Review, Resources, & References
Test Your Knowledge
Review the key points and then test your knowledge of chemical methods by taking a quiz.
Key Points
1. HERBICIDES ARE AN IMPORTANT INVASIVE PLANT MANAGEMENT TOOL
Herbicides can be very efficient and effective in suppressing or killing unwanted plants, particularly when used in combination with other management methods. They should be used judiciously, safely, and in a way that minimizes effects on nontarget resources.
2. AN INTEGRATED PEST MANAGEMENT APPROACH HELPS MINIMIZE RISK
IPM promotes using pesticides judiciously and in combination with other methods in a way that increases effectiveness and minimizes harm.
3. HERBICIDEs are classified to support understanding
Given the considerable number of herbicides available, different ways of classifying herbicides have been developed to distinguish among them. Herbicide classification also provides a means of understanding general similarities among herbicides. A working knowledge of herbicide classification is essential in selecting herbicides, diagnosing herbicide injury symptoms, managing herbicide resistance, and predicting herbicide interactions in the environment.
4. HERBICIDE MODE OF ACTION
All of the interactions between an herbicide and a plant that occur from application to the final effect are referred to as the mode of action. Understanding the mode of action is essential in selecting the proper herbicide, diagnosing herbicide injury symptoms, preventing herbicide resistance problems, and avoiding nontarget environmental impacts.
5. HERBICIDE MECHANISM OF ACTION
The herbicide mechanism of action is the specific biochemical or biophysical process in the plant that is affected by the herbicide. Using herbicides with different mechanisms of action, or combining them with other control methods, can reduce the risk of developing herbicide-resistant populations.
6. HERBICIDES HAVE BENEFITS AND CONSEQUENCES
Herbicides can be an effective tool against undesirable plant species but can have unintended adverse effects. Benefits must be weighed against the potential for exposure and impacts to human health, nontarget organisms, and the environment. Risks are always present with any herbicide use, but misuse of herbicides can increase these risks.
7. GOVERNANCE AND GUIDANCE FOR HERBICIDE USE
The Federal Insecticide, Fungicide, and Rodenticide Act governs registration, distribution, sale, and use of herbicides nationwide. The US Department of Interior Integrated Pest Management Policy (517 DM 1), the USFWS Pest Management Policy and Responsibilities (30 AM 12), and the USFWS Refuge Manual (7 RM 14), provide further guidance for herbicide use on USFWS lands.
8. SEVERAL FACTORS AFFECT HERBICIDE EFFECTIVENESS
The effectiveness of herbicides is a function of several biotic, abiotic, and procedural factors. Understanding these factors can help applicators select safe and effective herbicides for target species and conditions, properly handle herbicides, minimize impacts to nontarget resources, and determine the most effective time, rate, and technique for herbicide application.
9. MONITORING PROVIDES INFORMATION ABOUT EFFECTIVENESS AND IMPACTS
Monitoring activities should be designed to detect changes not only in target species populations, but also in desirable plant species, as well as adverse effects on other nontarget organisms, and soil and water resources.
10. INTEGRATING METHODS INCREASES EFFECTIVENESS AND SUSTAINABILITY
When used alone, herbicides can provide rapid and effective control of target plant populations. Integrating herbicides with other management methods can enhance the effectiveness of each method and is more likely to achieve sustainable, long term solutions.
General
Western Society of Weed Science - Crop Technology Lessons
The Nature Conservancy - Weed Control Methods Handbook
Herbicide Handbook of the Weed Science Society of America (9th Edition)
University of Florida - Training Manual for Aquatic Herbicide Applicators
Fundamentals of Weed Science (1999)
Zimdahl RL. 1999. Fundamentals of Weed Science. Second edition. San Diego (CA): Academic Press. 556 p.
Weed Ecology: Implications for Management (1997)
Radosevich S, Holt J, Ghersa C. 1997. Weed Ecology: Implications for Management. Second edition. New York: John Wiley and Sons, Inc. 589 p.
US Army Corps of Engineers - Noxious and Nuisance Plant Management Information System
Weed Science: Principles and Practices (2002)
Monaco TJ, Ashton FM, Weller SC. 2002. Weed Science: Principles and Practices. Fourth edition. New York: John Wiley and Sons. 672 p.
Policy and Regulations
US Fish and Wildlife Service - Environmental Quality Program - Pesticides
US Environmental Protection Agency - Regulating Pesticide
http://www.epa.gov/pesticides/regulating/index.htm#establishments
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Masters RA, Nissen SJ. 1998. Revegetating leafy spurge (Euphoria esula)-infested rangeland with native tallgrasses. Weed Technology 12(2):381-390.
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Messersmith CG, Adkins SW. 1995. Integrating weed-feeding insects and herbicides for weed control. Weed Technology 9(1):199-208.
Monaco TA, Osmond TM, Dewey SA. 2005. Medusahead control with fall- and spring-applied herbicides on northern Utah foothills. Weed Technology 19(3):653-658.
Monaco TJ, Ashton FM, Weller SC. 2002. Weed Science: Principles and Practices. Fourth edition. New York: John Wiley and Sons. 672 p.
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Paveglio FL, Kilbride KM. 2000. Response of vegetation to control of reed canarygrass in seasonally managed wetlands of southwestern Washington. Wildlife Society Bulletin 28(3):730-740.
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Schreffler AM, Sharpe, WE. 2003. Effects of lime, fertilizer, and herbicide on forest soil and soil solution chemistry, hardwood regeneration, and hardwood growth following shelterwood harvest. Forest Ecology and Management 177(1-3):471-484.
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