I try and spray at the white bud stage (flowers just showing a little white but not fully opened). If not able due to weather, then I spray at petal fall. I use Chlorothalonil or Captan. Never got brown rot on my peaches. I did get some on cherries one year just as they were ripening (very cloudy wet week).

Some do spray Captan again closer to when the fruit is about to start ripening to hopefully prevent brown rot on the ripening fruit. Spray about 10 days before your normal expected ripening dates from previous years harvest.

You should look for Monterey Fungi-Fighter, it is much more effective for brown rot than anything else available to the home grower. If its not at your local nursery get it from Amazon or other online store. Spray when you see the rot, or when you expect its about to show up.

Monterey Fungi-Fighter is discontinued. What would be your next best choice? I had severe rot on my cherries and plums last year. I wasn't able to spray often last year - hoping to have a better schedule this year. Thanks.

Try Bonide Infuse. It's the same active ingredient as Monterrey Fungi Fighter. You can get it from Amazon.

I just looked up the label for Infuse on Bonide line. Interesting that it controls/prevents brown rot but has a warning NOT TO USE ON STANLEY TYPE PLUMS. I presume this means do not use on European prune plum types? Just Jap plums and American hybrid plums? I wonder if it is a burn issue on the skin of the plum like I can get when I use Captan on my Stanley plum early in the season.

Anyone ever use this product or Monterrray Fungus Fighter on prune plums and have a problem?

I think MFF had the same warning. I read somewhere that Stanley plums get deformed or oblong when sprayed with MFF. The only Euros I have are Stanley and GG but neither have fruited for me. So i can't speak from first hand experience.

I just looked up the old label for Monteray Fungus Fighter and for Bonide Infuse. What is the PHI? I could not find this info on either label. Since it is a systemic product, when should spraying stop so fruit is safe to eat? Just wondering since brown rot when I did have it one year on cherry happened just when the crop was ripening. The weather was cloudy and wet a that time and the brown rot spread like wildfire.

If you could find Indar in small quantity, it is better than MFF against brown rot.