Download Oregon Right of Way Pesticide 177 A+: Weed Control and Management and more Exams Agricultural economics in PDF only on Docsity!
GRADED 2024-2025.
Oregon right of way pesticide 177 A+
GRADED 2024-2025.
Annual weeds - ANSWER-plants complete their life cycle in less than 1 calendar year summer annual - ANSWER-plants germinate (sprout from seed) in the spring or summer. They grow, flower, set seed, and die before winter. The seeds lie dormant in the soil until the next spring or several springs later, when the cycle repeats itself. Winter Annual Weeds - ANSWER-plants germinate in the late summer to early winter. They overwinter in a vegetative stage. In the spring or early summer, they flower, set seed, mature, and die, but live for less than 1 full year. The seeds lie dormant in the soil during the summer. biennial weed - ANSWER-plants complete their life cycle within 2 years. In the first year, the plant forms basal leaves (rosette) and a taproot. The second year, the plant flowers, matures, and dies. There are no (answer) grasses or sedges. Sometimes people confuse these with winter annuals. Winter annuals normally live during 2 calendar years and during 2 seasons, but they complete their life cycle in less than 12 months. Herbaceous broadleaves - ANSWER-Die back to the ground each winter. Seedlings have two cotyledons (first leaves) and therefore are called dicotyledons. Their leaves are broad with netlike veins. They usually have a taproot and a relatively coarse root system. They have growing points (buds) at the end of each stem and in each leaf axil. These plants often are the target pest plants on road or rail rights-of way since they frequently invade grass sites and bare-ground areas. Grasses - ANSWER-Seedlings have only one leaf when they emerge from the ground and, therefore, are called monocotyledons. Their leaves generally are narrow and have parallel veins. Most have fibrous root systems. The growing point on seedlings are located below the soil surface. It gradually moves up to the soil surface as the plant grows and matures. Perennial weeds - ANSWER-They live more than 2 years, and some may live almost indefinitely, resprouting from vegetative plant parts. Most reproduce by seed (sexually), and many spread vegetatively (asexually) as well. Because of these persistent, resprouting roots, rhizomes, stolons, tubers, and plant fragments, these plants are difficult to control. To prevent problems with these weeds, do not let the seedlings become established. They are classified according to how they resprout: simple or creeping
GRADED 2024-2025.
Sedges - ANSWER-perennial plants with triangular, jointless stems and narrow, grasslike leaves. Rushes - ANSWER-monocotyledonous, grasslike plants that are common in marshy or wet areas. They have cylindrical stems that often are hollow, and they grow in dense clumps. Woody Plants - ANSWER-Woody plants form wood and do not die back during the winter. They include brush, shrubs, and trees. These plants are broadleaves with two seed leaves and a coarse root system. Integrated Vegetation Management - ANSWER-Integrated Vegetation Management (IVM) stresses the control of undesirable vegetation and enhances the environment for desirable plants. Seldom does a single control method give the desired results, especially long-term. To achieve environmentally and economically sound results, most managers design an integrated approach using preventive, cultural, mechanical, biological, and chemical control measures. Scouting - ANSWER-Scouting is the routine observation of the right-of-way to record pertinent information on desired and undesired species. Thresholds - ANSWER-Thresholds are levels of infestation at which control practices are justified. Mechanical control - ANSWER-Mechanical techniques are the oldest methods of vegetation control. They include hand-pulling, blading, grubbing, and mowing. Cultural control - ANSWER-can include burning, flooding, mulching, tillage, and planting of competitive desirable vegetation. Biological control - ANSWER-uses living organisms (insects, animals, or pathogens) to control undesirable vegetation. Chemical control - ANSWER-include the application of herbicides and plant growth regulators, both of which are considered to be pesticides. Contact herbicides - ANSWER-Are applied directly to plant foliage and kill only plant parts they contact directly. They do not move (translocate) throughout a plant. They generally disrupt cell membranes. Activity often is very quick, with visible damage occurring in a few hours. Translocated (systemic) herbicides - ANSWER-Herbicides are absorbed through the foliage, stem, shoots, or roots and move throughout plants. Generally, if absorbed from the soil by roots, these herbicides move with water transported to the stem and leaves.
