3. growertalks 2014-2015 Insecticide & Fungicide Guide 3
editorial
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Welcome!
Insects. Diseases. No matter how sophisticated we in horticul-
ture get, we’ll never completely eliminate those two banes of our
existence.
Thankfully, there are smart scientists in the pest management
industry, such as our sponsor, Syngenta Plant Protection, working
24/7 to develop new products—both chemical and biological—that
are more effective, more targeted, safer and easier to use than ever be-
fore. Additionally, there are researchers in academia and the private sector who
dedicate their careers to finding methods for maximizing all the tools at our
disposal to control those aforementioned pests.
Hence, the purpose of GrowerTalks’ biannual Insect & Fungicide Guide: to
bring you the most current listings of available pest management products and the
newest methods for using them.
For instance, on page 4, Dr. Steve Frank of North Carolina State University
shares up-to-date details on thrips control, including tips for breaking the thrips
population cycle, which he thinks “accounts for 90% of calls to Extension and
industry personnel.”
Turning to the disease portion of this guide on page 12, Plant Pathologist Ann
Chase of Chase Horticultural Research lays out the differences between using
pre-mixed fungicides versus tank-mixing your own combinations (hint: there’s no
wrong answer).
On page 16, Nancy Rechcigl, a Technical Service Representative with Syngenta,
offers best practices for sound disease management. She quotes Ben Franklin’s
famous line, “An ounce of prevention is worth a pound of cure,” which could have
been written specifically about greenhouse disease management.
And since everyone involved in this guide is invested in offering broad-based
alternatives for your insect and disease management program, on page 20, Suzanne
Wainwright-Evans (the Buglady) outlines the basics of biological control in
production—including when and how to use pesticide sprays.
Finally, all of the above will be much more effective if utilized within the frame-
work of a proper ICM—integrated crop management—program. On page 23,
Marla Faver covers the eight elements of a successful ICM program, including the
most important one: scouting, which she says is “the only way for a grower to have
an intimate knowledge of his crop and potential disease and pest pressures.”
Of course, it’s the charts that make this a handy year-round reference: the
Insecticide Guide begins on page 5, the chemical class chart on page 14 and the
Fungicide Guide on page 17.
A special thanks to our sponsor, Syngenta (whose products are in bold in the
charts), and to all of our contributors.
Good growing,
Chris Beytes, Editor
GrowerTalks/Green Profit
Disclaimer: These recommendations may not be appropriate for conditions in all states and may not comply with laws and regulations in
every state. These recommendations were current as of September 2014. Individuals who use agricultural chemicals are responsible for
ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information
about usage regulations and examine a current product label before purchasing or applying any chemical. For assistance, contact your county
Cooperative Extension Agent or pest control advisor. The use of brand names and any mention or listing of commercial products or services
in this publication does not imply endorsement by Ball Publishing.
4. 4 growertalks 2014-2015 Insecticide & Fungicide Guide
If greenhouse growers have a worst pest,
it’s Western flower thrips. They’ve been
called “the most damaging greenhouse
pest in the world” for good reason. They
reproduce quickly, feed on most crops and
evade insecticides in at least three different
ways. Western flower thrips damage most
bedding plants, cut flowers, foliage plants
and perennials, and can cause double
damage to ornamental plants by feeding
on leaves and flowers. They scrape plant
tissue then suck the juices that are released.
This causes abraded patches of tissue
on leaves that eventually become silvery
or brown. On flowers, the damage may
appear as white or brown streaks on petals.
Thrips also leave small black fecal pellets at
feeding sites. When thrips feed on young
leaves or buds, the leaves become distorted
as they grow.
In this article, we’ll explore the
ways to circumvent thrips’ trickery and
optimize insecticide efficacy. We’ll also
clear up some common misconceptions
about why insecticides sometimes
appear to fail. Understanding some basic
biology combined with monitoring and
application techniques, you can improve
thrips management and crop protection.
Biology
Western flower thrips feed on hundreds
of plant species. This means almost any
flower, vegetable or herb you grow is
susceptible to thrips feeding and damage.
It also means that any weeds growing in or
around your greenhouse can also support
thrips. This adaptive biology has helped
Western flower thrips spread around the
world. It can certainly help them set up
shop in your greenhouse and stay there.
This affects insecticide efficacy because
thrips can easily move from sprayed to
unsprayed plants. If you spot-treat one
section of a house, thrips will just move
to the next crop down. If you spray
the benches but have weeds growing in
corners or below the benches, thrips will
just flit over to the weeds. Thus, if thrips
are present, it’s generally best to treat the
entire greenhouse or compartment rather
than just the most infested crops. Needless
to say, if you have weeds, get rid of
them. Weeds can also harbor many other
arthropod pests and diseases.
Western flower thrips’ life cycle also
helps them evade insecticides. They lay
eggs in leaf tissue. Larvae hatch a couple
days later and feed on leaves and flowers
for about a week. Thrips pupate in the soil
then emerge as adults that can fly from
plant to plant laying eggs and feeding
for weeks. Eggs embedded in leaves
aren’t killed by insecticide applications.
Neither are pupae; they’re snug in the soil.
This leaves just half of thrips’ life stages,
larvae and adults that are susceptible to
insecticide applications. Thus, even if you
had a magical insecticide that killed every
thrips adult and larvae (you don’t, by the
way), the next day, new larvae will hatch
from eggs and new adults will emerge from
pupae in the soil.
Breaking the cycle
I believe this aspect of thrips biology
accounts for 90% of calls to Extension
and industry personnel that go something
like, “I sprayed X insecticide last week and
it didn’t work” or “I have resistant thrips
because I sprayed X insecticide and still
have thrips.” In some cases, insecticides
don’t work (wrong product, old product,
low or high pH, poor mixing) and, yes,
thrips can develop insecticide resistance. In
most cases though, especially when trying
to subdue an outbreak, one application
is just not enough. To break the thrips
population cycle, you need two to three
applications five to seven days apart. This
will hopefully kill larvae that hatch after
the first application before they reproduce
and kill adults that emerge from pupae
before they lay too many eggs. By the third
application, the goal would be to have
very few new eggs present and even fewer
adults.
The efficacy of this plan depends
on killing as many of the susceptible
larvae and adults as possible with each
application. Another way thrips evade
insecticides is just by hiding. Thrips feed
in concealed places. The most accessible
place thrips feed is the underside of leaves.
Less accessible places include in flowers
and between layers of petals, in buds
and under unexpanded leaves, and all
the other nooks and crannies of plants.
These concealed feeding sites are hard to
cover with insecticides. To make matters
worse, leaves that expand the day after
you apply a contact insecticide doesn’t
have insecticide residue. Flowers are the
same way. Thrips love flowers and flowers
that open after an application don’t have
residue. In addition, systemic insecticides
aren’t transported well to flower petals,
which are favored feeding sites and critical
to plants’ aesthetic value. Part of the lesson
here is that you cannot rely on insecticides
to protect plants from thrips feeding when
thrips abundance is high. The goal should
be to keep thrips abundance low enough
that very little feeding occurs in the first
place.
Another misconception is that there
aren’t many insecticides available for
thrips. In fact, there are many good
insecticides, but you need to give them a
fighting chance. For the reasons outlined,
even the best insecticides will only kill
some percentage of the thrips in your
greenhouse. Therefore, it’s better to stay
ahead and keep thrips abundance low
rather than try to catch-up. To stay ahead,
How Thrips Evade Insecticides
By Steve Frank
Photo:A.Ernst,NCSU.
Western flower thrips larva.
5. growertalks 2014-2015 Insecticide & Fungicide Guide 5(Pest Control Material in bold typeface are from Syngenta.)
it’s important to monitor thrips abundance
with sticky cards. This will alert you to gradual
population changes as thrips reproduce within
your house and will also alert you to sudden
changes due to external factors.
