Download Oregon Pesticide Applicator - Right of Way 76: Approved and Verified Answers and more Exams Agronomy in PDF only on Docsity!
way 76 Approved and Verified answers.
Oregon pesticide applicator - Right off
way 76 Approved and Verified answers.
Epinasty - ANSWER-abnormal downward curving growth or movement of a leaf resulting from more rapid growth of cells on the upper rather than on the lower side of the leaf stalk IPM - ANSWER-Integrated Pest Management The management of pest populations below levels that cause economic damage by using a compatible balance of biological, cultural, chemical, genetic, or other control methods. Winter annual - ANSWER-germinates in the late summer or fall, grows through the winter, and blooms and sets seed in the spring, dying by summer Summer Annual - ANSWER-Plants that germinate in the spring or summer and complete their life cycle within one year. Perennials - ANSWER-A flowering plant that live for more than two years with living indefinitely by growing from vegetative plant parts. Reproduction is done through seed (sexual) or vegetative (asexual) making them difficult to control and making it necessary to prevent seedlings from establishing. Classified based on how they resprout: simple or creeping. Biennials - ANSWER-A flowering plant that completes its life cycle in two years. In the first year, they form basal leaves (rosette) and a taproot. In the second year, it flowers, matures and dies. Can be confused for winter annuals since winter annuals live during 2 calendar years and 2 seasons; however, they complete their life cycle within 12 months. Factors affecting herbicide activity - Plant factors - ANSWER-Different foliar wetting. The shape of plant parts affect how spray is retained. Spray retention is key. Locations of growing points changes method of poison delivery. Plants tolerance Directed spray or shielding beneficial plants physically
way 76 Approved and Verified answers.
Factors affecting herbicide activity - How selective herbicides work - ANSWER-Growth habits. Broadleaf perennial weeds have deep, underground root systems while perennial grasses may use rhizomes or stolons and survive chemical and mechanical means. Allowing perennial growth controls root reserve which allows perennial eradication. Annuals have fibrous or tap root systems difficult to control manually and variable chemical success. Weed control factors. Control methods and herbicide use is based on species present. Stages of growth. Annuals are easiest to control at seeding stage. Perennial should not be allowed to establish past seedling else they must be controlled through good storage depletion. Environmental conditions. Herbicide activity is directly proportional to temperature. Dinoseb and MSMA work only at higher temp with 2,4-D having more latitude. Herbicide effectiveness is directly proportional to humidity due to a thinner cuticle and open stoma. precipitation is related to humidity and is an important leaching factor or an herbicide activator. Weed resistance factors Monocotyledons (monocots) - ANSWER-Flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. Grasses. Rushes. Dicotyledon - ANSWER-1. A subdivision of flowering plants whose members possess an embryonic seed leaf made of two halves or cotyledons.
- Herbaceous broad-leafs. Axil - ANSWER-angle between petiole and stem Petiole - ANSWER-The stalk of a leaf, which joins the leaf to a node of the stem. Herbaceous broad-leafs - ANSWER-Die back each winter. Leaves are broad with net-like veins. Usually have a taproot and coarse root system. Growing points at the end of each stem and axil. Often the target on road or rail rights-of-way since they frequently invade grass and bare-ground. Sedges - ANSWER-Perennial plants with triangular, jointless stems and narrow, grasslike leaves. They have spiked inflorescence. Most common in moist environments.
way 76 Approved and Verified answers.
established, become the most difficult to control and may require multi-faceted targeting including mechanical and herbicidal. Creeping root propagation: Canada Thistle Field Bindweed Creeping stolons or rhizomes: Bentgrass Bermuda Grass Creeping rhizomes: Quackgrass Johnson Grass Yellow Nutsedge Other types: Leafy Spurge Simple Perennials - ANSWER-Spread primarily by seed, they can resprout from the taproot. Roots are fleshy and may grow very large. Dandelion Curly Dock Buckhorn Plantain Broadleaf Plantain Dalmation Toadflax Pokeweed Creeping Stolon - ANSWER-Aboveground horizontal stems. Creeping rhizome - ANSWER-Belowground horizontal stems. Give three examples of weeds - ANSWER-Dalmation toadflax, Scotch broom, kochia. Name four ways in which weeds are spread - ANSWER-People, wind, water, animals T/F 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-Broadleaf have netlike leaf veins and growing points at the end of each stem and in each leaf axil. Grass weeds have parallel leaf veins, fibrous root systems, and a single growing point near the soil surface.
way 76 Approved and Verified answers.
