Preventing nectarine 'brown rot' and peach 'leaf curl'...

lucia_ca(z9 CA)November 11, 2010

Hi everyone!

I need to quickly learn how to best prevent and/or minimize nectarine "brown rot" and peach "leaf curl" for this coming year. Thanksgiving is around the corner, so I need to decide on my action plan asap. I have a dozenish peach and nectarine trees that all got "attacked" with fungii this year, due to the heavy spring rain fall (I guess).

I've researched solutions to this issue and have read UC Davis' IPM page, but I guess I need more layman's terms and instructions geared toward a home orchardist. Here are the general nuggets of info I've consolidated:

1 - I should spray dormant sprays 3 times: once at thanksgiving, once at christmas and once around the super bowl

2 - the spray should be a copper OIL (not soap)

3 - mixing the copper oil with a dormant oil might make it more efficacious

4 - I should be thorough about picking up all diseased leaves, mummified fruites etc. to minimize hospitable fungal sites

If infection does occur, I believe that I am to:

- heavily fertilize with nitrogen and epsom salts in summer to encourage a vigorous flush of new, healthy leaves to replace all the "fungii-ied" ones..thereby bolstering the overall health of the tree and helping it shore up its strength for the next winter's exposure. Is this right?

So here are my related questions:

1 - Is using copper oil and lime sulfur considered "organic?" By this I mean, can I still fearlessly feed my children this fruit or must I scrub it thoroughly to remove all chemical traces of said sprays?

2- Do copper oil and lime sulfur work in concert with one another or is it an either/or solution? If it is either/or, is one better for brown rot?

3 - What should a total newbie wear when applying these products to trees?

4 - What concentrations of copper oil and/or lime sulfur should I buy? ...and how much water should I dilute it with?

5 - Can I spray the actual blooms or fruit with either copper oil or lime sulfur or am I rendering the fruit unhealthful for human consumption at that stage?

6 - Is using Tea Tree Oil (2 T per gallon) effective? If this is used before budswell, is it considered the 4th application or does it take place of the 3rd?

thank you for all suggestions, referrals and advice!

----lucia, CA-SF Easy Bay Area, USDA9 /Sunset 15-ish

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I only spray with Micro-Cop (linked below, but sold at most nurseries and I think at Lowe's) because lime sulfur will damage apricots and my apricots are intermingled with my peaches. It comes in a package with "Stay-Stuck" to mix in with the concoction, so it will stick better to the branches. It is offered on organic websites, so it isn't very toxic, but be sure not to breathe it in when mixing or spraying. The mixing instructions are on the package. Be careful--the green color stains, and your sprayer will be forever green!

Your spray schedule is about right-on. I have had my early peaches start to break in January before, but if you get the first 2, it shouldn't be such a big deal if you miss January. Spraying after blooms break and especially after fruit forms does nothing to prevent the curl (they get infected breaking out--once infected, it's too late.) Another problem are peaches that won't drop their leaves. Here it is the middle of November, and I still have some varieties with green leaves going strong. Obviously unless I strip their leaves off, a Thanksgiving spray is not happening!

I have never used dormant oil, but I think you need to wait 2 weeks in between dormant oil sprays for bugs and sprays for curl.

Hope this helps!

Carla in Sac

Here is a link that might be useful:

    Bookmark   November 12, 2010 at 12:41AM
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Get plenty of copper sprays on before bud burst (up to 'pink ' stage) after that ...

Here is a link that might be useful: Fixing Leaf curl in season

    Bookmark   September 26, 2013 at 8:12PM
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And go over to fruit and orchard forum to get more details on these and other peach & nectarine advice.

    Bookmark   September 27, 2013 at 11:58PM
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