- - AGRICULTURE CORE CURRICULUM - - (CLF7000) Advanced Core Cluster: PLANT AND SOIL SCIENCE (CLF7350) Unit Title: PLANT PATHOGENS AND PESTS ____________________________________________________________________________ (CLF7355) Topic: SAFE AND Time Taught in Year(s) EFFECTIVE USE OF 3 hours 3 and 4 CHEMICAL PESTICIDES ____________________________________________________________________________ Topic Objectives: Upon completion of this lesson the student will be able to: Learning Outcome #: (F-22) - Use approved safety measures when using chemical pesticides. (F-22) - Describe the four toxicity categories of pesticides and the safety regulations governing them. Special Materials and Equipment: Five chemical labels. References: Agrios. PLANT PATHOLOGY. pg 126-143. Hartman, H. PLANT SCIENCE. pg 237-265. Marer, P. (1988). THE SAFE AND EFFECTIVE USE OF PESTICIDES. pg 1,73-80,133-137,149-174,175-232, 247-270. Evaluation: Quiz by instructor TOPIC PRESENTATION: THE SAFE AND EFFECTIVE USE OF CHEMICAL PESTICIDES INTRODUCTION A. The selection, use, and handling of pesticides is a complex topic. B. Hundreds of chemicals are registered for this use and these act in many different ways. C. Some pesticides are more toxic than others and so present more risk to humans and the environment. D. Regulations establish the format for labels and dictate what information they must contain. Labels are legal documents. E. Many pesticides are hazardous and may harm people or the environment if not properly used. F. The pesticide applicator is the key to preventing pesticide accidents. G. Pesticides must be used effectively as well as safely. THE SAFE AND EFFECTIVE USE OF CHEMICAL PESTICIDES. A. Pesticides are defined as any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any insect, rodent, nematodes, fungi, or weeds or any other form of life declared to be a pest, and any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant. B. Toxicity is the capacity of a chemical to cause injury (sometimes called potency). C. Pesticides must be toxic in order to kill pests. D. They can be a hazard because they have the potential for causing harm to living organisms other than pests. E. One way of determining the relative ACUTE toxicity of a pesticide is by determining the amount (lethal dose) that will kill 50% of a test population of animals. 1. This is referred to as the LD50 (lethal dose that kills 50% of test population). 2. The LD50 is expressed as the milligrams (mg) of pesticide per (kg) of body weight of test animals (mg/kg). 3. Pesticides that are more toxic (have lower LD50) usually present higher hazards, or risks of injury, to people and their environment. 4. Special care must be taken when handling all pesticides, although those with lower LD50 may require additional safety precautions. 5. Pesticides that can pass through the skin readily may be more hazardous than those that don't. A pesticide that is highly caustic is more dangerous to the eyes than one that is not caustic. 6. Routes of entry into the body include the mouth, skin, eyes, and lungs. F. Pesticides are grouped into four categories by the Environmental Protection Agency (EPA). 1. They are grouped according th their toxicity or potential for causing acute injury to people: CATEGORY SIGNAL WORD AMOUNT TO KILL A PERSON TOXICITY I. Danger-poison (with 1 drop to 1 teaspoon Highly Toxic skull and crossbones) LD50 D-50 mg/kg II. Warning 1 teaspoon to 1 ounce Moderately LD50 30-500 mg/kg Toxic III. Caution over 1 ounce Slightly LD50 500 - 5000 mg/kg Toxic IV. Caution (LD50 greater over 1 ounce Slightly than 5,000 mg/kg) Toxic 2. The signal words listed on the chart above will appear on the label of pesticides of each toxicity category. 3. All labels must also state "Keep out of Reach of Children." G. Regulations establish the format for pesticides labels and prescribe what information they must contain. 1. Every pesticide must be registered with EPA and CDFA before it can be sold or used in California. 2. Labels are legal documents that contain important information for the user such as hazards, pests controlled, sites where it can be used, first aid information, rates to use, how to dilute specific applications instructions, protective clothing requirements, worker reentry requirements, days before harvest, etc. 3. The label is a tool; learn to use it properly. 4. You must obtain, read, and understand all of the information on a label and referenced documents before making a pesticide application. H. There are several possible side effects associated with pesticide use. 1. Beneficial species may be reduced. a. This is one of the most serious side effects. b. Without aid of beneficial species even the best use of chemicals would not be enough. Beneficial species can reduce the use of chemicals and help us prevent some of the problems associated with chemicals such as the development of resistance. 2. Drift is a potential problem when dusts and sprays are used. a. The severity of the problem depends on the physical size of the dust particles or spray droplets, how applied, pressure, volume used, and weather conditions. b. Drift can damage adjacent crops, cause illegal residues on food crops or forage,create a danger human health, and cause environmental pollution. 3. Wildlife may be harmed accidentally by pesticide use. 4. Honeybees and other pollinating insects can be lost. a. Timing of application is extremely important to avoid those losses. b. We would not have fruit without pollinators. 5. Environmental pollution is a continuous problem. a. Our air, water, and soil can become contaminated. b. The extent of ground water contamination is just beginning to be realized. 6. Residues remain on treated surfaces for a period of time after pesticides are applied. 7. Pesticide resistance can become a problem when the same or similar pesticides are continually used to control a pest. Weeds may become tolerant to certain herbicides after repeated use. I. Often different pesticides can be used for the same pest. When making the selection we must consider the following: 1. What is the specific pest to be controlled? Identify it. 2. Can the pesticide be legally applied to the target crop or site? 3. Is the pest of economic importance? 4. What are other possible methods of control (cultural, mechanical, or biological)? 5. Where is the pest located? 6. What is the toxicity of the pesticide? (If you have a choice select the one with the lowest toxicity.) 7. Are the beneficials present and will the pesticide harm these beneficials? 