For example, if your neighbor mows his
hay field, you could get a sudden influx of
homeless thrips that would require immediate
action. You wouldn’t know this until several
days—and much feeding and egg laying—had
passed without sticky cards. Yellow sticky cards
hung just above the crop canopy will catch
adult thrips. Records of when and where you
catch thrips throughout the year may help you
identify seasonal or spatial patterns that help
you predict thrips abundance and improve
management. In most cases, even a few thrips
caught on sticky cards is cause for action.
Thrips have a lot of tricks that help them
evade insecticide applications. We can’t change
thrips biology, but we can improve control by
monitoring, targeting small populations and
making multiple applications when necessary to
interrupt their population cycle. Knowing your
enemy will help you knock them down. GT
Insect
or Mite Pest
Pest Control Material
Common Name
Pest Control Material
Trade Name(s)
Restricted Entry
Interval (REI)
Mode of Action
(IRAC Mode of Action Classification)
APHID
q
Methiocarb Mesurol 24 hours Acetylcholine Esterase Inhibitor (1A)
Chlorpyrifos DuraGuard 24 hours Acetylcholine Esterase Inhibitor (1B)
Malathion Gown Malathion 8F 12 hours Acetylcholine Esterase Inhibitor (1B)
Acephate Orthene 24 hours Acetylcholine Esterase Inhibitor (1B)
Bifenthrin Attain/Talstar 12 hours Sodium Channel Blocker (3)
Cyfluthrin Decathlon 12 hours Sodium Channel Blocker (3)
Fluvalinate Mavrik 12 hours Sodium Channel Blocker (3)
Lambda-cyhalothrin Scimitar GS 24 hours Sodium Channel Blocker (3)
Fenpropathrin Tame 24 hours Sodium Channel Blocker (3)
Pyrethrins N/A 12 hours Sodium Channel Blocker (3)
Thiamethoxam Flagship 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Imidacloprid Marathon 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Dinotefuran Safari 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Acetamiprid TriStar 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Abamectin Avid 12 hours GABA Chloride Channel Activator (6)
Kinoprene Enstar II 4 hours Juvenile Hormone Mimic (7A)
Fenoxycarb Preclude 12 hours Juvenile Hormone Mimic (7B)
Pymetrozine Endeavor 12 hours Selective Feeding Blocker (9B)
Flonicamid Aria 12 hours Selective Feeding Blocker (9C)
Azadirachtin Azatin, Molt X, Azatrol/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Steve Frank is Associate Professor and Extension Specialist in the Entomology Department
at North Carolina State University. You can reach him at sdfrank@ncsu.edu or visit his website
http://ecoipm.com.
Fresh feeding and feces from thrips feeding on ornamental pepper leaves.
Photo:S.D.Frank,NCSU.
9. growertalks 2014-2015 Insecticide & Fungicide Guide 9(Pest Control Material in bold typeface are from Syngenta.)
Insect
or Mite Pest
Pest Control Material
Common Name
Pest Control Material
Trade Name(s)
Restricted Entry
Interval (REI)
Mode of Action
(IRAC Mode of Action Classification)
PLANT BUG/
LYGUS BUG
continued
Fenpropathrin Tame 24 hours Sodium Channel Blocker (3)
Thiamethoxam Flagship 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Dinotefuran Safari 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Acetamiprid TriStar 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Buprofezin Talus 12 hours Chitin Synthesis Inhibitor (16)
Azadirachtin Azatin, Molt X, Azatrol/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Potassium Salts of Fatty Acids Insecticidal Soap 12 hours Desiccation or Membrane Disruptor
Petroleum Oil PureSpray Green/SufOil X/Saf-T-Side 4 hours Suffocation or Membrane Disruptor
Paraffinic Oil Ultra-Fine Oil 4 hours Suffocation or Membrane Disruptor
Beauveria bassiana BotaniGard/Naturalis 4 hours Unclassified by IRAC
Isaria fumosorosea Apopka Strain 97 Preferal 4 hours Unclassified by IRAC
SCALES
(HARD AND
SOFT)
Acephate Orthene/Precise 24/12 hours Acetylcholine Esterase Inhibitor (1B)
Bifenthrin Attain/Talstar 12 hours Sodium Channel Blocker (3)
Cyfluthrin Decathlon 12 hours Sodium Channel Blocker (3)
Fluvalinate Mavrik 12 hours Sodium Channel Blocker (3)
Imidacloprid Marathon/Benefit/Mantra 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Dinotefuran Safari 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Acetamiprid TriStar 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Kinoprene Enstar II 4 hours Juvenile Hormone Mimic (7A)
Fenoxycarb Preclude 12 hours Juvenile Hormone Mimic (7B)
Pyriproxyfen Distance 12 hours Juvenile Hormone Mimic (7C)
Buprofezin Talus 12 hours Chitin Synthesis Inhibitor (16)
Azadirachtin Azatin/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Petroleum Oil PureSpray Green 4 hours Suffocation or Membrane Disruptor
Clarified Hydrophobic Extract of
Neem Oil
Triact 4 hours Suffocation or Membrane Disruptor
Paraffinic Oil Ultra-Fine Oil 4 hours Suffocation or Membrane Disruptor
SHORE FLY Chlorpyrifos DuraGuard 24 hours Acetylcholine Esterase Inhibitor (1B)
Thiamethoxam Flagship 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Pyriproxyfen Distance 12 hours Juvenile Hormone Mimic (7C)
Diflubenzuron Adept 12 hours Chitin Synthesis Inhibitor (15)
Cyromazine Citation 12 hours Chitin Synthesis Inhibitor (17)
Azadirachtin Azatin/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Potassium Salts of Fatty Acids Insecticidal Soap 12 hours Desiccation or Membrane Disruptor
SLUG AND
SNAIL
Methiocarb Mesurol 24 hours Acetylcholine Esterase Inhibitor (1A)
Metaldehyde Deadline/Metarex 24 hours Unclassified by IRAC
Iron Phosphate Sluggo 0 hours Unclassified by IRAC
TWOSPOTTED
SPIDER MITE
q
Abamectin Avid 12 hours GABA Chloride Channel Activator (6)
Emamectin benzoate Enfold 12 hours GABA Chloride Channel Activator (6)
Hexythiazox Hexygon 12 hours Growth and Embryogenesis Inhibitor (10A)
10. 10 growertalks 2014-2015 Insecticide & Fungicide Guide
Insect
or Mite Pest
Pest Control Material
Common Name
Pest Control Material
Trade Name(s)
Restricted Entry
Interval (REI)
Mode of Action
(IRAC Mode of Action Classification)
TWOSPOTTED
SPIDER MITE
continued
Clofentezine Ovation 12 hours Growth and Embryogenesis Inhibitor (10A)
Etoxazole TetraSan 12 hours Chitin Synthesis Inhibitor (10B)
Fenbutatin-oxide (Hexakis) ProMite 48 hours Oxidative Phosphorylation Inhibitor (12B)
Chlorfenapyr Pylon 12 hours Oxidative Phosphorylation Uncoupler (13)
Acequinocyl Shuttle O 12 hours Mitochondria Electron Transport Inhibitor (20B)
Fenpyroximate Akari 12 hours Mitochondria Electron Transport Inhibitor (21)
Fenazaquin Magus 12 hours Mitochondria Electron Transport Inhibitor (21)
Pyridaben Sanmite 12 hours Mitochondria Electron Transport Inhibitor (21)
Spiromesifen Judo 12 hours Lipid Biosynthesis Inhibitor (23)
Spirotetramat Kontos 24 hours Lipid Biosynthesis Inhibitor (23)
Bifenazate Floramite 4 hours GABA-Gated Antagonist (25)
Bifenazate+abamectin Sirocco 12 hours
GABA-Gated Antagonist (25) GABA Chloride Channel
Activator (6)
Cyflumetofen Sultan 12 hours Mitochrondrial complex II electron transport inhibitor (25)
Potassium Salts of Fatty Acids Insecticidal Soap 12 hours Desiccation or Membrane Disruptor
Petroleum Oil PureSpray Green/SufOil X/Saf-T-Side 4 hours Suffocation or Membrane Disruptor
Clarified Hydrophobic Extract of
Neem Oil
Triact 4 hours Suffocation or Membrane Disruptor
Paraffinic Oil Ultra-Fine Oil 4 hours Suffocation or Membrane Disruptor
Isaria fumosorosea Apopka Strain 97 Preferal 4 hours Unclassified by IRAC
THRIPS
u
Methiocarb Mesurol 24 hours Acetylcholine Esterase Inhibitor (1A)
Chlorpyrifos DuraGuard 24 hours Acetylcholine Esterase Inhibitor (1B)
Acephate Orthene/Precise 24/12 hours Acetylcholine Esterase Inhibitor (1B)
Bifenthrin Attain/Talstar 12 hours Sodium Channel Blocker (3)
Cyfluthrin Decathlon 12 hours Sodium Channel Blocker (3)
Fluvalinate Mavrik 12 hours Sodium Channel Blocker (3)
Lambda-cyhalothrin Scimitar GS 24 hours Sodium Channel Blocker (3)
Thiamethoxam Flagship 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Imidacloprid Marathon 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Dinotefuran Safari 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Pyridalyl Overture 12 hours Unclassified by IRAC
Acetamiprid TriStar 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Spinosad Conserve 4 hours
Nicotinic Acetylcholine Receptor Agonist and GABA Chloride
Channel Activator (5)
Abamectin Avid 12 hours GABA Chloride Channel Activator (6)
Kinoprene Enstar II 4 hours Juvenile Hormone Mimic (7A)
Fenoxycarb Preclude 12 hours Juvenile Hormone Mimic (7B)
Flonicamid Aria 12 hours Selective Feeding Blocker (9C)
Chlorfenapyr Pylon 12 hours Oxidative Phosphorylation Uncoupler (13)
Azadirachtin Azatin, Molt X/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Tolfenpyrad Hachi-Hachi 12 hours Mitochondria Electron Transport Inhibitor (21)
11. growertalks 2014-2015 Insecticide & Fungicide Guide 11(Pest Control Material in bold typeface are from Syngenta.)
