Ag 283 Integrated Pest Management Lecture Notes

Ag 283 Integrated Pest Management Lecture Notes

IPM IPM = a comprehensive approach to pest control using combined methods to reduce pest densities to tolerable levels while maintaining a quality environment. IPM = was being practiced long before it was called IPM Crop rotation Strip cropping Changing planting dates Early harvests Trap cropping IPM attempts to achieve two goals 1. Keep pests populations below economic injury level in production crops and below aesthetic injury level in ornamental crops 2. Avoid adverse effects on humans and the environment IPM does not have the goal of eliminating all pests Some weeds help to prevent erosion Species of weeds may prevent others from germinating Excessive application may occur (Stewardship) Creates pressure on pests to adapt (tolerance) Remove natures balance (prey and predators) Pests = are organisms whose populations densities reach levels that compete with the production of food and fibers. Pests of crops include Insects Weeds Nematodes Plant diseases

Rodents Pesticide use increased 2-3 decades ago 1. minimum tillage 2. aesthetics 3. pressures from land owners more recently usage has declined 1. environmental concerns (water sources) 2. insect and weed resistance 3. minimizing inputs 4. residue in foods **Clinton called for the use of IPM on 75% of the nations managed land by the year 2000 Economic Thresholds number of pests per plant or damage to plants at which point control measures should begin prevents pest populations from increasing and causing economic loss Factors that may affect ET value of the crop (aesthetics) cost of control stresses on the crop Current ET do not account for Environmental factors hard to asses the potential impact or hazards hard to asses cost on society Key to successful IPM program Scouting what

growth stage (crop and pest) stage of infestation crop condition weather patterns significance of the problem Scouting: what are we looking for? amount of damage or crop injury measured as percent damage number of pests # per plant # per sweep # per ft of row Field = unit of land that has been treated the same way agronomically (same planting, variety, rotation etc.) Control Methods chemical nonchemical cultural mechanical biological preventive control methods Cultural Control 1. Healthy crop fertility of soil seed selection stand density 2. Field Crops (competition)

Planting dates Rates Row widths 3. Crop rotation Corn / soybean Vegetable rotations 4. Resistant varieties SCN varieties Phytophthora root rot Wheat (hessian fly) Mechanical Control Physically eliminates the pest 1. Hand pulling, hoeing etc. 2. Pruning trees 3. Screens (rodents) Biological Control Using living organisms to reduce pest populations Natural enemies Wasps -- alfalfa weevel Weed control biologically is limited Ethical questions are faced Pros and cons Preventative Controls Helps to prevent the entry (into an area) and spread of pests Inspections and quarantines Plants Animals

Vehicle Regulation on the import of plants and animals Agricultural Horticultural Preventative weed control Spread by seed or plant part Weed free seed (reputable source) Cleaning equipment Mowing Pruning Harvesting Chemical Control Offer an economical and dependable solution Not 100% success rate Factors that may cause a pesticide to fail or be unaffected 1. Wrong type or wrong rate Malathion for Indian mealmoth Grass herbicide for a broadleaf 2. Application when pest is not susceptible treating for ECB during the egg stage 3. Treating in wrong area of plant or animal Foliage spray for root problem 4. Pesticide resistant pest triazine resistant herbicides Proper application methods helps to insure proper control

Pests - insects, animals, weeds, diseases Beneficial insects predators and or parasites to other insects Praying mantis Parasitic wasps Insects that prey on various weeds Woollybear caterpillars lambs ¼ Insects that produce commercial products Honeybees Silkworms Plant pollinators Vegetable and fruit crops Food for animals and humans Medicinal purposes Bee venom (arthritis) Scavengers eating dead O.M. Aesthetic values butterflies, models for jewelry Injurious Insects Damage food, feed crop, ornamental plants ECB, grasshoppers Insects that attack humans and domestic animals Head lice Mosquitoes Attack stored products Termites Grain insects Indianmeal moth Transmit disease Cockroaches

