Alternatives to Pesticides - Urban and Community Horticulture


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Alternatives to Pesticides - Urban and Community Horticulture

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Alternatives to Pesticides - Urban and Community Horticulture

  1. 1. 2/15/2009 Number of Species Currently Controlled with Pesticides Diseases 137 Home Garden Seminar Josephine County Master Gardeners Insects 304 Mites 34Alternatives to Pesticides Nematodes 23 Gail Langellotto Urban and Community Horticulture Specialist Weeds 102 OSU Extension and Department of Horticulture Agricultural Effects upon Conservation Biological Control Diversity Equilibrium 40 • Few studies have been conducted in garden 30 systems 20 – Exception: Shrewsbury and Raupp (2006). Do top-down versity 10 or bottom up forces determine Stephanities pyriodes in 0 urban landscapes? pDiv -10 Two Dimensional System Three Dimensional System -20 -30 -40 Pristine Conventional Alternative "Natural" Agriculture Agriculture Components Landscape Natural Disease Ecology Pest Enemies Complex Complex • Raupp et al. 2001. Plant species diversity and abundance affects the number of Management arthropod pests in residential landscapes. Land Plant Abiotic Land Diversity Factors Soil Soil Nutrients Organic Nematodes Matter Micro/ Macro Microbial Inverte- Flora brates 1
  2. 2. 2/15/2009 Climbing the Alternatives Ladder Principles of IPM Regional Integration • Prevent Problems Level III Systems Integration • Monitor the plants Level II • Identify the pest organism y p gMulti-species / Multi-tacticMulti- Multi- • Establish an acceptable injury Level IIntegrated Strategies threshold • Manage using all available Multiple Tactics strategies Pesticides Objectives Manage Using All Available Strategies • Provide a basic understanding of how to use IPM Principles to reduce pesticide use Cultural Least Toxic in the home and garden. Physical Biological • Reduce pesticide use by managing using Chemical Most Toxic all available strategies – Cultural – Use a least hazardous approach, that will – Physical also enact effective control – Biological – Chemical Cultural Control  Prevention! Plant Selection: Resistant Plants R. davidsonianum Adult Root Weevil Damage to Leaves • Altering your garden or gardening practices to reduce pest populations or injury • Reduce plant stress through proper Root Weevils horticultural practice • Three Components – Plant Selection – Plant Installation List of Rhododendrons Resistant to Root Weevils can be found at: – Plant Maintenance Resistant varieties Information on Managing Root Weevils in the Pacific Northwest: 2
  3. 3. 2/15/2009 Plant Selection: Companion planting Plant Installation • Pests and the Plants that Repel Them • Improper planting often results in stressedFlea beetle Catnip, marigold, nasturtium, peppermint, rue, spearmint, plants. southernwood, tansy • Compacted soils are often a particularJapanese beetle Catnip, chives, garlic, nasturtium, odorless marigold, tansy, white geranium problem on home sites.Rabbit Garlic, marigold, onionSlugs and Snails Fennel, garlic, rosemarySpider mite Coriander, dill Planting container plants Root Preparation Prior to Planting • Thoroughly preparing• Container plants with the roots prior to circling roots or that planting on root- are root-bound should bound pots usually have these problems improves growth corrected prior to immediately as well planting. as plant survival Planting container plants Cultural Control: Plant Maintenance • Size of planting hole • Water for deep, spread roots • Depth of planting • Fertilizing • Finish by watering the – Too much fertilizer can increase insect pest plant in well problems as much as too little fertilizer. • Time of planting • Mulching / Groundcovers – Can reduce weed problems – Avoid bringing new weeds to the garden in manure, straw • Remove and properly dispose of garden debris 3
