PPEM 300 Syllabus

PPEM 300: Horticultural Crop Diseases is an online course providing an introduction to the basic concepts and practices of Plant Pathology.  Students learn how to recognize and diagnose plant diseases, and how to avoid and manage disease development.

Personal feedback is provided on assignments and other questions.  The web-based format allows students to access module readings and complete assignments independently, on their own schedule, at home or elsewhere.  Students may tailor many assignments to their specific plant interests and locations.


Nancy G. Wenner

Nancy G. Wenner

Senior Research Assistant & Instructor

Phone (Office):  814-865-0717
Fax:  814-863-7217 (Main office Fax, so attn.: to Nancy Wenner)

Office address: 116 Buckhout Laboratory.  Office visits or phone calls may be scheduled through Canvas email contact.

Phone hours: 6 am to 2:30 pm; Please leave voice mail message. Canvas Email is preferred. 

E-mail:  Please use Canvas Inbox for all class communications and assignments, or to arrange phone or office appointments.


Nancy Wenner has been conducting research in Plant Pathology for 38  years on conifers, grapes, wheat, and other crops.  She holds a BS in Horticulture, an MS in Plant Pathology, and has worked in County Extension, as well as in the greenhouse, nursery, & landscape business.  Research projects often keep her in the laboratory, so it is best to contact her via Canvas e-mail to pose questions or discuss aspects of the course.  Phone calls or office visits can be arranged as needed via Canvas email.

Course Overview  

Students learn how to identify and manage horticultural plant diseases caused by a broad range of factors, including biotic (plant pathogens) and abiotic stresses (heat, drought, high salinity, freezing, etc.). The interaction of plants, the environment, and pathogens interact over time to influence disease development. Students learn what to look for to diagnose plant problems, and what treatments or management strategies are most useful to employ, when and why. The roles that plant pathogens play in national and international trade, bio-security, and natural environments are discussed.

PPEM 300 can be followed by more in-depth courses in plant-microbe interactions, mycology, nematology, phytobacteriology, air pollution impacts on terrestrial ecology, or forest pathology. 

The course is recommended for plant focused majors in Plant Sciences, Horticulture, Landscape Management, Urban Forestry, Arboriculture, and many others, but is also appropriate for non-plant majors, who are simply interested in growing healthy plants. Master Gardeners and Extension personnel may be able to expand their plant pathology expertise by taking this course. Students may customize PPEM 300 by choosing plant materials of their interest for many assignments. There are no specific course pre-requisites, but general biology is assumed and familiarity with common garden plants in the Northeastern US is needed and strongly recommended. [Can the student recognize common garden trees, shrubs, groundcovers, and flowers? (e.g. oaks, maples, crabapples, dogwood, lilac, roses, pachysandra, grapes, marigold, tomato, cucumber, etc.)] Please contact the instructor if there are questions regarding suitability.

PPEM 300 is composed of instructional online modules, richly illustrated with pictorial and video descriptions in the ‘Canvas’ course management system. No textbook is required. The course can be completed through the online modules, the supplemental reading materials provided, and links to online references. Students apply what they learn online by observing plants in their local area and locating specimens to photograph for disease diagnosis assignments.

Weekly assignments typically include reading/watching the modules, supplemental required reading, taking a quiz, and submitting one or two assignments. Assignments may be virtual lab experiments or plant diagnostic exercises, submitted via web in the Canvas system. There is one student-customized Plant Disease Assessment Report (PDAR), due the Tuesday after the Thanksgiving break. The course includes 5 quizzes, 5 diagnoses, 2 virtual labs, and a comprehensive final exam, all administered in the web-based format.

Plant diseases have significant influences on plant aesthetics, economics, edibility, and viability. They have had profound influences on world history, and roles in modern national and international trade and bio-security. Students will gain an appreciation of the impact that horticultural crop diseases can have on society and the environment, including how global trade of horticultural crops has resulted in the spread of pathogens important to agricultural crops and native plants.

Course Objectives

Students will learn:

  • the many causes of plant biotic and abiotic diseases.
  • how plants, the environment, and biotic and abiotic agents interact to cause disease.
  • to diagnose, assess the threat of disease, and manage key diseases of horticultural crops.
  • an appreciation of the economic and social impact that plant diseases have on horticultural crops, including how the world trade of these crops can result in the global spread of pathogens important to other agricultural crops, forest production and native plants in the environment. Students will become aware that plant pathology is a multidisciplinary branch of biology and that plant diseases have a significant impact on society and the environment.

