All course information is listed within this syllabus.

PPEM 300: Horticultural Crop Diseases (3 credits). This web-based course introduces 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 online format allows students to access module readings and complete assignments independently, on their own schedule, at home or elsewhere. A camera is required (phone cameras are fine) to complete assignments with original images. Some customized assignments allow students to utilize their choice of plant material. Students read the course materials and apply them to their own local plant environment to complete diagnoses and other reports.

Prerequisites: None

PPEM 300 fulfills a general education requirement for natural sciences (GN).


Instructor for PPEM 300

Christina Fox Call, Ph.D.
Assistant Professor

Department of Plant Pathology and Environmental Microbiology
115 Buckhout Laboratory
University Park, PA 16802

Phone (Office): 814-863-4292
E-mail: Please use Canvas Inbox for all class communications and assignments, or to arrange phone or office appointments.

Areas of Expertise

  • Agricultural science pedagogy and curriculum development
  • Plant and fungal reproductive genetics
  • Population ecology and genetics with GIS

Course Overview

Students will 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 over time 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 it is also appropriate for non-plant majors, who are simply interested in growing healthy plants. Master Gardeners, teachers, and Extension personnel can expand their plant pathology expertise with 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 module reading materials and videos. Supplemental reading link references are provided. 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 near the end of the semester. 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 taking this course will learn:

  • the many causes of plant biotic and abiotic diseases.
  • how plants, the environment, and biotic and abiotic agents interact to influence 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 our environment.

Course Requirements

  • Internet connection for accessing course material online, correspondence with an instructor, taking quizzes and tests, and uploading assignments with original student 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, a moderate resolution is needed to avoid pixelation in detail.

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 e-mail 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 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 students will have:

  • taken a general biology course in high school or in college (3 credits).
  • a general recognition of common garden plants in the northeastern United States.

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

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 independent work on the PDAR and late-term woody plant diagnoses.

Course E-mail

Please, always correspond via Canvas e-mail. Communication via the Course Management System (CMS), Canvas, is necessary to keep all course references together for both student and instructor. Canvas e-mail can be forwarded to another e-mail.

Course Schedule

For due dates, refer to the Course Summary on the Syllabus page in Canvas.

Graded assignments are in bold.

Week 1: Module 1 & 2 & Required Reading Links

Module 1-Introduction to Plant Pathology
Example: Rose black spot
Video lab "Symptoms of Plant Disease" Video Tutorial. Know the difference: symptoms vs signs.

Required Reading links are found on the Module 1 Overview page:

  1. Definitions and pathogen characteristics for class
  2. Rose black spot
  3. Rose diseases

Read PDAR (Plant Disease Assessment Report) explanation and instructions. Module 1 Activities. Found at the end of Module 1.

Module 2-Characteristics of Biotic Pathogens
Example: Bacterial leaf spots on Hedera and Capsicum
Video lab "Signs of Plant Disease" Video Tutorial
Note: Know the difference between plant pathology terms - "Symptoms" vs "Signs!"

Read Module 2

  1. Characteristics of biotic pathogens (fungi and bacteria)
  2. Characteristics of biotic pathogens (phytoplasmas, viruses, viroids, vascular plants, allelopathy)

Select site for PDAR (Plant Disease Assessment Report) assignment and fill in Proposal Template. Description & instructions under Module 1 Activities.
Reminder: Review for QUIZ 1 covering Modules 1 & 2 for next week. Quiz 1 is found under Module 2 Activities.

Week 2: Modules 3 & 4 & Required Reading Links

QUIZ #1 on Modules 1 & 2 & Required Readings (30 pts). Found on Module 2 Activities.
Remember to review Quiz Taking Hints before taking the Quiz!

Module 3-Disease Control Strategies
Non-chemical control of diseases
Example: Plum pox virus
Video lab on "Magnification for Viewing Specimens Video Tutorial"

Reading links are found on the Module 3 Overview page:

  1. Plum pox virus in woody ornamentals
  2. Examining spores and lesions

PDAR (Plant Disease Assessment Report): Choose site and complete Proposal Template, Page 1. Found under Module 1 Activities.