  4. 4. 2/15/2009 Disease Management: Sanitation Physical/Mechanical Control • Clean up Debris • Use of physical barriers, machines or objects to prevent an infestation (preventative), or kill the pest (remedial) – Horticultural fabrics to cover plants (preventative) – Flyswatter (remedial) Physical Control of Weeds Weed Management• A sharp hoe and lots o’ diligence • Weeds are easier to kill when they are very• Mulch! small – “white thread” to 2-3 true leaves.• Cover crops • Mechanical weeding is more effective during warm, dry, windy weather. Plants can re-root in• Crop rotation cool wet weather. et eather• Whenever possible prevent weeds from • In the Vegetable Garden or Home Orchard- going to seed – Control weeds early in crop growth – Cover crops can reduce subsequent weed pressure Weed Management Physical Control: Sticky barrier• Weeds are easier to kill when they are very • Can prevent small – “white thread” to 2-3 true leaves. pests from• Mechanical weeding is more effective during climbing and warm, dry, windy weather. Plants can re-root in colonizing tree. cool wet weather. et eather • Can prevent• Control weeds early in crop growth pests from• Cover crops can reduce subsequent weed climbing down pressure tree to pupate in soil 4
  5. 5. 2/15/2009 Physical Control: Collars and Copper Barriers for Molluscs Cages Plant Cage on Radishes Cabbage Maggot Control Brown Garden Snail Tin Collar Cutworm Control Physical Control: Row Covers Handpicking • Covers many plants, or entire rows • Protection for seedlings, or during other vulnerable times lnerable • Light, thermal and air environment will be modified Place insects in soapy water to kill them Water Sprays Pruning Spider Mites Spray plants with water to dislodge aphids. Aphids p Aphids Spider mitesMust be sprayed regularly to prevent recolonization. Tent caterpillars 5
  6. 6. 2/15/2009 Vacuuming Tilling Boxelder Bug Flea Garden symphylan Asian Ladybug Beetle Tilling Physical Control: Bug Zappers Biological Control • Biological control is the use of living organisms —parasites, predators, or pathogens—to maintain pest populations below economically damaging levels, and may be either natural (conservation) or applied (augmentative). (augmentative) Royal Walnut Moth The 3 P’s: sitting on a bug zapper Predators, Parasitoids, Pathogens Beneficial Aspects of Arthropods• Pollinators – bees for cucurbits• Food sources – part of the food chain• Biological control agents for weeds and other insects• E h Enhance soil properties il ti• Aesthetic value 6
  7. 7. 2/15/2009 Parasitoid Wasps Braconid emerging from moth cocoon Ichneumonid Ichneumonid Image Source: AMNH Braconid pupae on tomato hornworm Parasitoid Wasps Parasitized Insects Aphid Mummies Parasitized Cabbage Moth Larvae Ptermomalid WaspEulophid Wasp Parasitized Beetle Larvae Parasitoid Emerging from Aphid MummyAphelenid Wasp Encyrtid Wasp Augmentative Biological Control Conservation Biological Control • Increases the abundance of natural enemies where the habitat • Increase local abundance of predators and has been manipulated (Langellotto and Denno 2004) parasitoids by releasing the biological control • Spatial scale of conservation biological control area influences agents into the garden success (Langellotto and Rosenheim in prep) • Use of biological control agents as you would a chemical pesticide h i l ti id Beetle Banks HedgerowStapling Egg Lacewing Egg CardsCards Eggs Field Margin 7
  8. 8. 2/15/2009Conservation Biological Control Strategies Conservation Biological Control Strategies • Reduce Disturbance • Provide Basic Needs – Reduce Pesticide Use on the Lawn and in the – Food Garden – Water – Leave an area of the garden undisturbed – no – Shelter or low mowing, raking or pruning Insectary Plants for Biological Control• Coreopsis, Parsnip,• Mints• Buckwheat• Yarrow• Sunflowers, Asters, Coneflowers• Lobelia• Goldenrod Chemical Control in IPM Organic and Synthetic • IPM permits integrated use of chemical • Organic: Derived from an pesticides, but also actively seeks to minimize organic source applications – Botanicals (pyrethrum NeemTM, RotenoneTM) • REDUCE – spray when needed, and not – Microbials (Bt sprays) according to schedule g – Naturalytes (SpinosadTM) • REPLACE – use other, less toxic alternatives to pesticides • Synthetic: Manufactured • REDESIGN – correct past landscape design pesticides issues to reduce pest problems Organic Pyrethrin Synthetic Pyrethroid 8
