December 2021 - 22

PLANT HEALTH
in my opinion the second best choice for black
root rot (Thielaviopsis), following thiophanate
methyl. Affirm has performed very well on other
diseases from Alternaria leaf spot to Botrytis
blight to Rhizoctonia. At this time, Affirm is
available from NuFarm. You can choose the
best rotational partner once you have a disease
target in mind. There is no standard answer
since the product helps control such a variety of
plant pathogens.
DECREE
The active ingredient of Decree is fenhexamid
and was originally registered in 1999 on some
agricultural crops. Decree is only labeled for
Botrytis on ornamentals, but we did find quite
a lot of activity on some other pathogens when
we first did research trials for SePRO in the late
1990s. Decree has been the most effective at
killing Botrytis spores if disease has started.
The first year we did research on the numbered
compound, almost all of the researchers across
the U.S. reported on its unique ability to wipeout
spores. It has been an industry standard for
Botrytis control since it was first registered. We
also have seen very safe use on many crops that
are flowering.
At one point, Botrytis resistance to Decree
was reported (Moorman, Penn State University)
in a limited way so overuse should be avoided.
As always choose another very effective
product for Botrytis - not one that gives only
" some " control. These include 7/11 fungicides
(especially Broadform and Orkestra Intrinsic),
Palladium (or Medallion or Emblem), iprodione
(like Chipco 26019), and chlorothalonil (Daconil).
Additionally, make use of the highest label rate
for Decree (24 oz/10 gal) if a severe outbreak
FRAC No. Some choices for an effective rotation
Adorn
Affirm
Decree
Pipron
Segovis
Segway O
Seido
43
19
17
5
49
21
50
Mix with Subdue Maxx (4), then alternate with Segovis or Segway, FRAC 40
or 40/45, any phosphonate (PO5-previously called 33)
Tmethyl (1) for BRR or Rhizoctonia, many choices for Botrytis including
Decree
Any 7/11 (especially Broadform and Orkestra Intrinsic),
Any FRAC 3 (like Avelyo or Eagle) or Seido, also any FRAC 7/11
FRAC 40 or 40/45, any phosphonate (PO5-previously called 33)
For Pythium - FRAC 14 (Terrazole) or Subdue Maxx (FRAC 4), for downy
mildew or Phytophthora - FRAC 40 or 40/45, any phosphonate (PO5previously
called 33)
Any FRAC 3 (like Avelyo or Eagle) or Pipron, any FRAC 7/11 (especially
Broadform)
Table 2. Possible rotational choices for seven fungicides (only members of unique FRAC groups).
occurs before you can get a preventative
fungicide on the crop and you need to stop
spore production fast.
PIPRON
Piperalin was originally registered in the U.S.
in 1964 on agricultural crops. I could not find
the first registration on ornamentals, but it
has been available from SePRO since the late
1990s. Pipron was one of the few powdery
mildew products that was believed (and proven)
to be an excellent eradicant. Somehow this led
to the idea it was not a good preventative. So
since I always like a challenge, we tested it in
California and it really is very good as either a
preventative or an eradicant.
L&GR provides
information
for retailers on:
LAWN & GARDEN RETAILER
SUBSCRIBE TO
FOR FREE!
Marketing
Merchandising
Management
Products
Inspiration
SEGOVIS
This Phytophthora and downy mildew
PRINT AND DIGITAL
OPTIONS AVAILABLE
LGRMAG.COM/SUBSCRIBE
Subscribe now at
LGRMAG.COM/DIGITAL
Preview the digital edition at
fungicide is extremely long-term in its efficacy.
Trials in Florida on Impatiens downy mildew
showed a single drench to last up to 80 days. It
was originally registered by Syngenta in 2015
and can be applied as a spray or drench, with
drenches sometimes lasting longer than a foliar
spray. You have many excellent choices for
other FRAC group products for downy mildew
or Phytophthora (Table 2). Consider using
Segovis as a first treatment for the longestlasting
effects, then follow up with a different
fungicide. The low use rates and long-lasting
effects make this unique fungicide a critical
part of a rotation. Consider tank-mixing with
another fungicide like Subdue Maxx or Adorn
to make sure resistance doesn't develop;
this is not required by the label, but is my
own suggestion.
SEGWAY O
We started working with ISK Biotech around
1998 on many Oomycetes organisms (downy
mildew, Phytophthora and Pythium). The active
ingredient is cyazofamid, and it was registered
on ornamentals around 2003. We saw very safe,
high efficacy on all three types of Oomycetes
organisms. Segway O is available from OHP.
See Table 2 for some suggestions of effective
rotational partners.
SEIDO
The newest FRAC group is 50 and contains
only pyriofenone (active ingredient in Seido)
from OHP. Seido was registered in 2021. We've
performed trials over the past few years both
in Arizona and in the field in California. Seido
only works on powdery mildew and, based on
trials, should be used at 5 oz/100 gal. It has
low residue and could be alternated with many
different powdery mildew fungicides (Table 2).
CONCLUSION
It will be interesting to see what comes next
whether it is another new FRAC group or another
new pre-mix. Stay tuned for updates!
A.R. Chase is plant pathologist at Chase Agricultural
Consulting LLC and can be reached at archase@
chaseresearch.net.
Remembering or checking which fungicides are in what FRAC groups can be a challenge. Ann and Mike
have developed a new 13x19 inch wall poster/pictorial guide to the FRAC groups. Contact one of them to
order your copy. archase@chaseresearch.net or mike@chaseresearch.net.
22 DECEMBER 2021 GPNMAG.COM

http://www.LGRMAG.COM/SUBSCRIBE http://www.LGRMAG.COM/DIGITAL http://www.GPNMAG.COM

December 2021

Table of Contents for the Digital Edition of December 2021