Organic Pesticides - Oklahoma State University–Stillwater
Download
Report
Transcript Organic Pesticides - Oklahoma State University–Stillwater
Organic Pesticides
by: samantha snyder
Since I ‘retired’…
Raising chickens
KTOK 1000 AM
OSU-OKC
Horticulture Consulting
www.okcgardentutor.com
Why talk about organics?
Lack of training on the topic
Available info is either limited or
overwhelming
Personal interest
Digging through the dirt
There is information out there on
everything
What to trust and recommend as ‘organic’
What does organic mean to you?
No chemicals…
No man-made chemicals…
Only plant derived products…
Homemade products…
Organic Materials Review Institute
Founded in 1997, the Organic Materials
Review Institute (OMRI) provides organic
certifiers, growers, manufacturers, and
suppliers an independent review of products
intended for use in certified organic
production, handling, and processing. OMRI
is a 501(c)3 nonprofit organization. When
companies apply, OMRI reviews their
products against the National Organic
Standards. Acceptable products are OMRI
Listed® and appear on the OMRI Products
List.
Organic growers work in conjunction with
Government Certifiers to maintain
compliance with National Organic
Standards.
OMRI is the ‘safe list’
Common Organic Pesticides
Bt or Bacillus thuringiensis
Copper
Neem
Pyrethrum
Oils
“Organic pesticides are safe
for me and the evironment.”
True or False?
“Organics are safe for me and the
environment.”
False!!!
‘safe’
Signal Words????
Bt – “Caution”
Non Synthetic
AI- proteins produced by Bt bacteria
Spore forming bacteria
Common in terrestrial habitat
Soil, dead insects, plants, granaries
How Bt works
MUST be eaten by susceptible pest
Endotoxin binds to gut creating a hole/pore
Contents enter the body cavity/bloodstream
No immediate knock-down
But does slow feeding
Bt – know your Latin
Imperative to match subspecies with pest
Bt kurstaki – Lepidoptera
Bt tenebrionis – Coleoptera
Bt israliensis - Diptera
Residual Effect
Only a few days
Broken down by sunlight
Can be used with ‘stickers’ or UV blockers
Best control
Early detection
Proper application
Timing
Location
Pest compatibility
Other info
Resistance is a problem
CO Potato Beetle – No OMRI approved products available
100 Bt microbial insecticides registered
Based on 4 subspecies
Very available, but…
Some may have inert ingredients that are NOT OMRI
approved
Hybrid Bt’s – crosses of wild types (Dipel,Javelin)
Also NOT OMRI approved
Bt corn/cotton, Not OMRI approved
The ‘green’ aspect of Bt
Humans – Gut structure completely different
Rapid UV breakdown
Wildlife
Fed to birds and fish – no adverse effects
Natural Enemies
Parasites and predators – not harmed directly, but loss
of host site could be a problem
NonTargets
Other moths and butterflies
Copper Products –
“Danger, Warning & Caution”
Mineral based fungicide/bactericide
Considered synthetic
Allowed
Fixed coppers – minimize accumulation in soil
Copper hydroxide, copper oxide
Copper sulfate
Terrestrial
Aquatic
How Copper works
Cu ions disrupt the functions of proteins
after being absorbed into fungus or
bacterium
‘Non-specific denaturation of cellular
proteins
Best absorbed by germinating fungal
spore
Multiple applications typically necessary to
protect new plant growth
Cu is more soluble (releases Cu ions) in
low pH
If applied with water pH lower than 6
phototoxicity can occur
Bordeaux mixes are Copper Sulfate and
hydrated lime to avoid this efffect
Efficacy
Listed on over 100 crop plants to control
fungal and bacterial diseases
More effective on bacterial than fungal, but
widely recommended for both.
Tomatoes, Pines, Algae
‘Green’ Aspect
Small amounts of Cu are needed for plant
and animal life. Excessive amounts are
dangerous
Leaf persistance
Can remain for 1-2 weeks
Or until it is washed off (rain, irrigation)
Fate in water and soils
Because it is so soluble, leaches well
Also binds tightly to soil
So only leaches well in very sandy soils
Very high levels have been found in ag
settings after only a few decades
Wildlife
Practically non-toxic to birds
Highly toxic to fish – especially in acid
water
Bees – endangered by bordeaux mix
Poison to sheep and chickens
As soil levels build, soil life diminishes
Worms, Rhizobium bacteria, etc
Will also control all forms of Bt
Human aspect
“Vineyard sprayers experienced liver
disease after 3-15 years of exposure to
copper sulfate solution in Bordeaux
mixture.”
Nasty stuff!
Vomiting normally triggered instantly, but
acid conditions of stomach encourage
absorption.
Be cautious!!!
