I underestimated several of my peach ripening times, so I stopped spraying them quite a bit earlier than I should have (a few trees). Well, now that they are finally getting close to ripening, I’m seeing brown rot on all the peaches that get bird pecks or for other reason have issues. When I spray correctly, those peaches can rot but never show the infamous brown-rot brown mold. But thanks to me having not sprayed them for quite a while, they are covered in brown rot when they go bad.
Captan is not the most effective thing against brown rot, but I’ve felt it does help with it for sure. THe preharvest interval is 3 days, and that’s about when my peaches will be right. I can make sure I wait the required PHI so this post isn’t about the safety questions- I’m using this fruit an am comfortable as long as I meet the label reuirements.
MY question is, do you all think it will do any good at all to spray them this late in the cycle? Remember, they have gotten several rounds of Captan and Myclobutanil since shuck split, and that would normally have stopped brown rot 100% if I do the last one 14 days before harvest (the myclobutanil PHI). But brown rot is at hand now, and Captan is all I know I can use this close to harvest.
What do you all say? Complete waste of hard work, time, and money, or a worthwile chance to hold brown rot at bay? Thanks for any input
I’m fighting it myself and have sprayed harder this year than ever. If you have undamaged fruit I would spray and remove rotted fruit. Might have to skin everything, but better than total loss. I personally know what total loss feels like. I am at the point where I am ready to buy bulk fungicide and spray after every rain.
I was just looking at captan and it also says not to spray near harvest. That’s why I said skin them to get around that.
ha! @mamuang says (and documents) that Captan has 0 PHI. @Robert says you saw that captan says not to spray anywhere near harvest, and my google search showed a 3 day PHII!!! (I forgot the source) so this is harder than I thought.
But Tippy has a reputable source and i can probably do 3 days anyway, so as I said originally, I am comfortable health wise trying captan and picking in 3 days. What I am still wondering is if I’m wasting my time, money, hard work, etc. Just don’t know. Common sense tells me that using a fungucide to prevent a fungus that isn’t yet VISIBLE just might work, but my common sense and reality often don’t merge with fruit growing ! haha
@Robert it does sound like you know that pain of total fruit loss from brown rot. I absolutely have too!!! Its so heartbreaking to see them get that horrible brown mold-looking fuzz and then rot- just as they start to get ripe. But for probably the last 4 years I’ve sprayed Myclobutanil AND Captan every 2 weeks until 2 weeks from harvest and absolutely haven’t seen a TRACE of brown rot even on rotting fruit. Success with those 2 has been amazing…until I blew it by stopping my spraying too early this time!
OH…Tippy, I don’t have Chloro and won’t have time to try and track it down tomorrow, and I pretty much have to do this immediately if I’m going to do it at all because those peaches will be ripe (and maybe rot) in just a few days. I only know I’ve got a problem because I started seeing my damaged fruit show brown rot today.
Anyway, I guess its worth the money, effort, time, etc to go ahead and buy, mix, and apply my captan and see. The fact that I have treated these trees a few times earlier gives me a little more hope than I can stop it now with a final last minute application, but I sure don’t know and its going to be a hard, expensive lesson either way.
Look at it more in terms of the rain. The more it rains the less effective your sprays are. It rains a lot here so even with sprays I still see some rotted fruit.
The confusion on Captan PHI results from some formulations have a 3 day PHI while others have a 0 day PHI. As I recall, and unless they have changed it, the 80% formulation has the 0 PHI, while formulations with less active ingredient have the 3 day PHI. Of course, your own formulation will tell you which PHI you have. The formulations with the 0 PHI have a 3 day REI, as I recall, so you can only pick with the proper PPE. But you can technically spray the fruit and eat it immediately with a 0 day PHI.
Chlorothalonil is indeed a good fungicide for brown rot (and a good many other things). However the label doesn’t allow use on stone fruits after shuck split. It can be used on tomatoes with a 0 day PHI, which is what I use it for during the growing season. It’s very effective against early blight.
In terms of your fungicide sprays. Yes I think a late spray of captan would do some good. It doesn’t have kickback activity, so it probably won’t prevent the spread of any fruit already starting to rot, but should help prevent other fruit from rotting. Just make sure the water is acidified before you add the captan.
Indar is the best for reversing rot. It will actually arrest the spread of a partially rotted fruit. The problem is that it’s really expensive for a backyard grower. I don’t have a price in front of me, but it runs between $300 and $400 per gallon. A gallon of Indar will treat 32 acres at the 4 ounce per acre rate.
You might consider Elevate fungicide. It’s supposed to be a novel chemistry which has good control of brown rot. It’s too expensive for most commercial growers (something ridiculous like $80 per acre) but it comes in small 2 lb. packages which only cost about a hundred bucks. One package will do a little more than an acre at the 1-1/2 pound rate. It’s expensive on a per acre basis, but cheaper to buy because of the small packaging, so it sort of works better for backyard growers where cost of the spray per acre really doesn’t matter, if that makes sense. I doubt Elevate has the kickback that Indar does, but it’s supposed to work well against brown rot.
I have used Elevate for a couple sprays. As I recall, I think it worked well. I still have a package or two left I probably need to just use up.
There have been previous posts of this very subject. Captan’s efficacy is reduced significantly if
your water is basic. The PH of my water is fine, so I never got into how to acidify the water.
Captan breaks down in water that is basic. Normally city water is basic so pH adjustment is required. See this post for details of why pH adjustment is important and how to do it.
Rural well water pH is highly variable. You really need to test and find out what the pH is. If your well water has a pH of 8 in 10 minutes half the Captan is destroyed. In 20 minutes 75% of the Captan is destroyed.
I found your thread, Kevin, while I was searching brown rot on stone fruits. I don’t want to start a new thread which will be pain to go through each short thread when someone else does the word match search. So please allow me continue your thread and discuss this topic here.
This year is pretty dry in general and I stopped spray fungicides in mid summer. I thought everything looks good. Then I found one rot plum few weeks ago as Shiro started to ripe. I thought it was yellow jacket’s doing so I just pick it off the tree and put out traps. Then I found one peach , more peaches, as the day going on till whole branches of peaches all molded in different stages. I sprayed Captan but it didn’t stop brown rot. The mold continues as more fruits start to ripe. Lesson learned
I feel your pain more than you know. This year I got hit hard by brown rot and its just heart breaking. I walk through my orchard and see PILES…I mean HUNDREDS of peaches laying under my trees that look just like those in your photo, or worse. I would much rather have just lost all my blooms to late frost than to have watched them grow all year and cared for them, only to see them all get covered in the Brown Rot “mold” and fall to the ground just days before they would have been ripe.
BTW…there is actually a newer and better thread to discuss this problem. The title is misleading but it ends up being a good thread about brown rot. I think its one of the best threads ever on brown rot. Its here:
