Credits: 3 (2 lecture hours, 3 lab hours)

Terms Offered: Contact Instructor

Instructor: James H. Westwood

Prerequisites: BIOL 2304 and CHEM 1036


This course provides an introduction to weeds and weed control. Material includes a consideration of plant traits that contribute to weediness, such as growth habit, propagation, and dormancy, and explores the ecology of weeds in natural and managed ecosystems. A large part of the course deals with practical aspects of weed management, including mechanical, biological and chemical approaches. The efficacy and modes of action of the major groups of herbicides are covered, along with discussion of herbicide resistance in crops and weeds. In the laboratory portion of the course, students will gain experience in weed identification and herbicide symptomology. After completing this course, students will be able to make informed decisions about weed management in general and in specific agronomic, horticultural, forestry, and non-crop situations.

Lecture Topics

  • Weed Biology
    • Concepts and definitions of weeds and weediness
    • Importance of weeds
    • Characteristics of successful weeds
    • Life cycles and classifications of weeds
    • Reproduction from vegetative parts
    • Sexual reproduction
    • Dissemination of weed seeds
    • Seed longevity and dormancy
    • Nature of weed/crop competition
    • Allelopathy
    • Parasitic weeds
  • Weed Ecology
    • Origin and evolution of weeds
    • Genetics of weeds
    • Weed biotypes and ecotypes
    • Agroecosystem and weed/crop dynamics
    • Competitive strategies of weeds
    • Invasive weeds
  • Weed Management Principles
    • Weed control objectives: prevention, eradication, control
    • Integrated Weed Management
    • Weed management thresholds
    • Mechanical control
    • Cultural weed control
    • Biological weed control
    • Chemical weed control
    • Concerns about herbicide use: Environment and toxicity
    • Herbicide discovery, development and registration
    • Herbicide uptake, translocation, metabolism, and mode of action
    • Principles of herbicide selectivity
    • Herbicide resistant crops
    • Fate of herbicides in the environment
    • Soil-herbicide interactions
    • Herbicide-resistant crops and weed management
    • Managing herbicide-resistant weeds
    • Designing a weed management program
  • Weed Management in Specific Crops
    • Aquatics
    • Soybeans and grains
    • Forestry
    • Turfgrass
    • Horticultural crops (small fruits, landscape/nursery ornamentals, vegetables)
  • Weed science in an international context
  • Weed science and emerging technologies