GRADED 2024-2025.
What is the application of growth regulators? - ANSWER-postemergence Lipid inhibitors. - ANSWER-These prevent the production of fatty acids that make cell membranes required for new plant growth. They are effective against most annual and perennial grasses; broadleaf plants are tolerant. They translocate through the plants from foliar applications. Symptoms of activity usually are cessation of growth, yellowing (chlorosis), or browning of leaves. Amino acid synthesis inhibitors. - ANSWER-These prevent the production of amino acids that form proteins fundamental to normal plant development. Depending on the product, these chemicals can be either foliage or soil applied. Symptoms of activity may include stunting, yellowing (chlorosis), or purpling of leaves. What amino acid synthesis inhibitors belong to the Sulfonylurea chemical family? - ANSWER-Telar, Escort, Oust, Which amino acid synthesis inhibitors belong to the Imidazolinone chemical family? - ANSWER-Arsenal, Chopper, Stalker, Plateau, Which amino acid synthesis inhibitor cannot be used if there is a danger of rain due to runoff? - ANSWER-Plateau Which amino acid synthesis inhibitors cannot be used if there is a danger of heavy rain due to ground water contamination? - ANSWER-Plateau, Arsenal, Chopper, Stalker, Oust Which amino acid synthesis inhibitors cannot be used in saturated or frozen soil? - ANSWER-Telar,Arsenal, Chopper, Stalker Which amino acid synthesis inhibitor is an amino acid derivative? - ANSWER- Glyphosate Which Amino acid synthesis inhibitors are nonselective? - ANSWER-Oust, Finale, glyphosate Which Amino acid synthesis inhibitor is a contact pesticide? - ANSWER-Finale Seedling growth inhibitors. - ANSWER-These interfere with new plant growth, stopping normal seedling root or shoot development. They must be applied to the soil to act on emerging weed seedlings. Symptoms may include stunted or swollen roots on emerging seedlings, or seedlings that never emerge.
GRADED 2024-2025.
Seedling growth inhibitors control what two main groups of weeds? - ANSWER-Grasses and broadleaf weeds. Which seedling growth inhibitors belong to the nitrile chemical family? - ANSWER- Casoron, Norosac Which seedling growth inhibitors belong to the Dinitroaniline chemical family? - ANSWER-Treflan, Oryzalin, Surflan, Stomp, Pendulum, Endurance Which seedling growth inhibitor is toxic to fish? - ANSWER-Endurance, Stomp, Pendulum Photosynthesis inhibitors. - ANSWER-These interfere with photosynthesis (conversion of water and carbon dioxide to sugar in the presence of sunlight). The result is a buildup of toxic products. The triazine, urea, and uracil herbicides are primarily root absorbed and translocated to leaves with water; symptoms generally occur first along the leaf margins and tips of older leaves. Nitrile and benzothiadiazole herbicides do not translocate and must be applied postemergence for contact action. Symptoms include yellowing (chlorosis) or death (necrosis) of leaf tissue. Which Photosynthesis inhibitors belong to the Urea chemical family? - ANSWER- Karmex, Diuron, Direx, Spike Which Photosynthesis inhibitors belong to the Uracil chemical family? - ANSWER-Hyvar Which Photosynthesis inhibitors belong to the Triazine chemical family? - ANSWER- Velpar Which Photosynthesis inhibitors control woody plants? - ANSWER-Hyvar, Spike, Velpar Cell membrane disruptors. - ANSWER-These destroy plant tissue by disrupting certain plant cells. These products are contact herbicides having little or no mobility in the plant, and they must be applied postemergence. They are excellent for rapid foliage burn- down and control of annual weeds. Symptoms include rapid wilting and browning (necrosis) of plant tissue. What are some cell membrane disruptor herbicides? - ANSWER-Diquat, Quick Kill, Reward Are cell membrane disruptor herbicides systemic or contact herbicides? - ANSWER- contact common name of cell membrane disruptors? - ANSWER-diquat
GRADED 2024-2025.
