PBIO*4070 Biological and Cultural Control of Plant Diseases

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NOTE: This course is cancelled for W23.
The following description is for the course offering in Winter 2022 and is subject to change. It is provided for information only. The course outline distributed to the class at the beginning of the semester describes the course content and delivery, and defines the methods and criteria to be used in establishing the final grades for the course.

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:

  • Undergraduate

Academic Department (or campus):

Department of Plant Agriculture



Semester Offering:

  • Winter

Class Schedule and Location:

Please refer to WebAdvisor for class schedule and location.

Learning outcomes:

At the end of this course, students 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 undergrad students

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

Lecture Content:

Topics to be covered* in lectures include:
  • 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:

There are no labs scheduled for this class.


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).

Course Assignments and Tests:

Assignment or Test Contribution to Final Mark Learning Outcomes Assessed

Weekly Discussions


4, 7, 8

Bi-weekly Quizzes


1, 2, 3

Term Paper


4, 5

Term Paper Presentation 



Research Proposal

25% 4, 6


Final examination:

There is no final exam for this course.

Course Resources:

Required Texts:

There are no required texts for this course.

Recommended Texts:

Campbell, R. 1989. Biological Control of Microbial Plant Pathogens

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

Biological Control of Plant Pathogens (Website)
Pal, K. K. and B. McSpadden Gardener, 2006. Biological Control of Plant Pathogens. The Plant Health Instructor DOI: 10.1094/PHI-A-2006-1117-02.
Lab Manual:

Not applicable.

Other Resources:

CourseLink (Website) https://courselink.uoguelph.ca

Lectures presented in Power Point as well as any additional material can all be found on CourseLink

Field Trips:

Not applicable.

Additional Costs:

Not applicable.

Course Policies:

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 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.

Course Policy on Group Work:

All work performed in class is done on an individual basis and should be the sole work of the student submitting the assignment.

Course Policy regarding use of electronic devices and recording of lectures:

Electronic recording of classes is expressly forbidden without consent of the instructor.  When recordings are permitted they are solely for the use of the authorized student and may not be reproduced, or transmitted to others, without the express written consent of the instructor.

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 sas@uoguelph.ca or visit the Student Accessibility Services website: http://www.uoguelph.ca/csd/.

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