Course Requirements

  • Internet connection for accessing course material, correspondence with instructor, taking quizzes and tests, and uploading assignments with original photographs.
  • Phone camera (or digital camera). Students must submit original photographs as part of their assignments. (Nothing fancy, just need moderate resolution and a steady hand for good focus!)
  • The ability to access, observe, photograph, and document plants in the student’s environment.

Photography for PPEM 300

Basic photography is required for PPEM 300 and most students use cameras on their cell phones, or inexpensive digital cameras.  A close-up setting is very useful to capture the disease signs and symptoms. Avoid blurry photos by using a steady hand and patience in finding a non-windy time/location with good lighting. Minimally, moderate resolution is needed to avoid pixilation in details.

*If using cell phone cameras, be aware that students have lost their photos because of software upgrades or lost or broken phones. Some students have had to retake all class photos.  Each student is required to take original photos and may not share images. To avoid problems, download or send your photos to your email address weekly, and keep them in a separate PPEM 300 photo file for safe-keeping – do this before you upgrade your phone software. NOTE: PPEM 300 photos must be original student images. Any use of internet images or will result in an immediate “0” for the assignment, and an Academic Integrity report, as posted in the PSU Academic Integrity policy. 

Course Prerequisites

There are no official course prerequisites, but it is assumed that the student will have:

  • a general biology course in high school or in college (3 credits) is assumed.
  • a general recognition of common garden plants in the northeastern U.S.  

Formal plant identification is not required, but a basic recognition of common yard and garden plants is needed for plant diagnoses. Students usually ‘Google’ to learn the genus of a common plant, if unknown. For example, students may ‘Google’ the plant ‘lilac’ to find that the genus name they need is “Syringa.”

Class Reading is intense in the first two months of the course to provide students more information to complete foliar diagnoses assignments before fall weather damages plants.  The latter part of the semester allows more time for independant work on PDAR and late term woody plant diagnoses.

Course Email

Course Email –Please always correspond via Canvas email.

Communication via the Course Management System (CMS), Canvas, is necessary to keep all course references together for both student and instructor. Canvas email can be forwarded to another email address to be received and read, the instructor will always request direct correspondence via Canvas.


Points Assignment / Evaluation – Please USE the Templates provided for all assignments.
100 points

Plant Disease Assessment Report (Student customized report) 

  • Proposal (Location/description/photo) = 20/100 points
  • 1st Draft PDAR = 30/100 points; (Late = "0")
  • Final PDAR = 50/100 points; (Late = "0")
150 points 5 Quizzes @ 30 points (45 minutes maximum length; open book, 15 questions)
50 points

2 lab reports (online) @ 25 points

  • Lab 1: Fungicide Resistance
  • Lab 2: Damping off
100 points 5 Disease Diagnosis Exercises @ 20 points
100 points Final exam (online during finals week)
*50 BONUS points 5 Bonus Disease Diagnosis OPTIONAL exercises @ 10 points  

*See below. Bonus diagnosis must be of opposite “type” from required 20-point diagnosis. (each Bonus diagnosis submitted via specifically designated Canvas Assignment)


Total - Grade is based on the number of points earned out of 500.

No Grades are dropped, and there are no grade curves.
Students can always estimate their progress by adding their accumulated points.


*50 points-5 OPTIONAL Bonus disease diagnosis exercises @ 10 points. Optional bonus points are added to the accumulated total. Bonus diagnoses must be of opposite “type” from that turned in for required 20-point diagnosis. E.g. one cannot do two powdery mildews or two hazard trees.

Students are to complete assignments individually; assignments are not collaborative.

The PLANT DISEASE ASSESSMENT REPORT (PDAR) is the student’s opportunity to customize the course content by evaluating a horticultural ‘planted’ location of their choice: part of a nursery or greenhouse or garden or park or home planting. This is the capstone assignment for this course requiring students to utilize what they have learned.

  • Students should read the instructions and begin to think about their site selection during the first week of class. (Lessons Tab, PDAR folder, read instructions and description) Review the PDAR_TemplateExamples.