Insect
or Mite Pest
Pest Control Material
Common Name
Pest Control Material
Trade Name(s)
Restricted Entry
Interval (REI)
Mode of Action
(IRAC Mode of Action Classification)
THRIPS
continued
Cyantraniliprole Mainspring 4 hours Ryanodine Receptor Modulator (28)
Petroleum Oil PureSpray Green/SufOil X/Saf-T-Side 4 hours Suffocation or Membrane Disruptor
Paraffinic Oil Ultra-Fine Oil 4 hours Suffocation or Membrane Disruptor
Beauveria bassiana Botanigard 4 hours Unclassified by IRAC
Isaria fumosorosea Apopka Strain 97 Preferal 4 hours Unclassified by IRAC
Pyridalyl Overture 12 hours Unclassified by IRAC
WHITEFLY Acephate Orthene/Precise 24/12 hours Acetylcholine Esterase Inhibitor (1B)
Bifenthrin Attain/Talstar 12 hours Sodium Channel Blocker (3)
Cyfluthrin Decathlon 12 hours Sodium Channel Blocker (3)
Fluvalinate Mavrik 12 hours Sodium Channel Blocker (3)
Fenpropathrin Tame 24 hours Sodium Channel Blocker (3)
Pyrethrins N/A 12 hours Sodium Channel Blocker (3)
Thiamethoxam Flagship 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Imidacloprid Marathon 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Dinotefuran Safari 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Acetamiprid TriStar 12 hours Nicotinic Acetylcholine Receptor Disruptor (4A)
Spinosad Conserve 4 hours
Nicotinic Acetylcholine Receptor Agonist and GABA Chloride
Channel Activator (5)
Abamectin Avid 12 hours GABA Chloride Channel Activator (6)
Kinoprene Enstar II 4 hours Juvenile Hormone Mimic (7A)
Fenoxycarb Preclude 12 hours Juvenile Hormone Mimic (7B)
Pyriproxyfen Distance 12 hours Juvenile Hormone Mimic (7C)
Pymetrozine Endeavor 12 hours Selective Feeding Blocker (9B)
Flonicamid Aria 12 hours Selective Feeding Blocker (9C)
Diflubenzuron Adept 12 hours Chitin Synthesis Inhibitor (15)
Novaluron Pedestal 12 hours Chitin Synthesis Inhibitor (15)
Buprofezin Talus 12 hours Chitin Synthesis Inhibitor (16)
Azadirachtin Azatin/Ornazin 4/12 hours Ecdysone Antagonist (18B)
Pyridaben Sanmite 12 hours Mitochondria Electron Transport Inhibitor (21)
Spiromesifen Judo 12 hours Lipid Biosynthesis Inhibitor (23)
Spirotetramat Kontos 24 hours Lipid Biosynthesis Inhibitor (23)
Cyantraniliprole Mainspring 4 hours Ryanodine Receptor Modulator (28)
Potassium Salts of Fatty Acids Insecticidal Soap 12 hours Desiccation or Membrane Disruptor
Petroleum Oil PureSpray Green 4 hours Suffocation or Membrane Disruptor
Clarified Hydrophobic Extract of
Neem Oil
Triact 4 hours Suffocation or Membrane Disruptor
Paraffinic Oil Ultra-Fine Oil 4 hours Suffocation or Membrane Disruptor
Beauveria bassiana Botanigard/Naturalis/Mycotrol 4 hours Unclassified by IRAC
Isaria fumosorosea Apopka Strain 97 Preferal 4 hours Unclassified by IRAC
12. 12 growertalks 2014-2015 Insecticide & Fungicide Guide (Pest Control Material in bold typeface are from Syngenta.)
Combining products for an application
has been and will be common in
ornamental production. It can be a
mixture of diverse products from fertilizer
and minor elements to adjuvants to
insecticides, miticides, fungicides and
bactericides. For disease prevention and
control, the choice of using premixes
versus creating your own through tank
mixing is a critical decision.
Pre-mixes
Use of pre-mix fungicides can be driven
by a variety of goals, including resistance
management, ease of use, cost effectiveness
and breadth of activity. Using a pre-mix
will give you the security of knowing
that the two products are chemically
suited to work together and, in some
cases, both are effective on the target
disease. The following table shows some
of the premixes available to ornamental
producers. I’ve included the FRAC groups
to demonstrate why some pre-mixes are
additive and others aide in resistance
management.
Pre-mixes have both positive and
negative aspects. Some of the positive
aspects include: 1) diagnosis is less critical;
2) mixed infections are covered; 3) plant
safety is known; 4) resistance management;
5) improved efficacy; 6) fewer products on
the shelf; and 7) can be more cost effective.
If you don’t have time for a lab diagnosis
of a problem, use of a pre-mix that covers
the most common disease possibilities
would allow more timely control. It’s
always better to obtain a diagnosis since
not all problems are due to bacteria or
fungi. Viruses, phytotoxicity, nutritional
imbalance and temperature extremes
won’t be cured by a fungicide whether it’s
a pre-mix or not. In the same vein, there
are often mixed infections of two or more
fungi causing a disease. This is especially
common in root diseases, but sometimes
leaf damage is caused by more than one
fungus or bacterium. If you apply a pre-
mix with the right combination of active
ingredients, you’ll control both problems
with a single application.
Since application of more than one
fungicide at a time is common, using
a pre-mix will give you the security
of knowing that the two products are
chemically suited to work together.
Making your own mixtures has the
drawback of possible phytotoxicity and
only your experience can determine safety
of the mixture under your conditions.
One of the most important aspects of
pre-mixes is that if the correct partners
are chosen, they’re excellent for resistance
management. The only requirement is
that both active ingredients target the
pathogen. For instance, both copper
and mancozeb in the pre-mix Junction
work on bacteria like Pseudomonas and
Xanthomonas. Botrytis resistance can
be delayed with Palladium since both
cyprodinil and fludioxonil target Botrytis.