  9. 9. 2/15/2009 Organic Fungicides Organic Pesticides • Azadirachtin- Neem • Horticultural oils • Bt- biological • Copper based • Beauveria- biological • Horticultural oils • Sulfur • Insecticidal soap • Serenade (Bacillus subtilus) • Iron phosphate slugs phosphate- • Kaolin clay • Baking soda (K) • Lime Sulfur This is a peach tree • Pyrethrins grafted with two curl • Rotenone resistant cultivars. Cultivar • Spinosad Q 1-8 on the left and the cultivar Mary Jane (with • Sulfur lots of curl) on the right. 2008 PNW Insect page 389 Materials Allowed for Organic Disease Orange = Biological Management- PNW Disease Synthetic Pesticides Organic PesticidesClass Mode of Range of Notes Class Mode of Range of Notes Action Activity Action ActivityOrganophophates Cholinesterase Broad Potential non-target effects on Microbials – Bt** Stomach Narrow – (Bt-k) Must be ingested in order to be Inhibitor mammals, beneficial insects a poison. caterpillars, (Bt-t) effective. Thus, targets only those concern Paralyzes beetles, (Bt-i) - insects that are feeding on theCarbamates Cholinesterase Broad – Chewing Potential non-target effects on insect gut. Flies protected plant. Inhibitor I hibit Insects I t beneficial i b fi i l insects a concern, t Microbial Mi bi l Overexcites O it Leaf Ch L f Chewers, Low t i it t mammals and L toxicity to l d mammals Derivitives – nervous Thrips, some Gall beneficial insects.Pyrethroids Impacts Ion Broad Low toxicity to mammals, birds. Spinosad** system Makers Channels Toxic to fish. Potential non-target Horticultural Oils** Smothering Effective against Low toxicity and minimal impacts effects on beneficial insects. (block many insects – on non-target insects.Neonicitinoids Impacts Ion Broad – Systemic. Low toxicity to mammals. spiracles) active stages and Channels Homoptera and Potential non-target effects on eggs beetles beneficial insects, especially bees. Insecticidal Soaps** Disrupts cuticle Small, soft-bodies Vertebrates and non-target insects insects and mites generally not impacted. Toxic against beneficial mites. May directly harm plant Organic Pesticides Broad Spectrum / Non-SelectiveClass Mode of Range of Notes • Controls a wide range of pest organisms Action ActivityBotanical Impacts Ion Many insects, but Low toxicity to mammals. Rapid – Organophosphates (a.i. malathion)Insecticides - Channels particularly useful break down in sun. Degradationpyrethrum against limits impact on beneficial insects, – Carbamates (a.i. carbaryl, methomyl) caterpillars, sawfly but may require repeat application. larvae, larvae leaf – Pyrethroids ( y (a.i. cyfluthrin, fenpropathrin) y p p ) beetles, leafhoppers – Neonicotinoids (a.i. imidacloprid)Botanical Inhibits Effective against a Low toxicity to mammals. Low riskInsecticides - neem feeding, limited range of to beneficial insects. interferes with insects. molting and egg production Examples of Broad Spectrum Information for Tables Taken From: Whitney Cranshaw. Classes of Pesticides Used in Landscape/Nursery Insecticides Pest Management. In Chapter 9 of Tactics and Tools for IPM. 9
  10. 10. 2/15/2009 Narrow Spectrum / Selective Organic Herbicides• Controls a narrow range of pest organisms • Acetic acid (vinegar-based) • Clove/citric acid based – Insect Growth Regulators (IntrepidTM), • Herbicidal Soap – Bacillus thuringiensis (B.t.), Bt-k (DipelTM) and – Contact Bt-t (NovodorTM) – Non-selective – Do not translocate – OK for annuals – Perennials- hmmm Colorado potato beetle • Corn gluten Leptinotarsa decemlineata. – Pre-emergent Bt-t toxin is effective against – Not effective – Good N fertilizer This pest of potatoes, tomatoes and other solanaceous crops Minimizing the Negative Effects of Chemical Control Chemical Control• Although chemical control should be the • Avoid applying pesticides on a windy day. last tactic considered, it may be the only way to quickly and effectively keep a • Choose narrow over broad spectrum particular pest in check. insecticides.• Used correctly pesticides are indispensable correctly, • Spot treat, rather than broadcast a p tools of an IPM program pesticide.• Incorrect use of pesticides can lead to: • Always read the label, follow directions and do not apply more than is recommended. – pest resistance to the pesticide – outbreaks of secondary pests • Wear protective clothing and eyewear. – adverse effects on nontarget organisms • Dispose of unwanted pesticides and empty – direct hazards to the user containers properly. Summary • There is no true silver bullet – Pesticides come with pros and cons – Alternatives to pesticides come with pros and cons • Conservation biological control is the best, long term pest management strategy available to home gardeners 10