Preplant - ANSWER-any application made before seeding or transplanting in landscape plantings. These treatments generally are applied to the soil and incorporated into the soil to prevent weed emergence. Mechanical means, rainfall, or overhead irrigation can be used to incorporate the herbicide into the soil. Preemergence - ANSWER-Treatment made prior to the emergence of the weed or crop and commonly applied to the soil. If weeds are present, you may need to mix these herbicides with a postemergence foliar herbicide. These herbicides also need to be incorporated into the soil Postemergence - ANSWER-Any treatment made after emergence of a weed. This treatment usually is a foliar application. Young weeds are controlled more easily than established weeds. How to prevent herbicide resistance? - ANSWER-Use other methods of weed control along with herbicides. Rotate among herbicide families with different modes of action. Resist the temptation to use higher rates when weed control starts to decline. Kill all the targeted weeds if possible When combining herbicides, use two chemicals with different modes of action. Sand - ANSWER-This soil type is coarse and does not have many charge or binding sites. It has less surface area for the same volume of soil than silt or clay; therefore, fewer adsorptive sites are available. Lower herbicide rates generally are used on these soils. Silt - ANSWER-Intermediate in surface area per given volume of soil. It has more adsorptive sites than sand but many times fewer than clay and organic matter. Medium application rates often are listed on the label. Clay - ANSWER-This soil type is fine and has a large surface area per given volume of soil, resulting in more adsorptive sites than sand or silt. Higher use rates are listed on the label. Organic matter - ANSWER-This soil type has many times more adsorptive sites to tie up both positively and negatively charged herbicides. It acts like a magnet and has more influence on herbicide adsorption than any other soil factor. Climatic factors - ANSWER-These factors, including temperature, humidity, precipitation, and wind, influence weed control and safety to desirable vegetation. Humidity - ANSWER-A foliar-applied herbicide can enter the leaf more readily under conditions of higher humidity because the leaf is more succulent and has a thinner wax
GRADED 2024-2025.
layer and cuticle. Spray droplets remain liquid on the leaf surface with high relative humidity, allowing more time for the chemical to enter the leaf. With low humidity, wax layers and cuticles are thicker, and evaporation is faster. Wind - ANSWER-It can intensify the effects of drought and high temperature stress. Hot, dry winds cause leaf surfaces to thicken and wax layers to harden. These factors make herbicide penetration into leaves more difficult. It also increases drift, reducing the herbicide dose to the target weeds. When to kill annual weeds? - ANSWER-Seedling stage. For best results with postemergence herbicides, control seedlings as soon as possible after emergence because they are easiest to kill at this stage. Vegetative stage. Plants in the vegetative growth stage use most of their energy resources to produce stems, leaves, and roots. Control is still feasible but more difficult than at the seedling stage. Usually this stage requires higher rates of herbicide. Flowering. During this time, most weed energy resources go into seed production. It is most difficult to kill older, annual plants with chemicals. Foliar herbicide applications at this stage may prevent seed production. Maturity. Maturity and seed set complete the life cycle of annuals. Chemical control is not effective or practical at this stage. When to kill biennial plants? - ANSWER-For best results, control biennial weeds as seedlings. Control of the rosette stage is second best. Control decreases as plants mature. When to kill perennial plants? - ANSWER-Must use translocated herbicides.
- Seedling stage most translocated pesticides.
- Budding 2,4-D
- Fall Regrowth Foliar translocated herbicides
- Early Flower Glyphosate
- Full Flower contact only When to kill woody plants? - ANSWER-The best growth stage for control depends on the herbicide and the plant. If you want to kill the entire shrub or tree, the chemical must translocate to the roots, whether applied to foliage or to the basal portion of the plant, injected into the stem, or applied to the soil. Drift - ANSWER-This term refers to pesticide movement through the air to areas not intended for treatment.