Finally, stocking pre-mixes is an
attractive solution to the confusion that
can occur by having every fungicide and
bactericide that’s labeled on ornamentals.
It will, obviously, also be much more
cost effective, especially for the smaller
producer who might not use large
quantities of these products.
Table 1. Some premix fungicides for ornamentals.
Fungicide Manufacturer Components (FRAC group) Nature of pre-mix Key targets
Banrot 40WP Scotts Company Thiophanate methyl (1)/ etridiazole (14) additive soil-borne pathogens
Concert II Syngenta Chlorothalonil (M5)/propiconazole (3) additive/resistance management foliar diseases
(except downy mildew)
Hurricane WDG Syngenta Fludioxonil (12)/mefenoxam (4) additive soil-borne pathogens
Junction SePRO Copper hydroxide (M1)/mancozeb (M3) resistance management foliar diseases
Orvego BASF Corp. Dimethomorph (40)/ ametoctradin (45) resistance management downy mildew, Phytophthora
Pageant BASF Corp. Pyraclostrobin (11)/ boscalid (7) additive/resistance management foliar and crown diseases
Palladium Syngenta Fludioxonil (12) /cyprodinil (4) additive/resistance management foliar diseases
(except downy mildew)
RootShield Plus BioWorks Trichoderma harzianum T-22/T. virens G41 additive soil-borne pathogens
Spectro 90WDG Cleary Chemical Company Chlorothalonil (M5)/ thiophanate methyl (1) additive/resistance management foliar diseases
Strike Plus OHP Trifloxystrobin (11)/ triadimefon (3) additive/resistance management foliar and crown diseases
Pre-mix Fungicides vs. Tank Mixing
By A. R. Chase
13. growertalks 2014-2015 Insecticide & Fungicide Guide 13
Some possible negative aspects of pre-mixes
are that the specific ratios of the two active
ingredients may not be ideal for all diseases and
that using a pre-mix may give you a false sense
of security. They think they’ve covered all of the
possible bases and, unfortunately, there’s always
a new disease that escapes the broad-spectrum
treatment. These growers usually wait until
it’s too late to notice that something is amiss
and then the crop is ready for the dumpster.
Pre-mixes aren’t insurance policies—they’re
conveniences.
Tank mixes
Tank mixing can be a better solution in a
number of situations. It gives the user ultimate
control of the rates and specific products
utilized. Certainly, there’s not a pre-mix for all
situations and thus you may need to do your
own customized tank-mix.
Sometimes, tank mixing is mandated by
the product label. This is the case with Adorn,
which must be tank-mixed with another
fungicide from a different FRAC group for any
use. Subdue Maxx must be tank-mixed (also
with a fungicide from another FRAC group)
if it’s used as a foliar spray for downy mildew.
These restrictions are specifically designed for
resistance management (delaying resistance
development).
One of the biggest drawbacks of tank
mixing is the practice of decreasing the rates
of the two (or more) products mixed. It’s not
recommended in any case to reduce rates even
when they’re combined. This is actually exactly
what a scientist would do to create resistance
in a population of a pathogen to that particular
active ingredient or FRAC group.
Conclusions
Pre-mixes save time and allow the user to be
less involved in your disease management. Tank
mixes are by nature customized and allow you to
be more involved in your disease management.
In the case of pre-mixes, you’re making use of
outside expertise and, in the case of tank mixing,
you’re becoming the expert. Both are valid and
effective ways to approach disease management
in ornamental production. GT
Ann Chase is a plant pathologist and president of Chase Horticultural Research, Inc.,
Mt. Aukum, California; www.chasehorticulturalresearch.com.
A poinsettia starting with bad roots.
A mixed infection of Alternaria and Xanthomonas leaf spots on zinnia.
14. 14 growertalks 2014-2015 Insecticide & Fungicide Guide
Chemical Class Chart for Ornamental Fungicides
FRAC group Chemical Class Active Ingredient common name Trade Name
1 Methyl Benzimidazole Carbamates (Thiophantes) thiophanate-methyl AllBan Flo, Banrot*, 3336, ConSyst*, OHP 6672, Spectro*, SysTec 1998,
T-Storm, TM 4.5, TM/C*, 26/36*, Zyban*
2 Dicarboximides iprodione Chipco 26019, Lesco 18 Plus, OHP 26GT-O, 26/36*
3 Demethylation Inhibitors (imidazole, pyrimidine,
triazole)
fenarimol Rubigan
imazalil Fungaflor TR
metconazole Tourney (not registered for use in CA)
myclobutanil Clevis*, Eagle, MANhandle*, Systhane
propiconazole Banner Maxx, Concert II*
triadimefon Strike 50
triflumizole Terraguard
triticonazole Trinity
4 Phenylamides mefenoxam Hurricane WDG*, Subdue GR, Subdue Maxx
5 Amines “Morpholines” (Piperadines) piperalin Pipron
7 Succinate dehydrogenase inhibitors - SDHI
(Pyridine carboxamides, phenyl-benzamides)
boscalid Pageant*
flutolanil Contrast, Prostar
9 Anilinopyrimidines cyprodinil Palladium*
11 QoI-fungicides (strobilurins) azoxystrobin Heritage
fluoxastrobin Disarm O
kresoxim-methyl Cygnus
pyraclostrobin Insignia, Pageant*, Empress
trifloxystrobin Compass O
Imidazolinone fenamidone Fenstop
12 Phenylpyrroles fludioxonil Hurricane WDG*, Medallion WDG, Palladium*, Mozart™ TR
14 Aromatic Hydrocarbons (chlorophenyl) dicloran Botran
pentochloronitrobenzene (PCNB) Terraclor
Thiadiazole etridiazole Banrot*, Terrazole, Terrazole CA, Truban
17 Hydroxyanalide fenhexamide Decree
19 Polyoxins polyoxin - D Endorse, Affirm WDG, Veranda O
21 Quinone inside inhibitors (Cyano-imidazole) cyazofamid Segway O
28 Carbamate propamocarb Banol
33 Phosphonates fosetyl-Al Aliette
phosphorous acid, potassium phosphite Alude, Biophos, Fosphite, Reliant, Vital
40 Carboxylic Acid Amines
(cinnamic acid amides, mandelic acid amides)
dimethomorph Stature DM, Orvego*
mandipropamid Micora
43 Benzamides (Pyridinemethyl-benzamides) fluopicolide Adorn
44 Microbials Bacillus subtilis (QST 713) Cease, Companion
Bacillus subtilis (MBI600) Subtilex NG
45 Quinone x Inhibitor ametoctradin Orvego*
M1 (multi-site) Inorganics copper salts Camelot O, Champion, Copper-Count N, CuPro 5000, Cuproxat, Junction*,
Nordox, Nu-Cop, Phyton 27, Phyton 35
M3 (multi-site) Dithiocarbamate mancozeb Clevis*, Dithane, Fore, Junction*, Pentathlon, Protect, Zyban*
M5 (multi-site) Chloronitriles chlorothalonil Clevis*, ConSyst*, Concert II*, Daconil Ultrex, Daconil
Weatherstik, Echo, Exotherm Termil, Manicure 6FL, Spectro 90*, TM/C*
Not Classified Micorbial/Biopesticides Streptomyces griseoviridis Mycostop
Streptomyces lydicus (strain WYEC 108) Actinovate SP
Trichoderma harzianum Rifai strain Rootshield
Trichoderma harzianum T22, Trichoderma
virens G41
RootShield Plus*
Not Classified Inorganic Protectants botanical extract Neem Oil, Regalia
hydrogen dioxide Zerotol
hydrogen peroxide X3, Zeroton
potassium bicarbonate Armicarb 100, Kaligreen, Milstop
quaternary ammoniums KleenGrow
* Indicates a product that contains more than one active ingredient in a pre-pack mixture.
(Pest Control Material in bold typeface are from Syngenta.)
