December 2021 - 20

PLANT HEALTH
One of a Kind:
FRAC Groups
with a Single Fungicide
How can you successfully incorporate these seven fungicides into your rotation?
BY A.R. CHASE
T
he advent of the age of pre-mixes and
re-worked mixes has been with us for
the past 10 years and will no doubt
continue. If you have been in the green industry
as long as I have, you will remember Banrot
(FRAC 1, 14), one of our first pre-mixes for
ornamentals - and indeed you may still be using
it. Our newest pre-mix is Postiva (FRAC 3, 7)
which was just registered by Syngenta.
On the other end of the spectrum, we have
some fungicide products that are not only a
single active ingredient but they are the only
representative of a single FRAC (fungicide
resistance action committee) group. Some
of these products were first registered over
30 years ago like Pipron (powdery mildew
Fungicide REI
Adorn
Affirm
Decree
Pipron
Segovis
Segway O
Seido
12 hr
4 hr
12 hr
12 hr
4 hr
12 hr
4 hr
FRAC
No.
43
19
Company
NuFarm
NuFarm
fungicide from SePRO), while others have
recently been registered like Seido (powdery
mildew fungicide from OHP).
In this article, I decided to review the single
fungicides in seven unique FRAC groups with
an eye toward their history, efficacy range
and best ways to employ them in an effective
fungicide rotation.
One of the biggest benefits to using one of
these fungicides is that you can rotate with
virtually anything (that actually works on
the target) and avoid issues with resistance
development due to overuse of a FRAC group.
Additionally, simply adding a unique FRAC
group to a rotation is a large benefit in keeping
resistance at bay even if you have mainly
Target pathogen(s)
Phytophthora, downy mildew
Botrytis, Rhizoctonia, Thielaviopsis,
powdery mildew, Alternaria, others
17 SePRO Corp. Botrytis
5
49
(U15)
21
50
SePRO Corp. Powdery mildew
Syngenta
OHP Inc.
OHP Inc.
Phytophthora, downy mildew
Phytophthora, downy mildew,
Pythium
Powdery mildew
Table 1. Seven fungicides that are sole members of a unique FRAC groups.
20 DECEMBER 2021 GPNMAG.COM
Kills spores
Safe on flowers
Preventative
and curative
Long-lasting,
effective as spray
or drench
Special features
been rotating premixes or other very effective
products. Table 1 summarizes features of
the seven fungicides that fall into this unique
category.
ADORN
Adorn was originally registered by Valent in
2009 and is currently available from NuFarm.
Adorn consists of fluopicolide, the only member
of FRAC 43 available on ornamentals. The
product works primarily on Phytophthora and
downy mildew oomycetes and on certain species
of Pythium. Due to concerns on resistance
management and retaining maximum benefits,
the label requires that it be mixed with another
fungicide that is effective on Phytophthora or
downy mildew. Additionally, it was not registered
for Pythium although some trials showed high
efficacy. Since we are not always aware of the
species of Pythium we are trying to prevent this
seems like a good strategy to avoid failures.
There are a large number of other products
that are very effective on downy mildew and
Phytophthora, including: phosphonates (like
Aliette), Subdue Maxx, Segway O, FenStop, and
products with FRAC 40 (Micora, Orvego and
Stature). Although you should be sure to check
compatibility of Adorn with the chosen mixing
partner before use, I have never heard of an
incompatibility issue.
AFFIRM
Affirm is polyoxin D zinc salt and we started
working on it while it was still a numbered
compound. Originally there was another
product with the same active ingredient
(Endorse), but it was registered by Cleary in
2009. Affirm is very broad-spectrum and can
be used for foliar and soil-borne diseases. It is
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December 2021

Table of Contents for the Digital Edition of December 2021