GRADED 2024-2025.
Leaching - ANSWER-Herbicides may move through the soil profile with water. Usually is less if the soil dries out ("setting" the herbicide) after the initial amount of moisture is used to move the chemical to the desired depth. Volatilization - ANSWER-A compound is volatile if it changes from a solid or liquid to a gas at ordinary temperatures. Some herbicides are very volatile; others are relatively nonvolatile. As herbicides volatilize, they are lost to the atmosphere as gases. Removal by plants - ANSWER-Plants absorb and subsequently metabolize many herbicides, removing them from the soil. pH - ANSWER-The acidity or alkalinity (pH) of the soil affects persistence and solubility of some herbicides. For example, alkaline conditions enhance the persistence of sulfonylurea and triazine products. Preplant incorporation - ANSWER-The application and incorporation of herbicide prior to planting. It uses tillage equipment or overhead moisture to mix the herbicide with the soil. The herbicide then is available to kill germinating weed seeds. Preemergence application - ANSWER-Puts herbicide directly in or on the soil before weeds or desirable vegetation emerge. It also may be a foliar application to weeds, prior to emergence of desirable vegetation. Postemergence application - ANSWER-Puts the herbicide on plant foliage. At the time of foliar applications, plants should not be under moisture, heat, or other stress. Avoid drift to nearby sensitive vegetation. Broadcast treatment - ANSWER-This application is a uniform treatment of an entire area. It can be made preplant, preemergence, or postemergence. Spot treatments - ANSWER-Applied to a localized or restricted area, usually to control a small weed infestation requiring special attention. Nonselective or residual herbicides sometimes are used on perennial weed infestations to prevent their spread. Band treatment - ANSWER-Usually means treating a strip. This reduces chemical cost because the treatment covers less area than a broadcast application. It may be made preplant, preemergence, or postemergence. It often is used with mechanical controls. Directed sprays - ANSWER-Keeps herbicides off desirable vegetation. Such sprays usually are at or just above the ground line, treating only the lower part of the plant stem or trunk or vegetation at the base of a tree. Basal sprays - ANSWER-Thoroughly wet the lower 18 inches of stems and the exposed roots of target plants, usually trees or brush. Depending on the herbicide and
GRADED 2024-2025.
formulation chosen, you may make treatments anytime during the year on most species. It doesn't matter whether the plants are dormant or actively growing. These treatments allow application during the growing season when you need to treat areas close to susceptible crops (e.g., legumes, grapes). Thin-line treatments - ANSWER-Treatments are a modified basal stem application. Apply undiluted herbicide concentrate in a pencil-thin band around each stem. Cut-stump treatments - ANSWER-Treatments are made to freshly cut stump surfaces so that herbicide moves down into the roots to control resprouting. Cut surfaces begin to dry within minutes of cutting. Frill or hatchet treatments - ANSWER-Methods involve cutting the bark with downward ax cuts around the base of a tree. Spray or squirt the herbicide into the cambium area (growing wood area inside bark) immediately after making the cuts. Tree injection - ANSWER-These tools speed the frill or notch treatment and, when properly used, do a satisfactory job. Soil treatments - ANSWER-These treatments can control woody plants. They require rainfall to move the chemical into the soil as deep as the feeder roots. Therefore, apply them just before or early in the rainy season. These treatments usually persist in the soil for more than 1 year. Effects develop slowly and may not be apparent until the year after treatment. Invert emulsion applications - ANSWER-Applications use a water in-oil mixture to reduce drift. Since the majority of the mixture is an oil, it is quite viscous (thick) and more difficult to apply. Sprayer - ANSWER-The primary function of any _______ is to deliver the proper amount of chemical uniformly over the target area. When selecting a ______, make sure its components are able to withstand the deteriorating effects, if any, of the formulations you use. Also consider durability; cost; and convenience in filling, operating, and cleaning. Hydraulic sprayers - ANSWER-Water is most frequently used as the means of carrying pesticide to the target area with this spraying equipment. The pesticide is mixed with sufficient water to obtain the desired application rate with a specific nozzle and size, nozzle spacing at a specified pressure, and travel speed. The spray mixture flows through the spraying system under pressure and is released through a nozzle onto the target area. Vehicle-mounted sprayers - ANSWER-Low-pressure, sprayers normally are designed to deliver low to moderate volumes at 15 to 100 pounds of pressure per square inch (psi).