15.
16. 16 growertalks 2014-2015 Insecticide & Fungicide Guide
The wise and industrious Ben Franklin
once said, “An ounce of prevention is
worth a pound of cure.” In short, if we
take steps to prevent a problem, it’ll
save us a great deal more in time, effort
and expense than it would if we have to
correct or repair the problem later. While
this phrase can apply to many aspects of
our life, it also certainly applies to the
production of ornamental crops. The
expense of inputs (plants, seed, soil, pots,
water, fertilizer, energy and labor) is an
investment that needs to be protected. To
ensure plant quality and future sales, an
effective disease management strategy is
important and should include a preventive
fungicide rotation partnered with proper
cultural practices to reduce the risk of
disease.
While there are many different
fungicide products on the market,
they differ in their mode of action and
spectrum of activity. Fungicides are
classified as having protectant or curative
activity. Those that work through
contact with the pathogen are considered
protectants and work by preventing
infection. Fungicides with curative activity
have systemic or partially systemic activity
and can move within the plant tissue or
from the site of application to other areas
of the plant. Systemic fungicides tend to
have longer residual activity than those
that work through contact and can be
effective after an infection has occurred.
A fungicide strategy that contains both
contact and systemic products tends to
provide the best results.
Designing a disease
management strategy
Before making any selection of fungicides,
it’s important to have an understanding of
the parameters that can affect your crop.
Important questions to ask include:
n What diseases can affect the crops you’re
growing?
n When is the crop susceptible? That is,
what stage of plant growth, time of year or
environmental conditions are favorable to
the disease?
n How does the disease spread (air
movement, contact, insects, splashing
water/overhead irrigation)?
n Is the disease host-specific or can it
spread to surrounding plant material?
n What cultural changes can you
implement to minimize risk?
Many disease problems can be reduced
or eliminated with proper watering
practices, adjustments in relative humidity
and avoiding excessive soluble salts.
Important cultural tips to integrate in your
disease management program include:
n Clean growing area/greenhouse and
benches of all debris and sanitize between
crops.
n Irrigate early in the day to allow time
for the foliage to dry before evening.
n Provide good spacing of plants and flats
to allow for good air circulation and spray
coverage.
n Scout and rogue crop weekly for insect
and disease problems.
An effective disease management pro-
gram should include a built-in fungicide
resistance management strategy. After
identifying the primary disease problem
that can affect each crop in production,
select three to four fungicide products with
different modes of action that have proven
activity on each potential disease. You
may notice some fungicides have activity
across different diseases and utility across
multiple crops. This can help make your
product selection easier and help manage
inventory in your chemical shed.
Certain disease problems may be more
of a problem during different times of
production. Adjust your plan accordingly
and rotate among the products based
upon the label recommendations. Modify
your treatment interval based on disease
pressure and current environmental
conditions. Many of the newer fungicides
have broad application intervals. Keep
in mind that when making fungicide
applications in a preventive manner,
you can extend the treatment interval
based upon the label recommendations.
This can help save resources without
sacrificing quality. However, when disease
is already present in the crop, the shortest
application interval listed on the label
should be used. Remember to keep good
records; this will help provide a framework
for your strategy with future crops. GT
Nancy Rechcigl is a Technical Service
Representative for Syngenta.
Protecting Your Crops With Sound Disease Management
By Nancy Rechcigl
A close up of powdery mildew.
Cercospora lesions.
Stem rot on dianthus.
17. growertalks 2014-2015 Insecticide & Fungicide Guide 17
Know the diseases to which
your crop is prone
Recognize disease symptoms
Know the conditions that
cause diseases to develop
Understand disease management
ROOT AND CROWN ROT DISEASES
Pythium Root Rot Damping off; attacks root tips; lower leaves yel-
low and wilt; poor growth; nutrient deficiencies;
brown, limp roots—outer cortex sloughs off;
plant may die. Plant wilts during warm, sunny
days even with adequate moisture. Uneven
height or coloration within a crop.
Generally cool, wet substrate but depends on
Pythium species present. P. aphanidermatum
can be found at high temps; over fertilization
may predispose plants to infection. Produce
survival structures. Can be spread by irrigation
water.
Pathogen-free potting substrate; sterilized flats;
plant when soil and air temps are favorable for
rapid emergence; good drainage; careful irriga-
tion; sanitation. Make sure flat cells are filled
evenly. Preventative fungicide applications if a
history of disease.
Geranium, chrysanthemum, calibrachoa
Phytophthora Root
and Crown Rot
Infects roots and may move into crown and
stems; stunting of leaves and plant; leaves turn
yellow, wilt and may drop prematurely; plant
may die; roots turn dark and rot—outer cortex
sloughs off; may also be present with Pythium.
High substrate moisture more than 70%; gener-
ally cool temps (59 to 74F); wet substrate; over
fertilization generally predisposes plants. Wide
host range. Produce survival structures. Can be
spread by irrigation water.
Good drainage and water management; use
pathogen-free potting substrate, plants, water
and equipment. Preventative fungicide applica-
tions if a history of disease.
Gerbera, poinsettia, pansy, African violet,
lavender, annual vinca
Thielaviopsis Root Rot
(Black Root Rot)
Yellowing, stunted growth; signs of nutritional
deficiencies; root decay; wilting; roots develop
black lesions along root and root tips.
Moist, cooler (55 to 61F) substrates favor disease;
weakened/stressed plants are more susceptible;
Wide host range. Can be spread by fungus
gnats.
Sterilize containers, grow plant at pH most
favorable for the crop, good sanitation; discard
infected plants. Use preventative fungicide
applications for highly susceptible crops. Avoid
stressing crop.
Calibrachoa, pansy, petunia, annual vinca
Rhizoctonia Crown Rot Damping off; infection starts at crown and moves
up stem; constriction of stem; stem becomes
soft; plant may wilt; rotted crown (shredded,
dry-appearance); roots sometimes affected.
Brown, irregular-shaped spots can develop
on leaves and stems. Aerial web blight can
develop when the fungus grows from the potting
medium surface into the plant canopy. Fungus
grows in a radial pattern, so that infected areas
look like a circle or semi-circle of dead plants.
Web-like strands of the fungus can be seen when
humidity is high.
Drier substrate, but still wet (~40% water-hold-
ing capacity); humid and warmer conditions.
Wide host range. Survives in plant debris and
soil on benches, floors, pots, etc.
Discard infected plants (all plants in a flat). Apply
fungicides to protect visibly healthy plants. Avoid
placing plants directly on the ground. Irrigate
plants only when plants will dry quickly; increase
air circulation to reduce humidity. Clean pots and
production facility surfaces of dirt and crop de-
bris, followed by application of a disinfectant on
all surfaces. Use pathogen-free potting substrate;
good drainage; careful irrigation.
Chrysanthemum, celosia, garden and New
Guinea impatiens, poinsettia
Fusarium Wilt Lower leaves yellow and dry; can be followed by
rapid wilting of the entire plant or one side of the
plant in the case of chrysanthemums. Infected
plants wilt under moisture stress. On some hosts,
if stems cut open, the vascular system appears
reddish-brown. Yellowing and stunting of older
plants. Symptoms often expressed at time of
flowering. Damping off of seedlings.
High air and substrate temperatures (75 to 86F);
infected plants may appear symptomless at soil
temperatures less than 68F: can be spread by
infected but healthy-looking cuttings; fungus
may be present on seed coats. Drought or
flowering stress can result in rapid and severe
symptoms. Can be spread by fungus gnats.
Spores and fungal fragments move via irrigation
water. Produces survival structures.
Infected plants nearly always die. Remove crop
debris and disinfest between crops. Avoid reusing
trays and pots; use fungicides preventatively.
