Pest Management Why is pest management important in the horticulture industry?
Key Questions • What are the five major categories of pests? • Explain best management practices while maintaining environmental integrity. • What is complete and incomplete metamorphosis of insects? • What is the difference between selective and nonselective herbicides? • What are alternative pest control techniques? • What safety precautions are necessary when handling, applying, and storing chemicals? • What is integrated pest management (IPM)?
What are the five major categories of pests? • Pest • Anything that causes injury or loss to a plant • Can damage plants by: making them less productive, affecting reproduction, or destroying them • Host • plant that provides a pest with food • Five major categories 1. Insects 2. Nematodes 3. Weeds 4. Diseases 5. Rodents and other animals
1. Insects • Three distinct body parts • Head, thorax, abdomen • Three pairs of legs • Either one, two or no pairs of wings
Insect-related pests • Spiders and mites • Four pairs of legs and two body sections • Centipedes • One pair of legs/body section • Millipedes • Two pairs of legs/body section • Sowbugs and pillbugs • Seven pairs of legs • Snails, crayfish, and slugs
Insect body • Cylindrical and segmented • Made up of: • External skeleton (body wall) • Internal muscles and organs • Respiratory system with openings in sides of body wall • Nervous system consisting of brain, nerve cord, sensory nerves in the antennae, eyes, mouth, and feet
Insect feeding • Depends on structure of mouth: 1. Chewing- mandibles (grubs, beetles, caterpillars) 2. Piercing and sucking- elongated beaks with an injecting organ (aphids, leafhoppers, mosquitoes)
Insect feeding • Variations include: 3. Siphoning (moths and butterflies) 4. Rasping (thrips)
Beneficial insects • Help plants grow by • Improving the soil • Pollinating plants • Destroying harmful insect pests • Examples • Lady beetle, praying mantis, common green lacewing
Insect Control Program • Identify insect and population/monitor. • Determine potential for damage/economic threshold. • Assess potential environmental issues/hazards. • Decide on integrated control measures or tactics/action threshold. • Use control measures. • Evaluate the results. • Assess resulting environmental issues/problems.
2. Nematodes • Appendageless, nonsegmented, worm-like invertebrates that have a body cavity and complete digestive tract, including mouth, alimentary canal, and anus • Do not have a specialized respiratory or circulatory system • Have a well-developed nervous system, an excretory system, and a set of longitudinal muscles
Feed by penetrating root cells with a hollow stylet mouth structure and injecting enzymes into cells • Enzymes digest cellular contents, which are ingested by nematodes. • Resulting wounds allow entry of fungi and bacteria.
Symptoms of nematodes • May mimic problems such as: • Low or unbalanced fertility • Sun scald or frost damage • Poor drainage • Drought damage • Insect or mite damage • Wilt or root-rot fungi • Herbicide damage
Preventive measures for nematodes • Using disease-free planting materials • Proper site selection • Using cultural practices to ensure good growth
Three categories of nematodes • Ecto-parasitic • attached outside of host • Endo-parasitic • Feed externally on and internally within roots • Semi-endo-parasitic • Partially embedded
3. Weeds • Plants growing out of place or an unwanted plant • Grow and persist • May detract from the color, texture, or density of the desired plant
Problems with weeds • Detract from appearance • Compete for light • Compete for water • Compete for nutrients • Compete for space
Classifications of weeds • Grasses- monocots • Broadleaves- dicots • Other- sedges, rushes, wild onions, wild garlic • Categories include • Annuals (winter and summer) • Biennials • Perennials
Other types of weeds • Moss • Tangled green mats composed of a branched, thread-like growth over the soil surface • Algae • Group of small, primitive, filamentous, green plants that manufacture their own food
4. Diseases • Abnormal conditions in plants that interfere with their normal appearance, growth, structure, or function • Groups of diseases • Abiotic- noninfectious disorders • Biotic- caused by parasites or pathogens that are infectious and transmissible
Favorable conditions • Susceptible host • Causal agent • Favorable environment • Methods of control • Increasing the host’s resistance • Altering the environment to hinder the pathogen • Keeping the pathogen away from susceptible hosts
Symptoms of disease • Rotting plant parts, particularly the fruit • Leaves turning yellow or having an unnatural color • Plants wilting • Plants having twisted leaves or stems • Buds, flowers, or fruit not developing or falling off • Dead plants
Two major types of disease • Environmental- caused by elements in plant’s environment that are not right for the plant • Nutrient deficiencies • Damage to plant parts • Chemical injuries • Pollution injuries • Weather-related injuries • Naturally occurring genetic abnormalities
Parasitic- caused by microorganisms • Fungi- small one-celled, usually filamentous, spore-bearing. Fungi grow on or in plants and cause plant mildew, plant rusts, and plant smuts. Spread by wind, water, insects, and in other ways. • Bacteria- small, one-celled organisms with a primitive nucleus • Viruses- infective living agents of microorganisms that do not have an organized nucleus. Spread by insects, equipment, and vegetative propagation.
5. Rodents and Other Animals • Animals pests that eat leaves, stems, fruit, and roots of plants • Preventing and controlling animal pests involves destroying habitat and getting rid of the animals
Explain best management practices while maintaining environmental integrity. • (BMP’s) Best Management Practices • Those practices that combine scientific research with practical knowledge to optimize yields and increase crop quality while maintaining environmental integrity.