GRADED 2024-2025.
Flood flat-fan nozzles - ANSWER-Nozzles produce a wide-angle pattern and function well when broadcasting herbicides; the nozzle spacing should be 60 inches or less. Optimum operating pressures are 10 to 25 psi. Pressure changes on these nozzles affect the angle and width of the spray pattern more than with regular flat-fan nozzles. The width of the spray pattern increases as the pressure increases. Although the discharge can be directed horizontally backward for a uniform pattern or downward for minimum drift potential, the best compromise position is backward at 45 degrees with the soil surface. Hollow-cone nozzles - ANSWER-At pressures of 40 to 100 psi, these nozzles produce many small droplets that penetrate plant canopies and cover both sides of the leaves more effectively than fan nozzles. They also can be used to spray the foliage of individual brush plants. Adjustable-tip nozzles are commonly used on backpack sprayers in rights-of-way. They allow the operator to change the spray from a solid stream to a fine mist and are operated at relatively low pressures. Full-cone nozzles - ANSWER-These nozzles are suitable for foliar sprays in many rights-of-way sites. They give excellent coverage and few fine particles. Directa-spray and Wobbler nozzles - ANSWER-These nozzles produce very coarse spray droplets. The spray solution is discharged through a rotating or oscillating unit as a stream. When the stream hits the air, it is broken into large droplets. These nozzles usually are used to apply 2,4-DP and related products to brush. Variables that determine granular applicator output - ANSWER-Two variables affect the amount of granules applied per unit area: the size of the gate opening and the ground speed of the applicator. The rate that granules flow out of the applicator depends on the size of the gate opening. A larger opening allows more granules to flow (a higher delivery rate). Changing the size of the gate opening significantly increases or decreases the delivery rate The speed at which the granular applicator travels also affects total output per unit area. When travel speed increases, less material is applied per unit area, and when speed is reduced, more material is applied Variables that determine sprayer output - ANSWER-Three variables affect the amount of spray solution applied over a given area: nozzle output, nozzle spacing or spray width, and ground speed of the sprayer. name four ways weeds spread - ANSWER-People, wind, water, and animals True or false: Weeds are more problematic in disturbed soils - ANSWER-true Name three plant characteristics that generally can be used to distinguish herbaceous broadleaf weeds from grassy weeds. - ANSWER-netlike leaf veins and growing points at the end of each stem and in each leaf axil
GRADED 2024-2025.
name three plant characteristics of grasses - ANSWER-parallel leaf veins, fibrous root system, and a single growing point that is located near the soil surface. What is scouting, and what information should be recorded? - ANSWER-Scouting is the process of routinely observing the right-of-way for weeds. The types of weeds present should be recorded on a mile-by-mile basis. Any noxious weeds that might require special control techniques should be recorded. What is a threshold? - ANSWER-A threshold is the level of infestation at which control practices are justified What are some drawbacks of mechanical control? - ANSWER-Hand-operated methods of mechanical control can be labor-intensive, costly, and dangerous. Mowing does not kill the plant roots, so regrowth is possible. What is biological control? - ANSWER-Biological control uses living organisms (insects, animals, or pathogens) to control undesirable vegetation. True or false: Using herbicides interferes with the goals of Integrated Vegetation Management (IVM). - ANSWER-False. Chemicals can be used as part of an overall IVM program. On which type of weeds are contact herbicides most effective? - ANSWER-Annual weeds are more likely to be controlled by contact herbicides. Biennials and perennials may be controlled by contact herbicides if they are sprayed in the seedling stage. Complete coverage is required for best results when applying contact herbicides to any type of weeds. Most herbicides are contact or translocated? - ANSWER-Most herbicides are translocated. How are translocated herbicides able to control weeds that regrow from underground parts such as rhizomes or tubers? - ANSWER-In translocated herbicides, the herbicide enters the plant through the foliage or roots and is transported to other parts of the plant. In contrast, contact herbicides never reach these areas of the plant, and the plant can resprout at a later date. Describe the basic way growth regulators work to kill plants - ANSWER-Growth regulators change the hormone balance and protein synthesis in plants, thus causing the plant to grow abnormally. Roundup (glyphosate) is in which major mode-of-action group? - ANSWER-Amino acid synthesis inhibitors.
