Is there an organic anti-fungal to spray on peach trees to prevent brown rot from returning? And if so, when do i start to use it? thanks.
Jessaka, there is no potent organic tool to apply against brown rot. There are several weak tools which used often and with good timing relative to rains will make an impact. The three best things I have found are Serenade, sulphur (or lime-sulphur, it is similar), and Saf-T-Side oil. Basically every spray I do on my peaches I include one of these three with. Don't put oil and sulphur in one spray or within a week of one another (unless there was a heavy rain in the interim). For this reason I tend to mainly do the oil&Serenade combo -- you can put both of those in one spray. Don't use a different brand of oil, Saf-T-Side is a unique kind of oil that looks like sludge in the can and is more effective at smothering diseases. It is very important to regularly spray in spring, basically from now through May, to limit the initial amount of disease. Putting down sulphur before a rain to limit new spores and oiling to death any new spores after a rain is another part of the timing. I don't by any means cover every significant rain event and I probably should be spraying more; I probably average a spray every other week or so. Around fruit ripening time is also another critical time for sprays.
Additionally I have found many varieties to be overly prone to brown rot infections so for the organic grower in the humid east the best solution is to remove those trees - not only will you not get much fruit but they will greatly increase your spore count. I removed my half a dozen worst-offending peach varieties over the winter and I hope that will make this coming year much better for brown rot. Last summer was OK but many fruits did not last long on the counter.
Jes, because there is no controlled research on evaluating brown rot susceptibility on peaches in this country (maybe in Canada, because I know they look at it in the Harrow apricot series) you'll have to go on hearsay and trial and error.
Here's a little hearsay based on lots of experience, lots of sites, lots of seasons that I have to offer. Here in Z6 where most fruit trees are just starting to bud out this week (J plums and apricots last week) early varieties tend to not suffer from brown rot- especially those that ripen a week or more ahead of Redhaven. I mention the growth development of trees here so you can compare- further south varieties will have to be earlier ripening to get same affect.
As you go later in the season, I've found that it is often the older varieties that offer the best resistance, such as Elberta and Belle of Georgia. If you can find it, I've found Harcrest to be similarly resistant and a superior peach. It is fairly recent and from the Canadian breeding program.
As Scott will agree, I'm sure, you'll need to prune the trees very open and remove anything that begins to rot before it spreads to other fruit and into the wood.
If you decide to go synthetic you will probably get excellent results with lots less work with a product called Monterey Fungus Fighter which can be obtained on-line.
I use a similar product and generally never need to spray within a month of harvest to get rot-free peaches of most any variety I grow here, excepting, perhaps, peento (donut) type peaches, which in my limited experience with these varieties seem to be born to rot.
thank you both. i will print these out and let my husband read them. and in my other post on bing cherry trees, i am feeling so much frustration.
our peach and nectarine have been pruned well this year, but we were not able to pick all the dead fruit on it, but i got most off the ground. and last year i picked all i could see and reach off the tree. i feel like the ground around the tree is ruined now.
i could order from a catalog and get the kind you suggested and plant it out in the field next door.
I was just reading my Immunox instructions getting ready to fight CAR for the season. I see it is rated for brown rot. Any opinions about effectiveness? I know my wish for a one-does-it-all is unlikely to come true, but hope springs eternal.
A number of people in the MIDFEX group have been trying Immunox for brown rot. It seems to have worked well on my Stanley plums last year.
Cornell only recommends it for blossom blight stage of brown rot- their trials indicate it's not very affective against the fruit rot stage so I've never tried depending on it for that purpose (meaning I'm not speaking from actual experience. When myclobutanyl came out like 20 years ago (at least that's when I noticed it) it was touted as being affective against all stages of BR.