It's probably captan doing this. I have seen Chlorothalonil do this too. Both I guess should be used before leaves get big, or are even on plant. Seems new leaves are ok.

Thanx, Drew, It is limited to just a few leaves I will be keeping an eye on this to see if there is any indication of spreading which might indicate an infection of some sort

Mike

Mike,

It resembles bac. spot of my peach trees. That said, I don't have any experience with Captan or chlorothalonil burning, so I'll defer to Drew on that.

One thing I notice about bac. spot is that it is most prevalent on the lower more shaded parts of the tree.

I believe Captan also burns the tips of the leaves (where the Captan mostly collects) and I don't see any tip burn on your photo. But again, I have no experience with Captan burn.

Can I ask what variety of peach is pictured?

I have no experience with bac spot, so best to assume it could be that too! Any treatment options?

Hey does the bacterial spot appear on the stems too?

From MSU

Leaf symptoms of bacterial spot on peaches and nectarines are generally dark, small lesions, often clustered at the leaf tip where water collects during dews and rain. Leaf tissue around lesions can turn yellow.

Spots look red, no yellowing. So leaf tip tells us nothingt as that is where bac spot forms too!

This post was edited by Drew51 on Mon, Jun 23, 14 at 11:17

Olpea:

I'll get the answer after this weekend. I snapped the photo as I was leaving and i did not make a note.

I have a few and I don't exactly remember.

Mike

Olpea:

I'll get the answer after this weekend. I snapped the photo as I was leaving and i did not make a note.

I have a few and I don't exactly remember.

Mike

That is exactly what my peach tree leaves looked like before many on one tree dropped. It was old Captan in my tank that burned the leaves. Mrs. G

The treatment for bac. spot is either copper or oxytetracyline. Copper can cause some spotting and defoliation on peach, if used during the growing season, as can bac. spot, but some commercial growers still use copper because it protects the fruit from spotting.

I use oxytet because it protects foliage/fruit without any phytotoxicity. I don't always see bac. spot concentrated on the ends of the leaves. The photo above looks like a light case of bac. spot to me. The red spots will turn yellow and eventually necrose and fall out, leaving a shot hole (assuming it's bac. spot). Perhaps the thing I've noticed most about back spot, is that it affects the most shaded leaves lower in the canopy. The picture shows such a light case, I wouldn't do anything to treat it.

I have one variety of peach which gets bac. spot so badly, the tree will lose 1/2 it's leaves and the fruit is so badly affected, it will crack. But this peach tastes so good, I put up with spraying it for bac. spot, which completely removes any symptoms. The peach is so good, I made 3 more copies of this tree, and will probably bud a fourth this fall.

It's hard to say, but I don't get why after spraying here in 2 cases MrsG, and mes111 we get symptoms. I guess possible? I had the same symptoms with Chlorothalonil on Lucky 13 cultivar, one that is bac spot resistant. So I myself really do not think it's bac spot. No shot hole will form, the leaf will drop off before that happens. And yes all leaves yellow with time.
It would be nice to get a definitive answer here. I also sprayed my trees with copper a few weeks before, but anything is possible. Next time it happens to me I'm taking leaves in to a local private nursery that has diagnostic services. But I have no plans to use Captan or Chlorothalonil on mature leaves again. Chlorothalonil is for leaf curl, and I don't need to spray when it has leaves. Captan can be applied early too.
Olpea,you use Chlorothalonil right? Are you sure your condition is not burn?

"Olpea,you use Chlorothalonil right? Are you sure your condition is not burn?"

Positive. The leaf spotting was primarily on two cultivars. One I removed. Both respond with perfect foliage if sprayed with oxytet. I've not seen any leaf spot symptoms with peach, using captan or chlorothalonil.

One difference might be the overall vigor of the trees. I've noticed with tomatoes (which are much more sensitive to fungicide phytotoxicity) that healthier, more vigorous plants will tolerate fungicide better than less vigorous ones. I wonder if the same wouldn't apply to peaches.

I've never seen any burn/shot hole from fungicide on my peaches. Except for the two highly bac. spot sensitive cultivars previously mentioned (and a bit of spot on O'Henry) my peach foliage looks perfect year after year, despite numerous apps of captan (and sometimes chlorothalonil before shuck split).

Note this late application though. That might be the problem for whatever reason? Those products are usually used earlier, and I also noticed my problem, late in the year. On my product chlorothalonil is not supposed to be used past shuck split. I was thinking because of the fruit, and since I didn't have any last year, I used it anyway, and these symptoms appeared.
We do know it can occur with captan. the question is did it? Or is this bac spot? I really thought it was chlorothalonil in my case. As the nectaplum being only part nectarine, showed only light damage, all peaches/necs showed heavier damage. None on the Pluot.

I took some photos this morning of some of my peach leaves. These trees have been sprayed several times with captan with a sticker.

Notice the residue on the leaves, and the way the rain has washed the captan toward the ends of the leaves, but still no burn from captan.

I know captan burn can occur, but as I've stated, I've used captan for years, in all weather conditions, and never seen burn (yet).

Here's another pic.

This is the formulation I'm using.

Well to be safe, i would error on the side of it being bacterial spot, and treat with copper, the leaves are history anyway. You know you get these spots with low nitrogen too, so maybe fertilize too!

Olpea
As a follow up I checked today and whatever it was did not spread. Obviously it must have been a reaction to the spraying. The parts of the leaves that had the black spots are now holes. But agaon, no spreading. See the photos attached.

The two varieties.that were affected were Q 18 and " 4th of JULY" peaches.

Mike

And

Thanks for following up Mike. I guess it must have been Captan burn. As mentioned, I don't have any first-hand experience with Captan burn.

If the 4th of July peach is the PF1 (sometimes called 4th of July peach) then that's another indication it's probably not bac. spot. I have that peach and have never seen bac. spot on it.

Whew, thanks Olpea! I had the exact experience with the peach trees that were sprayed with Captan. First spots, then drop, and the leaves that remained with the spots, the spots turned to holes. I've now removed the captan from my mix and only use triaz. and immunox. Is that enough? What do I replace the Captan with? Many thanks as always, Mrs. G

Olpea

It is the 4th of July peach sold by Stark Bros.

I got it spring 2013 and it is growing.like a weed.
Having a devil of a time trying to keep it as as fan espalier form.

Mike

I looked on Stark's Website and their calling PF5b their "4th of July" peach.

I just planted that one in 2012, so I've not had it long enough to have had much experience with it.

Mrs. G,

Unfortunately there aren't many fungicides available in packaging size for backyard orchards.

For stone fruits Monterey Fungi fighter is a good one.

I'm not sure of any other good fungicides for apples in backyard orchards. Some people use sulfur for apples, which offers some scab control and control of summer diseases.