  • The student must turn in their PDAR_Template with location/description/photo proposal by Tuesday Week 3 for instructor approval.  Unapproved topics will not be graded. Students must have a proposal approved before they work on their 1st Draft.
  • The 1st Draft of the PDAR is due Tuesday Week 9 and will be critiqued by the instructor and returned to the student for completion of the final PDAReport.  The 1st Drafts MUST be submitted on time and include progress made on the assignment.  The 1st Draft must match what was approved by the instructor in the proposal. The instructor will offer critique if the student submits more than the required 3 factors in the 1st Draft.
  • The Final PDAReport is due Tuesday Week 14. Note: this is due the Tuesday after Thanksgiving break; please plan accordingly.

*Please review the grading Rubrics for the 1st Draft and the Final PDA Report to see where points are earned. 

*The dates for the 1st Draft and Final PDAR are firm.  Late = “0”

*This assignment is worth 20% of your grade, so allow time to show me what you have learned!

Grading Scale (no grade curves)

Letter Grade

Percentage of total points

Lowest number of points earning the letter grade
93-100 465
A- 90-92 450
B+ 87-89 435
B 83-86 415
B-  80-82 400
C+  77-79 385
70-76 350
60-69 300
F < 59 295

Quiz Policy

Five quizzes are given online during a specified, scheduled time frame. For example, quizzes are ‘opened’ for student access for 2 days (Tues. 8 am--> Wed. until 11:55 pm), during which the student may select a convenient time to complete the 45-minute long interval open-book quiz.  Students must read the Modules in advance to complete the Quizzes in the 45-minute interval.  Quiz answers are based on information given in context in the Modules and other sources are not accepted.  The quizzes are “open book,” worth 30-points each, and composed of 15 questions.  The quizzes and exam are taken individually. They are not team activities.  Any sharing or teamwork from nearby computers can result in a “0” grade for both parties and Academic Integrity reports.

Suggestion:  Mark your calendar to remember to take the 5 Quizzes! Many students simply ‘forget’ to take the quizzes and risk losing 30 points.

It is the student’s responsibility to contact the instructor in order to arrange a time to make up a missed quiz within 1 week.

  1. Quiz #1:  30 points; Modules 1-2 -Week 2
  2. Quiz #2:  30 points; Modules 3-4 Week 4
  3. Quiz #3:  30 points; Modules 5-6 - Week 6
  4. Quiz #4:  30 points; Modules 7-9 - Week 8
  5. Quiz #5:  30 points; Modules 10-13 - Week 12

Please note that it is not possible to pass this course just by taking the quizzes. All other assignments must be completed satisfactorily as well. Quiz answers are found in the course materials.  Answers from other sources are invalid.


Final Exam policy:

A 100-point Final Exam will be given during finals week.  The online Final Exam is comprehensive and will be given in a specified scheduled time frame just as the quizzes are administered. The Final Exam is given in the same open-book manner as the quizzes and is machine graded.

Tentatively scheduled for Sun-Tue of Finals Week.  Dates will be finalized later in the semester.

Students must take the Final Exam individually and may not share answers or work collaboratively.

Course Schedule

Refer to your Canvas Syllabus and under Course Summary is a list of important dates and assignment deadlines.

