Organic Pesticides

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Organic Pesticides

• by samantha snyder

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Since I retired

• Raising chickens
• KTOK 1000 AM
• OSU-OKC
• Horticulture Consulting
• www.okcgardentutor.com

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Why talk about organics?

• Lack of training on the topic
• Available info is either limited or overwhelming
• Personal interest

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Digging through the dirt

• There is information out there on everything
• What to trust and recommend as organic

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What does organic mean to you?
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• No chemicals
• No man-made chemicals
• Only plant derived products
• Homemade products

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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.

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• Organic growers work in conjunction with
  Government Certifiers to maintain compliance with
  National Organic Standards.
• OMRI is the safe list

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Common Organic Pesticides

• Bt or Bacillus thuringiensis
• Copper
• Neem
• Pyrethrum
• Oils

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Organic pesticides are safe for me and the
environment.

• True or False?

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Organics are safe for me and the environment.

• False!!!
• safe
• Signal Words????

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Bt Caution

• Non Synthetic
• AI- proteins produced by Bt bacteria
• Spore forming bacteria
• Common in terrestrial habitat
• Soil, dead insects, plants, granaries

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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

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Bt know your Latin

• Imperative to match subspecies with pest
• Bt kurstaki Lepidoptera
• Bt tenebrionis Coleoptera
• Bt israliensis - Diptera

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Residual Effect

• Only a few days
• Broken down by sunlight
• Can be used with stickers or UV blockers

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Best control

• Early detection
• Proper application
• Timing
• Location
• Pest compatibility

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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 Bts crosses of wild types
  (Dipel,Javelin) Also NOT OMRI approved
• Bt corn/cotton, Not OMRI approved

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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

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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

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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

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• 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

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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

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Green Aspect

• Small amounts of Cu are needed for plant and
  animal life. Excessive amounts are dangerous
• Leaf persistence
• Can remain for 1-2 weeks
• Or until it is washed off (rain, irrigation)

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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

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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

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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!!!

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Neem (caution, warning)

• Non-synthetic botanical pesticide
• Derived from the neem tree, Azadiracta indica
• Native to southern Asia (sub-tropical/tropical)
• Cure of all ailments
• Used for centuries for medical, cosmetic and
  pesticidal purposes

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Research

• As early as 1920
• 1959 German ento noticed that neem trees in the
  Sudan resisted an attack of migratory locust

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How its 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

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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

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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)

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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

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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

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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

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Oils (caution)

• Synthetic and natural
• AI 3 types
• Petroleum (mineral)
• Fish
• Plant
• Petroleum has the most available info and has
  been developed the most

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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

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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)

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Phytotoxicity

• Visible leaf damage or yield reduction
• The slower the oil evaporates, the higher the
  risk of damage
• Avoid application on humid days

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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

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• Natural enemies Can kill beneficial mites and
  cause flare up in population
• Humans low toxicity to those applying,
  typically gone by time of harvest

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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

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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

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Rums and Roids

• Pyrethroids are synthetic compounds
• Mode of action is similar
• But not OMRI approved

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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

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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

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• This may be one example of an oil synergist
• Not sure if it is OMRI approved
• Found at Horns

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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

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Green aspect

• Little to no leaf persistence
• Broken down in water to nontoxic products
• Soil persistence 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

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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

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Efficacy

• Victims
• True bugs, caterpillars, beetles, aphids, flies,
  mites, whiteflies, thrips and leafhoppers

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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

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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

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