Chrysanthemum, cyclamen, gerbera, lisianthus,
pansy, annual vinca
Myrothecium Leaf Spot
and Crown Rot
Petioles rot at the soil line, leaf collapses. Leaf
spots initially appear water-soaked, and eventu-
ally turn brown or light tan in color. Diagnostic
symptom is the presence of raised, dark green-
to-black masses of spores surrounded by a fringe
of white fungal tissue. Spores typically produced
in a circular pattern on the leaf tissue.
Warm, moist, humid conditions favor infection
and disease development. Wounds are quickly
colonized by this soilborne fungus.
Remove and discard infected plants.
Highly susceptible crops should be carefully
scouted or fungicides applied on a preventative
basis. Remove plant debris between crops and
disinfect benches.
New Guinea impatiens, pansy, syngonium
(Susceptible plants in bold)
18. 18 growertalks 2014-2015 Insecticide & Fungicide Guide
Know the diseases to which
your crop is prone
Recognize disease symptoms
Know the conditions that
cause diseases to develop
Understand disease management
Bacterial Soft Rot
(Pectobacterium=Erwinia)
Watery decay of plant tissue at the soil line; foul
odor; collapse of plant (meltdown).
Requires high humidity to infect. Bacterium is
ubiquitous in environment. Increased irrigation
increases severity of the disease. Excessive
nitrogen increases disease on calla lily.
Immediately discard infected plants. Porous
substrates have been reported to decrease
disease on calla lily. Copper dips are effective for
about 6 weeks.
Calla lily, cyclamen, primrose, bulb crops
Sclerotinia Blight
(White Mold)
Water-soaked spots on the stems or leaves
become covered in a white cottony mass of
fungal mycelium. Plant becomes soft and slimy.
Hard black structures (sclerotia ) develop within
the fungal mass. May also cause dry lesions that
girdle the stem; sclerotia form within the stem.
Spread is primarily by airborne ascospores. High
soil moisture, high humidity and cool tempera-
tures (50 to 75F) favor disease development.
Difficult, if not impossible, to control once infec-
tion has occurred.
Lobelia, marigold, petunia, zinnia
FOLIAR AND STEM DISEASES
Anthracnose Anthracnose is a catch-all term for leaf spot
or stem canker symptoms caused by several
different fungal species. Affected tissue dies.
Colletotrichum forms masses of pinkish-orange
spores within the lesions or stem cankers.
Warm, moist conditions with high humidity
favor disease development.
Minimize duration of leaf wetness through en-
vironmental modification and cultural practices,
such as irrigation and plant spacing. Preventative
fungicide applications may help to reduce new
infections and spread. Pathogen populations of
Colletotrichum species resistant to thiophanate-
methyl have been found.
Begonia, cyclamen, osteospermum, pansy
Botrytis Leaf Blight
(gray mold)
Symptoms vary with host and tissue invaded;
leaf spots; bud rot; flower blight; cutting rot;
stem canker, stem and crown rot; proliferation of
fluffy, brown/gray fungal mycelium containing
spores; damping-off.
High humidity more than 85%; poor air
circulation; 70 to 77F optimum temp for spore
germination; spores must have free moisture to
germinate; old flowers and decaying vegetation
source of spores; rapidly colonizes wounded
tissue.
Keep relative humidity below 85%; do not allow
leaves to stay wet for more than 6 hours; provide
good air circulation around plants; remove
infected plants; strict sanitation to remove spent
flowers and old leaves; fungicides alone will not
control Botrytis.
Cyclamen, geranium, poinsettia, rose
Powdery Mildew Fluffy white patches on upper leaf surface,
turning gray with age. Can also infect stems and
flower petals when severe.
Favored by warm days and cool, damp nights;
free water inhibits spore germination. This
fungus can infect at low relative humidity.
Must be detected early, as this disease can spread
quickly. Susceptible crops should be treated with
a fungicide prior to development of powdery
mildew. Increase air movement, reduce humidity.
Gerbera, petunia, rosemary, rose, verbena
Downy Mildew White/purple/gray fuzz (spores) on undersides
of leaves. Yellowish or pale green mottling on
upper leaf surface. On garden impatiens, foliage
appears to have yellow stippling similar to
spider mite injury. Downward curling of leaves.
Emerging leaves may be small or discolored. Can
become systemic in plants, resulting in stunting
or distorted new growth.
Favored by high humidity, long durations of leaf
wetness and cool weather (60 to 74F daytime).
Can survive in plant debris in soil. Spores are
spread by splashing water and air currents.
Increasingly detected during warm months and
in warmer regions.
Immediately discard infected plants and adjacent
plants. All remaining plants on premises should
be treated with a fungicide. Fungicides are used
to prevent spread to non-infected plants and to
new growth when symptoms first appear (apply
frequently with good coverage). Fungicides will
not cure an already infected plant. Keep relative
humidity below 80 to 85%. Do not reuse pots
from diseased plants.
Bracteantha, coleus, garden impatiens, snap-
dragon, veronica
19. growertalks 2014-2015 Insecticide & Fungicide Guide 19
Know the diseases to which
your crop is prone
Recognize disease symptoms
Know the conditions that
cause diseases to develop
Understand disease management
Fungal leafspot diseases
(Alternaria, Cercospora,
Septoria, Phyllosticta)
Round to irregular leaf spots; often with a border
(red/purple/brown). Center of lesions becomes
tan with age; size of lesion increases over time.
Fruiting bodies may be present within lesion.
Prolonged leaf wetness, high humidity and
warm temperatures favor most fungal leafspot
diseases.
Minimize leaf wetness. Scout frequently. Fungi-
cide applications.
Geranium, impatiens, pansy, zinnia, many
perennials
Rust Yellow, orange or brown spore masses or
pustules form on the underside of the leaf and
erupt through the leaf tissue. On geranium and
snapdragon, the pustules are formed in a target
pattern.
Infect under mild, moist conditions. Spores
easily spread in air currents.
Minimize the time foliage stays wet. Discard
infected plants as soon as they're detected. Pro-
vide good air circulation and don’t crowd plants.
Fungicides applied at the first sign of infection
can help prevent serious damage.
Aster, fuchsia, geranium, snapdragon
Bacterial Leaf Spot
(Pseudomonas sp.,
Xanthomonas)
Small, round, water-soaked lesions sometimes
surrounded by a purple or yellow halo on leaves.
Lesions often vein-delimited. Lesions initially
yellow or light green, quickly progressing to dark
brown or black (lesions may turn tan with age).
Lesions may rapidly enlarge and entire leaf will
rot. Infection may follow the petiole down to
the crown.
High humidity, wet leaf surfaces. Splashing
water moves bacteria and allows infection of
new leaves. Reducing nitrogen may reduce dis-
ease caused by Pseudomonas. Insects (fungus
gnats, shore flies, leaf miners) and pruning may
spread bacteria.
Discard infected plants and leaves showing
symptoms. Surface-disinfect clipping shears,
tools and benches between plantings. Monitor
humidity; reduce free moisture on leaves; bacte-
ricides may help reduce spread, but are generally
not very effective; preventative applications may
mask symptoms and still not control disease.
Irrigate when leaves will dry quickly. Drip irriga-
tion or ebb & flow will help to control some leaf
spot diseases.
Reiger begonia, English ivy, geranium, gerbera,
poinsettia, zinnia
Viruses:
INSV
(Impatiens necrotic spot virus)
TSWV
(Tomato spotted wilt virus)
Symptoms vary with host; yellow or necrotic
spots on stems or leaves; leaf mosaic; black leaf
spots; black ring spots; line patterns, overall
yellowing; stunting.
Transmission from infected to healthy plants
via thrips; introduction into the greenhouse via
infected plants or insect vector.
Careful monitoring and management of thrips
population; inspection and isolation of new plant
materials; purchase material certified virus free;
weed management; avoid carrying over stock
plants unless tested free of viruses.
Many ornamental hosts
Viruses:
HVX (Hosta Virus X)
Symptoms highly variable depending on cultivar.
Major leaf veins may take on a feathered ap-
pearance at the edges, resulting in a “bleeding”
appearance. Extreme symptoms include severe
necrosis and death of leaves.
