Brown rot control in your fruit – organically.

Brown rot

One of my email subscribers just wrote to me and asked about brown rot in nectarines.  As I had just posted about my great nectarine crop, I thought it would be a good idea to share the reader’s question for the benefit of everyone.  Brown rot is a common problem that affects not just nectarines, but most fruit including apples, cherries and peaches.

Brown rot is a fungus (Monilinia laxa and M. fructigena) that infects the fruit causing it to rot on the tree, and can spread to the branch as well.  Damaged fruit are more susceptible.  Here goes:

Hi Matthew,

Thanks. I find your tips and chart very useful over here in Sydney. I have a question on my nectarine tree.  This is the second year in a roll that they suffered from brown rot. The rotted fruits hanged on and dried up on the now dead branches. I have cut off these branches and throw away any of the rotted fruits that I can find. Any suggestion as to the cure for this? Will Copper Sulphate spray help?


Hi Simon,
Thanks for your question and I’m glad you find the tips useful.  Thankfully brown rot isn’t a condition I have had much of a problem with in my trees, but it can be a real issue as you describe.  It sounds like you are doing the right things with pruning off infected fruit and branches.  You should also collect any infected fruit from around the base of the tree.  Don’t put them on the compost heap.  Either burn or place the affected parts in a plastic bag and throw in the rubbish.
In addition you can use Bordeaux mixture as a preventative.  You should spray as the buds start to swell in spring.  It is said you shouldn’t spray the mixture while the tree is in leaf, but I have done it in the past and haven’t seen any negative effects.  The ABC has a great fact-sheeton making and using Bordeaux mixture, though their measurements make a very large batch, so I would scale it down.
Also from a preventative point of view you should prune your tree to have an open goblet shape.  This will let sunlight and air into the centre of the tree.  This will help dry out the foliage and fruit faster, discouraging the growth of fungus, plus it will help the fruit ripen faster.  The RHS has a page on thisfor apples, but the principles are the same for other trees.I hope that helps.  Let me know how you get on next year.Matt


2 Responses to “Brown rot control in your fruit – organically.”

  1. Zoe says:

    Ahh! Finally a solution to treat the ‘brown slimy stuff’ that was eating my prize crop of cherries over the summer! Thank you for a very informative article.

  2. Simon says:

    Hi Matthew,

    Happy New year.

    This is just an update on the brown rot problem I had on my nectarine last year. Well, I did as suggested by you. That is, I look up the ABC gardening website and made the Bordeaux mixture by mixing copper sulphate and builder lime and spray them thoroughly in autumn. I was supposed to spray them again in late winter, early spring before the buds open but by the time I came back from an overseas holiday, it was too late to carry out a second spray. The fruits are ripening now and they are perfect! No more brown rot! Just in case, I am going to carry out another spray program this year to make sure I have it under control.

    Thank you for your advise.

    By the way, I also sprinkle a handful of Gipson salt around the tree trunk and my sour nectarine is now absolutely sweet!


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