1. Does anyone have experimental data, observations, or at least an
interesting theory, for the mechanism by which Indar and Inspire Super
are more effective the first generation DMIs against apple scab?
Our spray guide assigns Indar the same rating as a protectant
(Fair) and same time range for post-infection application (72-96 hours)
as the first generation DMIs. But are there any differences in the
range of forward protection, or in fruit scab prevention vs. foliar scab
prevention between the first generation DMIs and Indar or Inspire Super?
For practical application, the question boils down to:
2. Are the recommendations for application timing, method,
tankmixing, and other considerations for Indar and Inspire Super any
different than for Rally (Nova), Rubigan, and Procure?
... or is it that Indar and Inspire Super should be used in exactly
the same manner as the first generation DMIs (and with proper dose,
tankmix partner, and good coverage of course), with the only difference
being, for now at least, better prospects for getting effective scab
control with the newer materials?
3. In orchards where the first generation DMIs are still effective,
is it preferable to keep using them as long as they work and save Indar
and Inspire Super as a fall back position, or is it better to use the
best DMI available (i.e. Indar or Inspire Super) to present the highest
possible barrier to forestall a shift to DMI resistance in the local
scab population as long as possible?
Thanks for taking the time to ruminate on and reply to any of these
questions.
- Glen
Glen Koehler
University of Maine Cooperative Extension
Pest Management Office
491 College Avenue, Orono, ME 04473
Tel: 207-581-3882
Email: gkoeh...@umext.maine.edu
Web: PRONewEngland.org
Fax: 207-581-3881
What we call the secret of happiness is no more a secret than our
willingness to choose life. - Leo Buscaglia
-----Original Message-----
From: apple-crop@virtualorchard.net
[mailto:apple-c...@virtualorchard.net] On Behalf Of Dave Rosenberger
Sent: Friday, May 01, 2009 10:32 AM
To: Apple-Crop
Subject: Re: Apple-Crop: RE Cedar apple rust
Initial evaluations noted that strobilurin fungicides provided only
"fair" control of apple rust diseases, but that was to some extent an
artifact of the way that the strobilurins were initially tested in
the US. When Flint and Sovran were introduced, we initially thought
that we could use them as substitutes for sterol inhibitor fungicides
(DMI's), and they were therefore tested and used by applying them at
10-day intervals. We now know that the strobies are NOT substitutes
for the DMI fungicides in that they do not have anywhere nearly the
same post-infection and presymptom activity against apple scab. They
are really "super protectant" fungicides, but that means that they
should be applied in schedules with spray intervals similar to those
traditionally used for captan or mancozeb. When I have applied Flint
in this fashion, I have had pretty good control of cedar apple rust
and quince rust in my test plots that are exposed to extremely high
inoculum loads for cedar rust diseases. So the bottom line is that I
think that Flint will work well against rust so long as it is applied
ahead of rust infection periods. I have less experience with Sovran
as a protectant for rust diseases, so I don't know if it would be as
effective against rust as Flint is.
>Hi Con, fair only for rust on the strobilurins -- see:
>
>http://ipmguidelines.org/TreeFruits/content/CH06/default-1.asp
>
>I also wanted to briefly comment on the rest of your post. Of course
>you are 'right,' but obviously we are not likely to change it. Same
>with the discussion about pesticide rate per 100 gallons (based on
>TRV) vs. rate per acre. Of course the former is more accurate and
>makes more sense than the latter, but all the new pesticide labels
>(well, most) are in rate per acre. I think we are just going to have
>to accept the new 'technology,' adapt, and hopefully continue to
>make some money. The current business environment is challenging for
>everyone...
>
>:-)
>
>Jon
>
>
>Jon Clements
>Extension Tree Fruit Specialist
>UMass Cold Spring Orchard
>393 Sabin Street
>Belchertown, MA 01007
>VOICE 413.478.7219
>FAX 413.323.6647
>IM mrhoneycrisp
>Skype Name mrhoneycrisp
>
>
>
>On Apr 30, 2009, at 8:33 AM, Con.Traas wrote:
>
>>PS. Would any of the strobilurins have helped for the cedar rust
>
>
>
>-----------------------------------------------------------------------
---
>
>The 'Apple-Crop' LISTSERV is sponsored by the Virtual
>Orchard<http://www.virtualorchard.net> and managed by Win Cowgill
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>
>Apple-Crop is not moderated. Therefore, the statements do not
>represent"official" opinions and the Virtual Orchard takes no
>responsibility forthe content.
--
**************************************************************
Dave Rosenberger
Professor of Plant Pathology Office: 845-691-7231
Cornell University's Hudson Valley Lab Fax: 845-691-2719
P.O. Box 727, Highland, NY 12528 Cell: 845-594-3060
http://www.nysaes.cornell.edu/pp/faculty/rosenberger/
------------------------------------------------------------------------
--
The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard
<http://www.virtualorchard.net> and managed by Win Cowgill and Jon
Clements <webmas...@virtualorchard.net>.
Apple-Crop is not moderated. Therefore, the statements do not represent
"official" opinions and the Virtual Orchard takes no responsibility for
the content.
--------------------------------------------------------------------------
The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard
<http://www.virtualorchard.net> and managed by Win Cowgill and Jon
Clements <webmas...@virtualorchard.net>.
Apple-Crop is not moderated. Therefore, the statements do not represent
"official" opinions and the Virtual Orchard takes no responsibility for
the content.