No evidence this virus is transmitted by insects.
Vegetative propagation most important means
of spread.
Some reported differences in cultivar susceptibil-
ity. Tiara series, Blue Cadet and Honeybells
are highly susceptible. Purchase plants from a
reputable source. Sanitize tools often and avoid
mixing lots from different sources.
Hosta
Foliar Nematodes Pattern of damage is dictated by the pattern of
major leaf veins (i.e., stripes, patchwork). Nema-
todes enter leaf cells through wounds or natural
openings. Plant tissue initially turns yellow and
eventually brown and necrotic. Symptoms often
not visible until nematode population becomes
quite large.
Spread by vegetative propagation, splashing
water, plant-to-plant contact, worker move-
ment and tools.
Exclusion is the most effective method of
management. Inspect plant materials before
introduction. Separate dormant materials until
new growth has emerged and can be inspected
for symptoms. Plants confirmed with foliar
nematodes should be promptly discarded.
Chemical control is highly variable, with limited
effectiveness.
Many herbaceous and woody perennials
(Susceptible plants in bold)
20. 20 growertalks 2014-2015 Insecticide & Fungicide Guide
Bugs eating bugs has been going on since
the beginning of time. Until recent years,
this hasn’t been something that commercial
growers have really relied on as a weapon in
their arsenal, but with the many concerns
facing our industry today, growers are look-
ing to use biological control as a way to
combat their pests.
Why are growers choosing to incorpo-
rate biological control agents (BCA) into
their pest management program? One
driving factor has been managing pesticide
resistance. This could be growers encoun-
tering pests that were resistant to pesticides
(and not being able to control them) or
using the BCAs to proactively help pre-
vent developing pesticide resistance. Other
reasons BCAs are gaining popularity are
environmental concerns, worker safety,
the convenience of zero
re-entry intervals, and
in some cases, simple
economics. Recently
though, a new factor has
been prompting more
commercial growers to look at biocontrol—
social pressures. The use of neonicotinoids
has been coming under scrutiny and some
growers are under pressure to reduce the use
of this class of pesticides. The result is that
some companies are looking for alternatives
to this class of chemistry. One viable alter-
native is to use BCAs.
Know your enemy
When starting with a biological control
program it’s critical that you properly iden-
tify your pests before you start. Don’t guess,
or assume—you MUST have POSITIVE
ID! Biological control often is going to
require a more specific level of identifica-
tion than traditional spray programs may
require. With traditional chemical appli-
cations, often just knowing what type of
insect you have is enough. For instance, you
might have only had to know that your pest
was a whitefly, aphid or thrips, but that may
not be enough for a successful biocontrol
program. In order to select the right control
agent for your situation, one may often
need to know the specific species of aphid
or specific species of whitefly you have.
Assuming that an aphid is an aphid is not
enough. Don’t worry—you don’t have to go
back to school to get an advanced degree in
entomology in order to get positive identifi-
cation. There are many resources out there
that can help you with positive ID and you
can always ask your local extension office.
Why is accurate identification of your
pest so important for biological control?
Because some beneficials are host-specific
to their pests (this is more true for parasites
than predators). Take for example the cot-
ton/melon aphid, Aphis gossypii. If you find
this pest in your greenhouse and want to
treat using biological control agents, you
could use the parasitic wasp Aphidius cole-
mani.
But let’s say instead you have the potato
aphid, Macrosiphum euphorbiae. You (or the
biocontrol company you’re dealing with)
will need to know that Aphidius colemani
won’t work that well on that particular
aphid species. You would want to get
Aphidius ervi or even Aphelinus abdomina-
lis; these parasites prefer the potato aphid.
There are increasing numbers of different
aphid parasites commercially available, so
it’s important to match the correct benefi-
cial with your pest. This information can be
supplied by your biological control supplier.
Using beneficials
Once you know exactly what your target
pests are, you’ll need to check the spray
records for the specific crop over the last
three months. This may mean asking for
spray records from your liner or plug sup-
plier. Some pesticides, such as synthetic
pyrethroids, have extremely long persistence
periods. From the date of the application
of the pyrethroid, you’ll need to wait eight
to 12 weeks before your first BCA release.
What can you do in the meantime? Your
supplier or crop consultant can help put
together a spray program of products that
have shorter persistence times, getting you
ready for your first release.
Once you get your beneficials out there
working for you, don’t think that you can-
not use pesticides at all. It’s simply not
true. While pesticides can be a compatible
option, it’s not as if you can just spray any
product on your beneficials before doing
your homework. There are definitely some
products that can cause problems. Thank-
fully, many of the newer products on the
market today are softer on most beneficials,
and if used intelligently, they can be suc-
cessfully incorporated as a tool in your pest
management program alongside the ben-
eficials.
To figure out the chemical compatibility
information, you’ll need to know the active
ingredient in the product you’re considering
applying, as well as how you’ll be applying
it (drench, spray, etc.). You’ll also need to
know the scientific name of the BCA you’re
using. This information can be plugged into
tables provided by the biological control
companies or by asking your supplier. Don’t
make an assumption that just because one
product is compatible with one specific
BCA that it’ll be compatible with all others.
Always check for each beneficial and active
ingredient before treating. This will include
not only insecticides, but fungicides as well.
Details are important here.
When to use pesticides
When are pesticide sprays needed in a bio-
control program? Sometimes it’s right when
you’re getting started. Remember, biological
control is not a curative; it’s a preventative
program. BCAs need to be released when
pest levels are low or sometimes when the
pests aren’t even present yet. I say “yet” be-
cause they do come every year—the thrips,
aphids, whiteflies and so on. If you can get
the beneficials out first, then sprays may not
be necessary. If you do need to spray, try to
select products, such as soaps or oils, where
beneficials can be released once the sprays
dry. The last thing you want to do when
starting a bio program is shoot yourself in
the foot by using a pesticide with a long
spray residual that might kill the beneficials
you’re releasing.
Sometimes even if you do everything
right, the pest population can climb beyond
the control of the BCAs. If this happens, a
cleanup or spot spray may be needed (using
a compatible product) to help reduce the
pest population.
Another time a pesticide spray may be
needed is if a new pest pops up for which
there’s not a predator or parasite com-
mercially available. Sometimes this can
Biological Control in Production
By Suzanne Wainwright-Evans
Neonicotinoids are a class
of neuro-active insecticides
chemically similar to nicotine.
They’re found in several
commercial pesticides today.
21. growertalks 2014-2015 Insecticide & Fungicide Guide 21
happen when applications of broad-spectrum
pesticides aren’t being used anymore. First, as
always, make sure to accurately identify the
newcomer, making sure it’s not a beneficial. It’s
not uncommon for growers to make every ef-
fort to kill a new insect, when in fact it may be
a volunteer predator. Once you have a positive
identification, select a product that you can
apply with minimum impact of your ongoing
beneficial program (your biological supplier
can help you with this).
Biological control in commercial produc-
tion greenhouses is still a new emerging sci-
ence. I don’t think anyone will deny that the
advancements in just the last 10 years have
been great ones. Many growers are running
successful programs controlling Western flower
thrips, spider mites, aphids and other pests of
economic importance. When getting started,
growers just need to realize they’ll have to learn
a lot, but it’ll pay off in the end. GT
n When on a bio program, native beneficials often show up to work for free for you. Be sure not to kill them with sprays.
n Watch for pesticides that are incorporated into media. They can impact some of the BCAs.
n Beneficial nematodes do well under mist systems in propagation.
n Get your beneficials in early, before you have a pest problem.
n Scouting is critical. You must know what’s going on in your crop!
Aphid Biological Control Agents
Aphidius matricariae
(parasite, wasp)
Aphidius colemani
(parasite, wasp)
Aphidius ervi
(parasite, wasp)
Aphelinus abdominalis
(parasite, wasp)
Aphidoletes aphidimyza
(predator, midge)
Chrysoperla sp.