GRADED 2024-2025.
What weather conditions are likely to produce particle drift? - ANSWER-Hot and dry conditions can quickly evaporate the water from large pesticide droplets, turning them into much smaller droplets that are more likely to drift. Temperature inversions are particularly dangerous for drift since droplets can remain suspended for a long time. Name three factors that affect herbicide leaching - ANSWER-Strength of adsorption to soil particles, solubility in water, chemical persistence. Why should pesticide spray formulations that go into suspension not be left standing without agitation? - ANSWER-The herbicide could settle out and cake in the bottom of the tank, making cleaning very difficult. What are some important precautions to take when using bare-ground or residual herbicides? - ANSWER-Know the soil type prior to making the application. Do not mix, apply, or clean spray equipment near wells, areas with shallow water tables, or other bodies of water. Understand the influence of rain and irrigation. Do not apply these types of pesticides where the root systems of desirable vegetation may be present or may extend in the future. Do not apply to frozen or saturated ground, and avoid spray drift during application. Use extreme caution when applying pesticides to slopes, and take measures to prevent humans, animals, and equipment from moving treated soil from the area. What is photodegradation? - ANSWER-The breakdown of herbicides when they are exposed to sunlight. What are some other ways pesticides can be degraded or removed from the soil? - ANSWER-Microbial degradation, chemical degradation, adsorption to soil and organic matter, volatilization, removal by plants. How are basal applications made, and when can basal treatments be applied? - ANSWER-Basal applications can be made year-round to the lower 18 inches of the stems and exposed roots (thoroughly wet) to most species of actively growing or dormant plants. What type of application equipment causes the herbicide mixture to flow through the spray system under pressure and to be released through a nozzle onto the target area?
- ANSWER-Hydraulic sprayers. At what pressure do vehicle-mounted sprayers typically run? - ANSWER-Low pressure (15 to 100 psi). What type of sprayer is well suited for treating individual brush plants and for basal and cut-surface applications? - ANSWER-Backpack sprayers.
GRADED 2024-2025.
What type of material should be used for hoses on spray equipment? - ANSWER- Synthetic rubber or plastic hoses that have a burst strength greater than peak operating pressures and that resist oil and solvents that are in pesticides. What type of nozzle patterns work best for rights-of-way weed control? - ANSWER- Regular flat-fan, flood, and cone nozzles are preferred for rights-of-way weed control What are three things that must be determined before every application in order to deliver the proper amount of herbicide to the target area? - ANSWER-Determine and possibly adjust the equipment delivery rate (calibration), determine how much product is necessary for the job, and determine the amount of carrier for the amount of product to be used. What happens to the delivery rate of a pesticide as the rate of travel of the application equipment increases? - ANSWER-The delivery rate decreases. What is a good precaution to take before tank mixing products? - ANSWER-Read the label for precautions and prohibitions, then perform a jar compatibility test. Name the three signal words that might be found on a pesticide label. - ANSWER- Caution, warning, danger. The ingredients that kill the pest are called ___________ ingredients. - ANSWER- Active. Weeds compete with landscape plants and turf for which of the following - ANSWER- nutrients, light, and water