Ants Mosquitoes Insect Identification Exoskeleton Covers outside of the body Hard & protective Molt several times in life Three pairs of legs Three distinct body regions Head antennae, sensory Long antennae grasshoppers, cockroaches Short beetles, leafhoppers Thorax locomotion Legs and wings attached Most have two pairs of wings Abdomen digestive, respiratory and repro Various characteristics Immature no wings do not reproduce Larvae no legs, Immature vs adult stages differ Mouthparts vary on feeding charac. Leafhoppers, aphids mouths can puncture plant tissue Insect development Incomplete vs complete life cycles (control measures) Incomplete Has three life stages

1. Eggs 2. Nymphs (molt) look like adults (smaller) 3. Adults (reproduce) Grasshoppers Cockroaches Termites Leafhoppers Complete has Has four life stages 1. eggs hatch to larvae (molt) 2. pupae (resting stage) 3. adults 4. adults lay eggs beetles butterflies moth mosquitoes bees ants wasps larval stages differ from adult larvae utilize different food usually one damaging stage caterpillars vs moths Insect relatives pests or control pests mites spiderlike 4 pairs of jointed legs small, wingless scavengers O.M.

hard to identify mites in crops predatory mites feed on other mites populations reduce if sprayed ticks large mites with leasthery skin transmit disease spiders 4 pairs of legs, 2 body regions reduce insect pests centipedes many segments each having 1pair legs not pests or predators millipedes O.M. not pests (usually) Weeds Plant growing where it is not wanted, or out of place Trees Shrubs Grasses Sedges Aquatic plants How do they harm crops? (competition) Moisture Nutrients Light Growing space Hinder harvest Transmit disease

Make crops more susceptible to disease Aesthetics (rightaways etc) Weed Identification Most successful program needs proper ID Life cycle reproduction Seedlings easiest to control Annual Complete their lifecycles in one year Summer annuals (warm season) Germinate > vegetative > repro >die Foxtail Crabgrass Pigweed Cocklebur Winter annuals (cool season) Germinate > overwinter> flower >die (summer) Chickweed Henbit Shepardspurse cheat Annuals most weeds are easiest to control reproduce from seed keep seed sources low control as seedlings before they produce seeds

Biennial complete their life cycles in two years year 1 seed germinates > vegetative growth forms rosette year 2 flower and reproduce seeds in summer wild carrot bull thistle common burdock common mullein Biennials reproduce from seed only after seedling susceptible during rosette before first frost 1 st year before bolting in early summer 2 nd year Perennials live for more than 1 year herbaceous = above ground die back & roots overwinter plants sprout from buds on roots woody = above ground stems remain through winter Simple perennials reproduce from seeds have fleshy taproots (overwinter) only spread vegetatively if cut dandelion curly dock plantain

Creeping Perennials reproduce from seed and vegetatively rhizomes underground stolons aboveground tubers, bulbs, budding roots Vegetative parts contain stored food Tubers yellow nutsedge Jerusalem artichoke Bulbs Wild garlic Rhizomes Johnsongrass Sorghum almum Ground ivy Quack grass Budding Roots Field bindweed Canadian thistle Milkweed Hemp dogbane Paralleled veins, longer than wide Annuals, Crabgrass Foxtails Shattercane Grasses

Fall panicum Perennials Johnsongrass Sorghum almum quackgrass similar but not true wild garlic wild onion cattail yellow nutsedge Grasslike plants Broadleaf Plants net veined leaves less elongated than grasses Herbaceous annuals Pigweeds Lambsquarter Velvetleaf Ragweed Biennial broadleaf Bull thistle Wild carrot Herbaceous perennial broadleafs Canadian thistle Hemp dogbane Milkweed Field bidnweed Woody broadleaf Poison ivy Multiflora rose

Plant Diseases Signs things not common to the plant Spores Fungal tissues Symptoms Overdevelopment galls and swellings Underdevelopment stunting lack of color Death of tissue most common leaf spots, rust Determine if problem is localized or systematic Seed rots dig up and examine Stem lesions, fungi Foliar lesions Root rot symptoms similar to nutrient deficiencies Nematodes- check roots and soil sample