(predator, lacewing)
Green peach Myzus persicae yes yes somewhat somewhat
Attacks over 60 species of
aphids.
Attacks most species of aphids
that live on the foliage.
Cotton/ Melon Aphis gossypii no yes somewhat no
Potato Macrosiphum euphorbiae no no yes yes
Foxglove Aulacorthum solani no yes yes
Tobacco Myzus nicotianae yes yes
Rose Macrosiphum rosae yes yes
Western Flower Thrips (WFT) Biological Control Agents
Amblyseius cucumeris
(predator, mite)
Amblyseius swirskii
(predator, mite)
Amblydromalus limonicus
(predator, mite)
Hypoaspis miles (Stratiolaelaps scimitus)
(predator, mite)
Orius insidiosus
(predator, insect)
Atheta coriaria
(predator, insect)
Steinernema feltiae
(parasite, nematode)
Western Flower
Thrips (WFT)
Frankliniella
occidentalis
Early instars on plant Early instars on plant Early instars on plant Pupa in soil
Immatures and
adults on plant
Pupa in soil Pupa in soil
Fly Biological Control Agents
Steinernema feltiae
(parasite, nematode)
Steinernema carpocapsae
(parasite, nematode)
Hypoaspis miles (Stratiolaelaps scimitus)
(predator, mite)
Atheta coriaria
(predator, insect)
Fungus gnats Bradysia sp yes yes yes
Shore Flies Scatella sp. yes
Whitefly Biological Control Agents
Encarsia formosa
(parasite, insect)
Eretmocerus eremicus
(parasite, insect)
Eretmocerus mundus
(parasite, insect)
Delphastus catalinae
(predator, insect)
Amblyseius swirskii
(predator, mite)
Amblydromalus limonicus
(predator, mite)
Chrysoperla sp.
(predator, insect)
Greenhouse Whitefly
Trialeurodes vaporariorum
yes yes yes yes yes Will feed but not control
Sweet Potato / Tobacco
Bemisia tabaci
yes yes yes yes yes Will feed but not control
Spider Mite Biological Control Agents
Phytoseiulus persimilis
(predator, mite)
Amblyseius californicus
(predator, mite)
Amblyseius fallacis
(predator, mite)
Amblyseius andersoni
(predator, mite)
Feltiella acarisuga
(predator, insect)
Chrysoperla sp.
(predator, insect)
Spider mite species yes yes yes yes yes Will feed but not control
Leafminer Biological Control Agents
Diglyphus isaea
(ectoparasitic,
insect)
Dacnusa sibirica
(endoparasitoid,
insect)
Leafminer species yes yes
Tips
Suzanne Wainwright-Evans is an Ornamental
Entomologist specializing in integrated pest
management and owner of Buglady Consulting.
An Orius insidiosus release box.
23. growertalks 2014-2015 Insecticide & Fungicide Guide 23
Integrated Crop Management (ICM) is
the comprehensive and coordinated use of
cultural, biological and chemical tactics to
reduce pest populations to acceptable levels.
Successful ICM programs are those that have
been well thought-out then customized for
individual needs. Gathering information
before, during and after a program is essen-
tial to perfecting the strategy and achieving
continued success, year after year.
To begin an ICM program, it’s essential
to evaluate cultural practices, gather infor-
mation on crops, and scout and examine
environmental conditions. Growers should
compile historical data on pests, diseases
and resistance issues, as well as chemicals,
biological control agents (BCAs) and other
treatments used in the growing area. All
ICM programs, including BCAs, are best
implemented preventively. Understanding
your crop and potential pest pressure is im-
perative.
Elements of a successful ICM program
n Scouting
n Monitoring
n Good record keeping
n Realistic expectations
n Dedication
n Communication at all levels
n Flexibility
n Preventative cultural practices
Unfortunately, ornamental pest activity
doesn’t follow a calendar. Scouting is the key
to any successful ICM program. The decision
to implement a scouting program is one that
can weigh heavily on the minds of grow-
ers. Production facilities that don’t utilize
a scouting program often rely on broad-
spectrum calendar sprays and/or “curative”
applications to gain control of established
pest populations. Calendar spraying can
result in unnecessary and costly pesticide
applications and may accelerate the develop-
ment of pesticide resistance. Last minute or
curative applications are often not successful,
resulting in multiple applications and/or an
unsellable crop.
Scouting is the only way for a grower to
have an intimate knowledge of his crop and
potential disease and pest pressures.
For a scouting program to be successful,
there must be people devoted to scouting
regularly. Look at all crops weekly and on
the same day each week to avoid missing
significant outbreaks. Many pest life cycles
during periods of higher temperatures may
be completed within seven days or less.
Scouting is an important job and cannot be
done appropriately with a hit-or-miss ap-
proach. It’ll be difficult to detect and identify
pest problems early in the infestation cycle
without a good scouting program in place.
Scouting methodology
The first important step in scouting is to
thoroughly inspect all newly arriving plant
material for any hitchhikers.
Utilize yellow sticky cards to monitor
flying insect pests. For specific monitoring
of thrips, blue sticky cards may be used. At
a minimum, evaluate sticky cards weekly to
monitor adult populations and determine
appropriate application and timing of con-
trol options. One sticky card every 1,000 to
3,000 sq. ft. is usually sufficient. Sticky cards
may also be used to monitor populations
two to three days after a pesticide application
to ensure proper control was achieved. Sticky
cards are a very useful scouting tool, but take
care not to rely solely on them for moni-
toring pest populations. Without careful
incorporation of multiple scouting methods,
instances of minor disease and insects/mites
are often missed.
When scouting, look for obvious signs
of plant damage, such as chlorotic, stunted
or malformed growth, cast off skins, feeding
damage, honeydew, sooty mold and the pres-
ence of ants. Using a hand lens, check un-
dersides of leaves from the top to the bottom
of the plant to detect infestations before they
cause severe plant damage. Take hanging
baskets down and inspect from sides and top
to ensure devastating populations of spider
mites, thrips or aphids don’t go unchecked.
Just as a successful ICM program requires
a good scouting program, scouting without
proper record keeping will be ineffective.
Growers who attempt to diagnose a problem
without records are at a disadvantage and
may overlook potential causes of the prob-
lem. Scouting data isn’t very useful if the
problem sites aren’t clearly noted, showing
where disease, mite and insect infestations
are located in the growing area. A good way
to organize the scouting data is to summarize
the information for each growing area, ac-
cording to the pests detected, the counts and
any unusual circumstances discovered. Infor-
mation generated by scouting can be used to
determine if pests present are above or below
action thresholds to make effective pest
control decisions. As the season progresses,
growers will observe pest trends developing
within the scouting data, which will allow
improved pest management decisions.
Scouting must continue after pesticide
and/or BCA application to make sure pest
management practices are successful. Choos-
ing an insecticide or BCA that’s effective
for the pest life stage present and fits into a
proper rotation is essential. Keeping detailed
records of any pesticide application or BCA
release is very helpful when comparing previ-
ous pest management practices and evaluat-
ing if fewer control applications are necessary
or more efficacious chemical or biological
controls should be substituted.
Implementing a scouting program takes
time and patience. Adequate time must be
invested into the production of a crop and
detailed records must be kept. Over time,
growers can determine their own economic
threshold for any given insect, related pest
or disease, allowing better decisions for pest
control. Early detection by scouts will allow
growers to substitute or incorporate a tar-
geted insecticide or BCA application before
pest populations reach unmanageable levels.
This will also help decrease the likelihood
that pests will develop resistance, which will
allow the grower to maintain effective prod-
ucts in their arsenal against pests.
Results with any particular program will
depend on many factors, including time of
year, number of applications, environmen-
tal conditions and specific products used.
Releases of BCAs and chemical applications
should be based on particular scouting/
monitoring programs. GT
Marla Faver specializes in technical service for
ornamental production and can be reached at
paintedskygsp@gmail.com.
Scouting for Success with Integrated Crop Management
By Marla Faver