Name three summer annual weeds. - ANSWER-Green foxtail, yellow foxtail, puncturevine, Russian thistle, crabgrass, kochia, and common lambsquarters are all summer annuals. IVM - ANSWER-Integrated Vegetation Management Uses preventive, cultural, mechanical, biological, and chemical control measures to control undesirable vegetation and enhance the environment for desirable plants. The basis is to properly identify the weed so you can learn its biology to identify its weaknesses in relation to where it is growing allowing you to determine control methods and evaluate benefits and risks of each. IVM practices - ANSWER-Scouting, making maps, using thresholds, and developing unified programs with few side effects. Scouting - ANSWER-Power line inventory once a year. Some inventories must be done 3 times a year. Suggested times are late spring, midsummer, and early fall. Done on a mile by mile basis. Make note of extensive noxious weeds. Note any significant differences in disturbed areas and soil conditions (slope, texture, poor drainage). Record height of undesired vegetation. Record sensitive areas (streams, home gardens, orchards, schools, high-value, or specialty crops) that require different management strategies. Maintain records for several years to minitor vegetation growth, management practices effectiveness, appearance of new species, and other developments or changes. Reading the landscape - ANSWER-Annuals found in non-bareground managed areas indicate recent disturbance to the site or nutritional depletion that cannot support perennial ground cover. The presence of reed canarygrass, cattails, rushes, and sedges reflects wet, poorly drained areas that may have standing water. St. Johnswort and diffuse knapweed reflect sandy, well-drained soil. Foxtail barley or rabbitfoot clover along the pavement may indicate high salt levels. Mowing and brush cutting encourages sprouting of - ANSWER-Trees, shrubs, and perennials while controlling annuals and biennials. Cultural practices include - ANSWER-burning, flooding, mulching, tillage and planting of competitive desirable vegetation. Allelopathy - ANSWER-The production of chemicals by plants that inhibit the growth of neighboring plants. What is scouting and what information should be recorded? - ANSWER-Scouting is the process for routinely observing the right-of-way for weeds. The types of weeds present
way 76 Approved and Verified answers.
enters the plant through the foliage or roots and is transported to other parts. 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 (mode of action). - ANSWER-Growth regulators change the hormone balance and protein synthesis in plants, thus causing the plant to grow abnormally. What property of 2,4-D makes it dangerous to apply on hot days? - ANSWER-2,4-D has a high volatility. In hot weather it can vaporize and damage surrounding plants. Casoron is in which major mode-of-action group? - ANSWER-Seedling growth inhibitor. Name three active ingredients that are among those most likely to leach into groundwater. - ANSWER-Many correct answers. Tebuthiuron, picloram, bromacil, etc. When an herbicide kills one species of plant while not affecting another species, it is called: - ANSWER-Selective Name four factors that might affect herbicide selectivity. - ANSWER-Application rate, formulation, timing, and placement. Roundup (glyphosate) is in which major mode-of-action group? - ANSWER-Amino acid synthesis inhibitors. Modes-of-action - ANSWER-Growth regulators Amino acid synthesis inhibitors Seedling growth inhibitors Photosynthesis inhibitors Cell membrane disruptors Plant growth regulators Growth regulators - ANSWER-Disrupt the hormone balance and protein synthesis in plants, causing growth abnormalities. Growth regulators select for broadleaf weeds in grass stands. Injury can occur to grasses if applied at high rates. Translocate to growing points and injury symptoms occur in new plant growth. Foliage based but some root absorption may occur. Amino acid synthesis inhibitors - ANSWER-Prevent the production of amino acids that form proteins fundamental to normal plant development. Can be either foliage or soil applied. Symptoms of activity may include stunting, chlorosis (yellowing), or purpling of leaves.
way 76 Approved and Verified answers.
Seedling growth inhibitors - ANSWER-Interfere with the new plant growth, stopping normal seedling root or shoot development. Must be applied to the soil to act on emerging seedlings. Photosynthesis inhibitors - ANSWER-Interfere with photosynthesis resulting in the build- up of toxic products. The triazine, urea, and uracil herbicides are primarily root absorbed and translocated to leaves with water. Symptoms usually 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 chlorosis or necrosis of leaf tissue. Cell membrane disruptors - ANSWER-Destroy plant tissue by disrutping cell membranes. These products are contact herbicides having little or no mobility in the plant and must be applied postemergence. They are excellent for rapid foliage burn- down and control of annual weeds. Symptoms include rapid wilting and necrosis (browning) of plant tissue. Plant growth regulators - ANSWER-Pesticides that suppress plant growth, thus reducing mowing and maintenance requirements. They often reduce sucker and sprout growth in perennials and can prevent seed head formation in grasses. Treated plants look stunted and compact in growth. Preplant - ANSWER-Application made before seeding or transplanting. Applied to the soil and incorporated into the soil through mechanical means, rainfall, or overhead irrigation. Preemergence - ANSWER-Treatment made prior to emergence of the weed or crop and commonly applied to the soil. If weeds are present, you may need to mix the preemergent herbicide with a postemergence foliar herbicide. Preemergent herbicides must be incorporated into the soil. Postemergence - ANSWER-Any treatment made after the emergence of a weed. This treatment usually is a foliar application. Young weeds are controlled more easily than established weeds. What are the two major factors influencing herbicide efficacy. - ANSWER-Availability of an herbicide affected by environmental influences and the plants absorption and translocation of the herbicide affected by the growth stage of the plant and environmental influences. Environmental influences on herbicide activity - ANSWER-Absorption and soil texture are examples of soil factors. Temperature, precipitation, and humidity are examples of climatic factors.