Neem (caution, warning)
Non-synthetic botanical pesticide
Derived from the neem tree, Azadiracta
indica
Native to southern Asia (subtropical/tropical)
Cure of all ailments
Used for centuries for medical, cosmetic and
pesticidal purposes
Research
As early as 1920
1959 – German ento noticed that neem
trees in the Sudan resisted an attack of
migratory locust
How it’s made
Crushing neem tree seeds
Water or solvent such as alcohol to extract
pesticidal constituents
Different extraction process leads to
different amounts of chemical present
Efficacy of different products may vary
Neem cake is residual seed – used as
fertilizer
How it works
AI – Azadirachtin, one of the more than 70
compounds produced by the neem tree
Acts as an IGR and anti-feedant and
oviposition deterrent
Works by contact or ingestion
Prevents molting (inhibits ecdysone production)
Stops feeding – physiological effect
Egg laying – volatile compounds repel insects
General application guidelines
Multiple applications
Broken down by UV and washed off easily
Use on immature insects
Use on low populations
Works best under warm temperatures
Apply to transplants before planting
Systemic properties are better than foliar
applications (drench)
‘Green’ aspect
Breaks down within 100 hours of light or
water – mix and use
Wildlife – relatively non-toxic
Natural enemies – little or no effect on
adult beneficials
Relatively harmless to: bees, spiders,
ladybeetles parasitoid wasps, and adult
butterflies.
Suitable for IPM inclusion
‘green’ continued
Non target organisms – generally nontoxic
Neem leaves added to the soil increased
earthworm weight and survival
More research needed
Human effects – likely does not pose a
significant risk
Irritation to mucous membranes from seed dust
Most studies done on azadirachtin – not entire
neem product
Efficacy
Affect over 200 insect species
Whiteflies, thrips, leafminers, caterpillars
aphids, scales, beetles, true bugs and
mealybugs, squash bugs, etc.
Efficacy can vary on species
Oils (caution)
Synthetic and natural
AI – 3 types
Petroleum (mineral)
Fish
Plant
Petroleum has the most available info and
has been developed the most
How it works
Pet Oils – control the egg stage by
interfering with gas exchange or egg
structure
Other stages, can block respiratory system
or cuticle break down
Plant and fish probably similar
All oils could disrupt insect behavior –
feeding,oviposition
Plant vectored virus control – stylet oil
Pests controlled
Soft bodied insects
Aphids, mites, thrips, whiteflies, mealybugs,
psyllids
“the only widely used class of pesticides to
which insects or mites have not developed
resistance.” (Sams and Deyton 2002)
Phytotoxicity
Visible leaf damage or yield reduction
The slower the oil evaporates, the higher
the risk of damage
Avoid application on humid days
‘Green’ aspect
Pet oils used on plants are light weight
and generally evaporate quickly.
Effects of vapors not known
Negligible ability to contaminate soil or
groundwater
Plant and Fish oils not as volatile, but
break down quickly by microbes
Unlikely to have any effect on wildlife or
non target species
Natural enemies –Can kill beneficial mites
and cause flare up in population
Humans – low toxicity to those applying,
typically gone by time of harvest
Efficacy
Long history of dormant spray in fruit crops
to control mites and scale
Less experience with vegetable crops
Generally found to be more effective when
mixed or used in combination with another
pesticide
Pyrethrum (caution)
Botanically derived
Non-synthetic
Powdered, dried flowerheads of the
pyrethrum daisy chiefly, Chrysanthemum
cinerariaefolium
Native to SW Asia, Kenya is leading
producer then Australia
Rums and Roids
Pyrethroids are synthetic compounds
Mode of action is similar
But not OMRI approved
How it works
Fast acting contact poison that ‘knocks
down’ susceptible insects
Effects nervous system
Repetitive nerve discharges
Left paralyzed by toxic effects
If dose is too low, some insects can
recover
Synergists
Enhanced mortality
Adding a non-insecticidal chemical
heightens response
Reduces ability to detoxify pyrethrum
PBO – piperonyl butoxide is common but
not OMRI approved
Use care when shopping
Others are now adding oils
This may be
one example of
an oil synergist
Not sure if it is
OMRI approved
Found at Horns
Application Tips
Broken down by both acid and alkaline
solutions : do not mix with lime, sulfur or
soap
Rapidly broken down by UV
Contact poison
Spray flying insects (cuc beetle) in early
morning while less active and before bee
activity
‘Green’ aspect
Little to no leaf persistance
Broken down in water to nontoxic products
Soil persistance – half life of 1-2 hours
Indoors – can persist up to two months in
carpet dust
Wildlife – Extremely toxic to fish, slightly to
birds.
Unlikely to concentrate in food chain:
easily metabolized
‘Green’ cont
Beneficial arthropods – broad spectrum,
but low residual
Highly toxic to bees
Humans –relatively nontoxic to humans,
still use with ‘caution’
Can easily be inhaled
Efficacy
Victims
True bugs, caterpillars, beetles, aphids, flies,
mites, whiteflies, thrips and leafhoppers
Moral of the story…
Know the pest
Know the plant
Know the options
Use caution with any pesticide
None of them are ‘safe’
Be it organic or synthetic
Resource
Resource Guide for Organic Insect and
Disease Management (Oct 2005)
ISBN number 0-9676507-2-0
Collaboration
NorthEast Organic Network
Cornell University
OMRI
EPA
Maine Organic Farmers Assoc
Sustainable Agriculture Research and Education
Program
The Garden Tutor
www.okcgardentutor.com
405-742-7919