9 Recommendations for Success in this Course

  1. Make sure your CANVAS settings allow you to receive the twice-weekly announcements and any assignment feedback. This information is critically important.
  2. READ the modules course material and assignments every week. All Quiz answers are in the course material and web links. Know what is important using the “Learning Objectives” and “Possible Quiz Questions” on the first page of each Module. Pay special attention to definitions and using proper terminology in your answers. Know the difference between disease “signs” vs “symptoms.”
  3. If you have any questions or problems, Please ASK! PPEM 300 is designed to be interactive, and questions are encouraged. Things sometimes "happen." If things happen to you, please inform the instructor sooner, not later. If you do not know which way to look for guidance, please inquire. If I do not know the answer, I will help you to find one!
  4. Use the grading 'Rubrics' to guide you in completing assignments. These charts show how points for assignments are awarded. Rubrics are found on the page with the associated assignment. Make sure to read the assignment feedback to help you with future assignments.
  5. Do not be intimidated! Plant diagnosis is a new skill that will require time, careful observation, and practice. If you submit an incorrect diagnosis for the first two diagnosis assignments, you may be asked to try again and resubmit. The "Plant Diagnosis Template" and Rubric will guide you to know what is required for a top grade. If you are stuck, look for the common diseases discussed in the Modules, review “Locating Disease Diagnosis Specimens,” or ask the instructor for a suggestion. Yes, really, ask me!
  6. Keep up with the weekly online Modules, Required Readings, and assignments. Learning is a stepwise and cumulative process. Reading assignments are concentrated during the early part of the course to provide information & examples to complete the foliar diagnostic exercises before fall weather damages the plants. Instructions, examples, and detailed explanations are in the Modules to help you with Diagnoses Exercises and Lab Experiments. You must read the Modules to know how to proceed. Do not allow lessons and assignments to pile up and become overwhelming.
  7. Do your own work! Any plagiarism, sharing, or use of other individual's words or photos will result in a “0” for the assignment and an Academic Integrity report, as per PSU policy.
  8. Download your photos for this course often and keep them in a safe place (off your phone/camera, in a duplicate folder). Many students have had to retake photos due to lost or damaged phones, or lost images due to software upgrades. Do not let this happen to you!
  9. Get outside and observe! Plants you pass daily on your way around town and campus can provide excellent diagnostic specimens. LOOK in your yards, around apartments, throughout town, campus, parking lots, or city planting beds. Plant diseases can be found wherever you find plants. Some diagnostic specimens can even be found in your refrigerator, supermarket, or salad!

Course History and Additional Information

PPEM 300 was designed and originally taught from 2007-2014 by Dr. Gary Moorman (now retired) to be a service course for students in horticulture who planned to work directly in the production or maintenance of woody ornamental, floricultural, vegetable, or fruit crops.  However, the content is also of interest to the student who grows plants for enjoyment, or who wishes to better understand the causes and control of factors involved in poor plant health. This course addresses practical issues in agriculture and the environment and may interest those students in other disciplines such as genetics, biochemistry, microbiology, meteorology, botany, entomology, nematology, and soil science. This is an introductory-level course and can be used by students to evaluate their interest in registering for additional courses in plant pathology, entomology, or other plant-health related courses.

The intended and unintended influences that governmental regulations and international agreements can have on the spread of plant pathogens and understanding of the complexity of the disease process will prepare students to better judge the threat of bio-terrorism to agriculture, the environment, and society in general. 



Technical Requirements

This course is offered online and it assumed you possess the minimum system requirements and computing skills to participate effectively. A list of technical requirements is listed on the World Campus' Penn State Technical Requirements page.

Minimum Skills

  • You should have an understanding of basic computer usage (creating folders/directories, switching between programs, formatting and backing up media, accessing the Internet).
  • You must be able to conduct word processing tasks such as creating, editing, saving, and retrieving documents.
  • You must be able to use a web browser to open web pages, download files, and search the Internet.
  • You must be able to use an e-mail program to send and receive messages and to attach and download documents/files.
  • You must be able to download and install programs or plug-ins from the Internet.

Accessibility Information

  • Accessibility statement for Canvas.


The term "Netiquette" refers to the etiquette guidelines for electronic communications, such as e-mail and discussion forum postings. Netiquette covers not only rules to maintain civility in discussions, but also special guidelines unique to the electronic nature of forum messages. Please review Virginia Shea's "The Core Rules of Netiquette" for general guidelines that should be followed when communicating in this course.

Support Services 

As a Penn State student, you have access to a variety of services and resources, including advising, tutoring, library services, career services, and more. Please visit the Student Support Services page for more information.

If you experience technology problems of any kind in Canvas, please select the Help icon and select "Report a Canvas Problem," "Chat with Support," or "Call Support." It is in your own best interest to be as specific as you possibly can. Vague descriptions of a problem only delay assistance. Try to include information such as: the specific course page, quiz question, etc. you were on; what you attempted to do when that failed; the exact language of any error message displayed on your screen; the date and time when your problem occurred; and any other pertinent information (does the problem happen consistently and always in the same way, etc.).

Online Students Use of the Library

As Penn State World Campus students, you have access to many of the materials that the library offers to students. The library website has a lot to offer, but can be overwhelming. A guide has been created to serve as your introduction to important library resources, services, and important pages within the library. The Online Student Library Guide is updated regularly by the online librarian and is intended to provide a level of comfort through introduction to help you feel comfortable navigating the library website to find valuable information for your coursework.