Best management practices used in horticulture situations: • Management of surface and subsurface water runoff • Erosion control • Cultural control of pests • Soil testing • Timing and placement of fertilizers • Controlled release fertilizers • Irrigation management • Biological control of pests • Pesticide selection • Correct pesticide use
Describe complete and incomplete metamorphosis of insects • Metamorphosis- development of an insect • Complete metamorphosis- insect who life cycle goes through four distinct stages: • Egg • Larvae- looks nothing like the adult • Pupae- transformation stage • Adult Examples: caterpillars to moths or butterflies, grubs to beetles, maggots to flies • Instars- insect growth by shedding of external skeleton in 4-5 stages
Incomplete metamorphosis • Life cycle changes from egg through nymph to adult. • Nymph looks similar to adult, only differing in size and color • Examples: aphids, leafhoppers, mole crickets, and chinch bugs According to Figure 8-6, what are the differences in complete and incomplete metamorphosis?
What is the difference between selective and nonselective herbicides? • Selective herbicides • Control a limited number of plant species • Nonselective herbicides • Destroy all vegetation Name at least one trade name of each type of herbicide.
What are alternative pest control techniques? Pests are controlled in the following ways: • Cultural practices • Biological methods • Mechanical methods • Chemical methods • Genetic methods
Cultural Pest Control • Uses management techniques to control pests • Includes • Primary • Maintenance programs, Sanitation, Resistant varieties • Secondary • Mowing, irrigation, fertilization, pruning, aerification, mulching, etc. During evaluation ask: 1. What is wrong? 2. What is the source of the problem? 3. What should be done about it?
Biological Pest Control • Uses living organisms that are predators to control pests • Examples • Lady bugs control a range of insect pests • Toad frogs eat insects • Bacterium Bacillus thuringinensis when released in fields attack and kill various species of worms
Mechanical Pest Control • Uses tools or equipment for control • Plowing- destroys some pests, particularly weeds • Mowing- cuts off weeds • Mulching- covering the ground with a layer of plastic, sawdust or other material prevents weed growth How have we mechanically controlled weeds in the greenhouse?
Chemical Pest Control • Uses a pesticide, which is a chemical to control pests • Chemicals are often mixed with a surfactant, which is a material to help disperse, spread, wet or emulsify a pesticide formulation
Types of Chemical Pesticides • Insecticide • Controls insects • Material that does the killing is called the active ingredient • Can be in form of dusts, granules, powders, or solutions • Classified by how they get into insect’s body • Stomach poisons- eaten, work on chewing insects • Contact poisons- absorbed thru skin, must contact • Systemic poisons- inside plant, applied to soil or leaves and taken up into plant, insect poisoned when it bites into plant • Fumigants- gas form, enters insect thru respiratory system, must be used in closed places
Nematicide- controls nematodes • Herbacide- control weeds • Classified by • Type of action • Chemical composition • Method of application • Species of plants affected • Examples: • Selective- control limited # of weeds • Nonselective- kills all vegetation • Contact- kills only portions of plant it contacts • Systemic- absorbed into plant’s vascular and root system and destroys entire plant
Methods of Herbicide application • Preplant- applied before planting • Preemergence- applied after planting but before crop emergence • Postemergence- applied after crop emergence • Performance of herbicides depends on: • Temperature • Rainfall • Humidity • Maturity of crop and weeds • Soil characteristics • Chemical concentration
Fungicide- controls disease caused by fungi. The best fungicides are systematic. • Bactericides (germicides)- controls bacteria
Genetic Pest Control • Utilizes biotechnology by gene transfer or genetic manipulation to make plants resistant to specific pests • Biotechnology- mgmt of biological systems for the benefit of humanity • Organismic biotechnology- deals with intact or complete organisms • Molecular biotechnology- involves changing the structure and parts of cells • Transgenic organism- carries a foreign gene that was inserted by laboratory techniques in all its cells
What safety precautions are necessary when handling, applying, and storing chemicals? • Application of pesticides can be dangerous. They may: • Injure people • Injure animals • Pollute the environment • Contaminate water and food
Safety guidelines to follow are: • Use only approved pesticides. • Read the label before application. • Use the pesticide with lowest toxicity. • Use the right equipment. • Mix according to the directions on the pesticide label. • Apply evenly. • Avoid vapor damage. • Clean up. • Store properly. • Know the correct emergency measures.
Techniques for storing pesticides safely: • Storage area should be located where cleanup materials are close at hand. • Keep pesticides in original containers with labels in place. • Never store pesticides near food, medicine, or cleaning supplies. • Do not store flammable materials with pesticides. • Organize materials to be accessible and visible. • Mark each container with the date or purchase. • Routinely check containers for damage or leaks • Dispose of unwanted or outdated materials and containers according to label recommendations.
What is integrated pest management (IPM)? • IPM- Pest mgmt strategy that uses a combination of BMPs to reduce pest damage with the least disruption to the environment • Goal • Keep pest populations below economic or aesthetic injury level
Ecologically based strategy that relies on the following factors to control pests: • Weather • Pest diseases • Predators • Parasites
Phase I of IPM • involves pest ID, monitoring, and action thresholds • Action threshold- predetermined level at which pest control is needed
Phase II of IPM • Involves evaluating all possible control measures • Control options may include: • Chemical • Biological • Mechanical
The basic elements of an IPM program include: • People- system devisors and pest managers • Knowledge and info needed to devise the system and make sound decisions • Program for monitoring the ecosystem elements • Pest densities at which control methods are put into action • Techniques used to manipulate pest populations • Agents and materials
Scouting • Monitoring plants regularly to determine current levels of pest activity • Scouts check: • To identify the presence of a pest • The stage of development • Amount of damage done
Environment and IPM • IPM incorporates the changing or amending of any or all parts of the plant ecosystem to lower pest populations • Ecosystem includes • Biotic factors- living plants and animals • Abiotic factors- soil and water