PLNT*6140 Biological and Cultural Control of Plant Disease

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This course explores current concepts and approaches to managing plant pathogens and diseases in crops and natural plant communities by measures that have minimal impact on the environment. Topics include naturally-occurring biological control such as suppressive soils and induced host resistance, use of microbial agents and their modes of action, transgenic disease resistance, use of organic soil amendments and mulches to promote microbial diversity and suppress pathogens, and effects of sanitation, crop sequences, tillage, flooding, soil solarization and other cultural practices on microbial communities, including pathogens and on disease epidemics.




Teaching Assistant:


Credit Weight:


Course Level:

  • Graduate

Academic Department (or campus):

Department of Plant Agriculture



Semester Offering:

  • Winter

Class Schedule and Location:

Please consult WebAdvisor for course schedule and location.

Learning outcomes:

By the end of this course, you should be able to:

  1. Explain how alternative practices such as cultural and biological control can reduce pesticide use while still reducing disease development.

  2. Explain the strategies and mechanisms of biological control in depth

  3. Expand upon the ecological concepts that affect pathogen and host interactions as well as interactions between pathogen and bio-control agent

  4. Interpret and constructively discuss current scientific literature regarding host response to stressors, pest invasion and adaptation and integrated management of pests through biological and cultural control practices

  5. Write a thorough literature review based on peer-reviewed literature on a specific topic

  6. Develop a detailed research proposal based on gaps identified in the literature review and the weekly discussions

  7. Lead a discussion group and clarify concepts related to alternative plant disease management to undergraduate students

  8. Deliver a clear, concise presentation to a group of people 

Lecture Content:

  • Plant pathology review and major concepts
  • Plant disease epidemiology
  • Introduction to IPM
  • Introduction to cultural disease management and plant disease management strategies
  • Biological control strategies
  • Modes and mechanisms of biological control
  • The rhizosphere
  • Suppressive soils and the role of organic amendments
  • Resident vs. introduced organisms
  • Role of the pathogen, antagonist and host in biological control
    *Topics may change as the semester progresses
Labs & Seminars:


Seminars: Friday classes will consist of a discussion of peer-reviewed literature on the lecture topic of the week. The discussions will be student-led based on papers chosen by the student (or the instructor if class enrollment exceeds 12 students).

Each graduate student will be required to lead one of the discussion weeks and to answer questions posed by the undergraduate students.



Course Assignments and Tests:

Assessment Description Weight Learning Outcome
Weekly Discussion Weekly, student-led journal discussions will be held every Friday. Articles for discussion will be chosen by the students or the instructor 25% 4, 7, 8
Bi-weekly Quizzes There will be five bi-weekly quizzes given that will cover the lecture material only. The goal of these quizzes is to keep the students up to date on the material and better prepare the class for the mid-term 25% 1, 2, 3
Term Paper A portion of this course will be dedicated to writing a thorough literature review on a relevant topic to the course material. There will be specific deadlines for choosing your topic and some preparatory information to keep you on track with the paper 17.5% 4, 5
Term Paper Presentation You will make a 15 to 20-minute presentation of your term paper to the class during the last two weeks of class.

Please note that this assessment may be folded into the term paper and research proposal if the class size exceeds the time available for class presentations.

7.5% 8
Research Proposal Graduate students will be asked to write a 5-page research proposal based on gaps in research found while conducting the literature review for their term paper 25% 4, 6


Final examination:

There is no final examination for this course.

Course Resources:

Required Resources


Recommended Resources

Biological Control of Microbial Plant Pathogens (Textbook)
   Campbell, R. 1989.

Natural Enemies: An Introduction to Biological Control (Textbook)
   Hajek, A. 2004

Biological Control of Plant Pathogens (Website)

Biological Control of Plant Pathogens
    Pal, K. K. and B. McSpadden Gardener, 2006

The Plant Health Instructor DOI: 10.1094/PHI-A-2006-1117-02.

Additional Resources

CourseLink (Website)
Lectures presented in PowerPoint as well as any additional material can all be found on CourseLink.


Course Policies:

Graduate Student Responsibilities

This course will be taught concurrently with the undergraduate course, PBIO*4070. However, the graduate students will have more responsibility than the undergraduate students. Specifically:

  • Graduate students will be required to lead at least one discussion session and to answer questions that undergraduate students pose during the discussion period to clarify material from the literature
  • Graduate students will be asked to write a 5-page research proposal based on gaps in research found while conducting the literature review for their term paper. 
Dropbox Submissions

Assignments should be submitted electronically via the online Dropbox tool. When submitting your assignments using the Dropbox tool, do not leave the page until your assignment has successfully uploaded. To verify that your submission was complete, you can view the submission history immediately after the upload to see which files uploaded successfully. The system will also email you a receipt. Save this email receipt as proof of submission.

Be sure to keep a back-up copy of all of your assignments in the event that they are lost in transition. In order to avoid any last-minute computer problems, your instructor strongly recommend you save your assignments to a cloud-based file storage (e.g., OneDrive), or send to your email account, so that should something happen to your computer, the assignment could still be submitted on time or re-submitted.

It is your responsibility to submit your assignments on time as specified on the Schedule. Be sure to check the technical requirements and make sure you have the proper computer, that you have a supported browser, and that you have reliable Internet access. Remember that technical difficulty is not an excuse not to turn in your assignment on time. Don’t wait until the last minute as you may get behind in your work.

If, for some reason, you have a technical difficulty when submitting your assignment electronically, please contact your instructor or CourseLink Support.

Grading Policies

All work is expected on the date due.  Late work will be accepted up to five days late with a 5% grade reduction per business day.

If any quizzes or exams must be missed for professional development, religious, or personal reasons, arrangements must be made with the instructor BEFORE the scheduled date of the exam.  Any exams missed due to emergencies or illness may be made up only if appropriate documentation is provided.

All quizzes will be offered through CourseLink and will be available for a set period and will be timed. If separate arrangements need to be made, either due to conflicts or based on registration with SAS, please be sure to make arrangements with your instructor PRIOR to each quiz.

Quizzes missed without an appropriate reason cannot be made up and will be counted as the dropped quiz grade. If more than one quiz is missed due to documented illness, arrangements can be made to ensure the student is not penalized.



Other Course Information:

University Policies

Academic Consideration

When you find yourself unable to meet an in-course requirement because of illness or compassionate reasons, please advise the course instructor in writing, with your name, id#, and e-mail contact. See the academic calendar for information on regulations and procedures for Academic Consideration:

Academic Misconduct

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University of Guelph students have the responsibility of abiding by the University's policy on academic misconduct regardless of their location of study; faculty, staff and students have the responsibility of supporting an environment that discourages misconduct. Students need to remain aware that instructors have access to and the right to use electronic and other means of detection. Please note: Whether or not a student intended to commit academic misconduct is not relevant for a finding of guilt. Hurried or careless submission of assignments does not excuse students from responsibility for verifying the academic integrity of their work before submitting it. Students who are in any doubt as to whether an action on their part could be construed as an academic offence should consult with a faculty member or faculty advisor.

The Academic Misconduct Policy is detailed in the University Calenders:


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For more information, contact CSD at 519-824-4120 ext. 56208 or email or visit the Student Accessibility Services website:

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