Penn State Policies

Log-In Policy

Students are expected to log-in regularly to keep up-to-date with announcements, discussions, etc. The class will progress at a regular pace throughout the semester and there are specific due dates and times for assignments, etc.

Academic Integrity

Academic integrity is the pursuit of scholarly activity in an open, honest and responsible manner. Academic integrity is a basic guiding principle for all academic activity at The Pennsylvania State University, and all members of the University community are expected to act in accordance with this principle. Consistent with this expectation, students should act with personal integrity, respect other students' dignity, rights, and property, and help create and maintain an environment in which all can succeed through the fruits of their efforts. Academic integrity includes a commitment not to engage in or tolerate acts of falsification, misrepresentation or deception. Such acts of dishonesty violate the fundamental ethical principles of the University community and compromise the worth of work completed by others (see Faculty Senate Policy 49-20, G-9 Procedures and the Code of Conduct).

Read the Academic Integrity Guidelines for the College of Agricultural Sciences

A lack of knowledge or understanding of the University's Academic Integrity policy and the types of actions it prohibits and/or requires does not excuse one from complying with the policy. Penn State and the College of Agricultural Sciences take violations of academic integrity very seriously. Faculty, alumni, staff and fellow students expect each student to uphold the University's standards of academic integrity both inside and outside of the classroom.

Educational Equity Statement

Penn State takes great pride to foster a diverse and inclusive environment for students, faculty, and staff. Acts of intolerance, discrimination, or harassment due to age, ancestry, color, disability, gender, gender identity, national origin, race, religious belief, sexual orientation, or veteran status are not tolerated and can be reported through Educational Equity at the Report Bias webpage.

Copyright Notice

All course materials students receive or to which students have online access are protected by copyright laws. Students may use course materials and make copies for their own use as needed, but unauthorized distribution and/or uploading of materials without the instructor's express permission is strictly prohibited. University Policy AD 40, the University Policy Recording of Classroom Activities and Note Taking Services addresses this issue. Students who engage in the unauthorized distribution of copyrighted materials may be held in violation of the University's Code of Conduct, and/or liable under Federal and State laws.

Counseling and Psychological Services (CAPS)

Many students at Penn State face personal challenges or have psychological needs that may interfere with interfere with their academic progress, social development, or emotional wellbeing. The university offers a variety of confidential services to help you through difficult times, including individual and group counseling, crisis intervention, consultations, online chats, and mental health screenings. These services are provided by staff who welcome all students and embrace a philosophy respectful of clients’ cultural and religious backgrounds, and sensitive to differences in race, ability, gender identity and sexual orientation.

Counseling and Psychological Services (CAPS)
Penn State Crisis Line (24 hours/7 days/week)
Crisis Text Line (24 hours/7 days/week)
Mental Health Services

(814) 863-0395
(877) 229-6400
Text LIONS to 741741

Accommodations for Persons with Disabilities

Penn State welcomes students with disabilities into the University's educational programs. Every Penn State campus has an office for students with disabilities. The Student Disability Resources Web site provides contact information for every Penn State campus. For further information, please visit the Student Disability Resources Web site.

In order to receive consideration for reasonable accommodations, you must contact the appropriate disability services office at the campus where you are officially enrolled, participate in an intake interview, and provide documentation. If the documentation supports your request for reasonable accommodations, your campus's disability services office will provide you with an accommodation letter. Please share this letter with your instructors and discuss the accommodations with them as early in your courses as possible. You must follow this process for every semester that you request accommodations.

Accommodations for Military Personnel

Veterans and currently serving military personnel and/or spouses with unique circumstances (e.g., upcoming deployments, drill/duty requirements, disabilities, VA appointments, etc.) are welcome and encouraged to communicate these, in advance if possible, to the instructor in the case that special arrangements need to be made.

Use of Trade Names

Where trade names are used, no discrimination is intended and no endorsement by the World Campus, Outreach and Cooperative Extension, the College of Agricultural Sciences, or The Pennsylvania State University is implied.

Subject to Change Statement

Please note that this Course Syllabus is subject to change. Students are responsible for abiding by such changes.