8. What are the hazards to the applicator, other workers, the public, and livestock? 9. Is there a potential drift problem? 10. Will the pesticide leave an illegal residue? (Pesticides must usually leave a residue to be effective, some last too long for food safety, worker re-entry, etc.) J. Applying pesticides requires many special skills and tremendous responsibility. 1. The Environmental Protection Agency requires that each state have a certification and licensing procedure and program for persons using restricted use pesticides. a. In California, anyone handling, mixing or applying any pesticide must receive specific training about each pesticide being used on a yearly basis. Employers must maintain written records of training subject to inspection by the agriculture commissioner. b. Persons making pest management recommendations in California must possess a B.S. degree in a biological science, 2nd pass state exams, then take a minimum of 40 hours of continuing education classes every 2 years. c. In California and the rest of U.S., anyone applying restricted use pesticides must be certified usually by state department of agriculture; CDFA in California. This requires testing for commercial applicators in California. Private applicators (growers) in California must obtain a permit from county ag commissioners and must demonstrate competence in handling the restricted pesticide. In California, commercial applicators must take 20 hours of continuing education every 2 years to renew certificate or license. 2. Before a person is allowed to make pesticide recommendations, buy, use, or supervise others using these chemicals, state exams must be passed. 3. Certificates and licenses usually must be renewed every two years. 4. In many states several hours of continuing education must be completed before these certificates or licenses are renewed. 5. Your local agricultural commissioner can give you information and help on applying for these certificates and licenses. ___________________________________________________________ ACTIVITY: Supply students with 5 or more chemical labels (preferably on the containers as they are purchased). Have each student complete the following chart using the provided chemicals: ___________________________________________________________ ____________________________________________________________________________ Signal | | | Active | Inert |Warnings Brand | Name |Intended Use | Ingredient |Ingredients | | | | | | __________|____________|_____________|____________|____________|____________ Example: | | | | | | | | | | Ortho Bug |Snail & Bug |Kills snails |3.25% | 96.75% |Caution: Geta |Pellets |& Slugs |Metaldehyde | |don't use | | | | |around pets | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ============================================================================ ____________________________________________________________________________ Common Disease Name Affected Host Class of Organism ____________________________________________________________________________ Example: Using Kocide 101 label (an agricultural fungicide) Leaf Spots Alfalfa Fungus Blossom brown rot Almonds Fungus Shot hole (Coryneum Blight) Apricot Fungus Scab Avocado Fungus Bacterial Blight Beans Bacteria Early Blight Tomatos Fungus Downy Mildew Broccoli Fungus Carrot Blight Carrots Fungus Walnut Blight Walnut Bacteria Powdery Mildew Grapes Fungus ____________________________________________________________________________ ____________________________________________________________________________ K. Following is a list of warnings on the use of pesticide chemicals and suggestions for their proper use.* SUPPLEMENTAL HANDOUT #1 A. Pesticides are poisonous and should always be used with caution. The following suggestions for using and handling pesticides will help minimize the likelihood of injury from exposure to such chemicals to humans, animals, and crops other than the pest species to be destroyed. a. Always read and exactly follow all precautionary directions on container labels before using sprays or dusts. Read all warning and cautions before opening the container. Repeat this process every time you use the pesticide regardless of how often you use it or how familiar you think you are with the directions. Apply materials only in amounts and at times specified. b. Keep sprays and dusts out of reach of children, unauthorized persons, pets, and livestock. Store all pesticides outside the house in a locked cabinet or shed and away from food and feed. c. Always store sprays and dusts in their original labeled containers and keep then tightly closed. Never store them in anything but the original container. d. Never smoke, eat, or chew anything while spraying or dusting. e. Avoid inhaling sprays or dusts. When directed on label, wear protective clothing and a proper respirator. f. Remove contaminated clothing immediately and wash the contaminated skin thoroughly if liquid concentrates are accidently spilled on the skin or clothing. g. Always bathe and change to clean clothing after spraying or dusting If this is not possible, wash hands and face thoroughly and change clothes. Wash clothing after applying pesticides; never reuse before laundering. Launder this clothing separately from the family wash. h. Cover food and water sources when treating around livestock or pet areas. Do not contaminate fishponds, streams, or lakes. i. Always triple rinse liquid containers and dispose of empty containers so that they pose no hazard to humans, animals, valuable plants or wildlife. Never burn pesticide containers, especially aerosol cans. j. Read label directions and follow recommendations to keep residues on edible portions of plants within the limits permitted by law. k. Call a physician or get the patient to a hospital immediately if symptoms of illness occur during or shortly after dusting or spraying. Be sure to take the container or the label of the pesticide used to the physician. l. Do not use the mouth to siphon liquids from containers or to blow out clogged lines, nozzles, etc. m. Do not spray with leaking hoses or connections. n. Do not work in the drift of the spray or dust. o. Confine chemicals to the property being treated and avoid drift by stopping treatment if the weather conditions are not favorable. p. Protect nearby evergreen trees and shrubs from the dormant sprays used on fruit trees. q. Do not use household preparations of pesticides on plants because they contain solvents that can injure plants. * Source: Division of Agricultural Science, University of California. 7/24/90 gfv/sg #%&C