but “I don’t know what it is” sounds kinda lame. Thing is, even Kearneysville research station states that stone fruit diseases are often difficult to distinguish because when they succumb to one they are often then (in their weakened state) infected by another and their symptoms run together.
I’d bet anything it’s a fungal or bacterial issue or both.
Apple,
I’m essentially in agreement with you. I’ve sprayed Captan at the max. rate under all circumstances and never seen burn (that I recognized). I also doubt Sara’s damage is the result of Captan. My only point in my posts is that Captan can cause shothole. I’ve seen pictures in the literature from people who I think should know.
I haven’t tried to duplicate the damage of some of the photos I’ve seen. I suspect it occurs at rates beyond labeled rates in peaches. I know Alan has mentioned he has seen Captan burn with young tender apple leaves.
This following link has an article about Captan damage. It was written by Dave Rosenberger, plant disease specialist at Cornell (since retired). He wrote a monthly article for the Cornell apple grower newletter (Scaffolds) for years and really knows his stuff.
He also mentions spotting caused by Captan. He writes the young leaves are the most susc. That doesn’t explain the photo I posted of the above apple leaves, unless they sprayed just some of the leaves to show the difference in the photo (which I doubt) based on the caption, so you could be right that the photo posted in the Purdue newsletter is not a picture of Captan damage.
I have seen peach photos of Captan burn and along w/ shothole, there is damage at the end of the leaves where the heaviest concentration of Captan redistributes on the leaves. I think it can be hard to distinguish from bacterial spot or fungal shothole because water or dew also congregates at that point on the leaves and it slowest to dry out making that the most susc. portion of the leaf to those diseases.
Running a test to determine the effects of Captan damage would be easy enough if someone wanted to. Simply spray 1/2 of the tree with Captan and the other 1/2 no spray (control).