dmnorton at royaloakfarmorchard.com
dmnorton at royaloakfarmorchard.com
Thu May 8 10:27:28 EDT 2008
For an organic approach to scab, begin your control program as soon as you
see green in the apple buds. For the rains occurring prior to when the green
tissue is ½ inch long copper or lime sulfur can be used either just ahead of
the rain or within 48 hours of the start of the rain. Copper should be
discontinued at ½ inch green tip or russeting of the fruit will result.
Sulfur is applied every 3 to 5 days or prior to every rain from ½ inch green
tip until 4 weeks after petal fall. If you cannot spray prior to a rain,
use lime sulfur within 48 hours of the start of the rain. For summer disease
control and if you have Scab infected leaves 4 weeks after petal fall you
should continue sulfur sprays on a 2 week interval until harvest or the end
of August whichever comes first. Spray until leaves are dripping. Leaves
which fall from the tree should be mowed or removed and composted since the
scab fungus overwinters in fallen leaves.
I am attaching a copy off-list of our spray protocol for you to review for a
non-organic approach to scab that will give you other options. Look at the
recommendation for Scab at green tip, Tight Cluster and Bloom. There is a
list of all of your options with recommendations for rotating sprays between
Captan, EBDCs, SIs and strobilurins. Mancozeb is an EDBC and goes by the
trade name Dithane, which is one of the options we use here at Royal Oak
Farm. You can use Mancozeb up through bloom at the full rate, but after
bloom reduce it to half the rate. Look for pome fruit on the label for the
rate, or use the EcoApple recommended rate of 1 lb/ per 100 gal. It is
possible Mancozeb is not labeled for pome fruit (apples) in Nebraska, but
that would surprise me.
If you have any questions about the recommendations, feel free to contact me
anytime. We are right in the middle of our scab spray program and I use a
disease computer model for timing sprays with the Mill's table. In your
case, with only a few trees, spraying every 5 to 7 days is a good rule to
Hope this helps!
Royal Oak Farm Orchard, Zone 5
----- Original Message -----
From: "William C. Garthright" <billg at inebraska.com>
To: <dmnorton at royaloakfarmorchard.com>; "North American Fruit Explorers"
<nafex at lists.ibiblio.org>
Sent: Wednesday, May 07, 2008 11:08 PM
Subject: Re: [NAFEX] Captan/Sulfur
>> For Captan 80WDG the max per season is 40 lbs. per acre per season no
>> matter what rate you use.
> What would you recommend for Apple Scab, in addition to Captan? I wouldn't
> want to use the same fungicide all season, but I'm having trouble finding
> anything else. I did find some Mancozeb, but it's not rated for apples.
> This is just for me, not a commercial orchard, but I'd imagine there's
> some reason apples aren't on the label, right? I've seen Ferbam
> recommended, too, but I've never seen that anywhere.
> I did use a lime sulfur dormant spray, but I don't want to use Captan
> alone for the rest of the summer (and my Honeycrisp apple was hit really
> hard by scab last year). Any suggestions?
> This isn't my only spray problem. Here in Nebraska, it's hard to find a
> day calm enough to spray. And my fruit trees and plants are crowded pretty
> close together. It's hard to spray one without hitting something else.
> That's particularly a problem when the 'something else' is blooming (at
> least, for some sprays). I didn't think of that when I planted them...
> Lincoln, NE (zone 5)
> The sharpest criticism often goes hand in hand with the deepest idealism
> and love of country. - Robert F. Kennedy
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