Module 4-Chemical Control of Diseases and Fungicide Resistance

Reading links are found on the Module 4 Overview page:

  1. Fungicide resistance management
  2. Gray mold or Botrytis

Watch the videos for the Botrytis Fungicide Resistance Lab, Part 1 & 2. Module 4 Activities.
Botrytis Fungicide Resistance Lab Report – Use the templates provided. Due Week 4.

Reminder: Work on Proposal for PDAR Due Tuesday Week 3.

The Plant Disease Assessment Report (PDAR) is a student-customized assignment and is the "Capstone" report for this course. This assignment is worth a total of 100 points, so it should be given careful consideration. Read the assignment description, considerations, and examples for selecting your site.

Use the PDAR Template Form and fill out Page 1 only now to submit the location, size, description/purpose, and photos for your Plant Disease Assessment Report by Week 3 for the instructor to approve. Keep all pages of the PDAR together, but only fill out Page 1 for the Proposal. Submit the form, with the appropriately labeled photos, preferably embedded in the PDAR form.

Please paste photos in the Proposal Template, including at least 3 photos large enough to show your site from all sides and for your instructor to see! (Photo size should be ½ page width.)

The PDAR Proposal is worth 20 points and functions in 2 ways:

  1. It shows me that the site you have selected is appropriate and will not present problems for you. Sites that are too large, too small, overly simple or complicated, or otherwise unsuitable will need to be revised. Ask yourself if you can identify all plants at your site to genus?
  2. Choosing a site early in the semester allows you to be thinking about your site as you read through the various influences on disease development in the course modules.

The First Draft of the PDAR is due Tuesday Week 9, and the Final Report is due Tuesday Week 14. Both of these assignments are graded, and neither can be late or a "0" grade will result. Be sure to check the grading rubric for this assignment to see where points are gained or lost.

Week 3: Module 5 & Required Reading Links

Due: Plant Disease Assessment Report (PDAR) Proposal: Location, description, & photo must be finalized and submitted for approval by the instructor before you can proceed (20 pts).
Read the instructions for this student-customized assignment.

Module 5-Methods of Applying Chemical Controls (Sections 1-4)
Genetic, physical, and biological disease controls

Reading link is found on the Module 5 Overview page:

  1. Heat treatment of Soil

Reminders: Lab Report 1, Fungicide Resistance due Tuesday Week 4.
Review for QUIZ 2 for Week 4.

Week 4: Module 6 & Required Reading Links

Lab Report 1, Fungicide Resistance, online, 25 pts. 
Virtual experiments in Petri plates. Please complete the experiment and submit it. Please use the Template forms provided for submission. Instructions, explanations, and template are in Module 4.

  1. Botrytis fungicide resistance experiment, Parts 1 & 2 details.
  2. Botrytis fungicide resistance report template.

QUIZ #2 on Modules 3 & 4 & Readings (30 pts).
Remember to review Quiz Taking Hints before taking the Quiz!

Module 6-Foliar Diseases (Sections 1-5)
Foliar diseases: Powdery mildews, anthracnose and leaf spots

Reading links are found on the Module 6 Overview page:

  1. Powdery mildew
  2. Powdery mildew host cross-listing
  3. Anthracnose
  4. Volutella blight

Lab: Disease Diagnosis Video Tutorials – Listen to Dr. Moorman's videos on diagnosing the following plant diseases and take notes. This information may help you with your plant disease diagnosis reports, or even give you quiz answers!

  1. Oak leaf blister
  2. Powdery mildew
  3. Dogwood anthracnose
  4. Zinnia leaf spots
  5. English ivy leaf spots
  6. Volutella blight

Reminders: Disease Diagnosis 1 (& Optional Bonus) Leaf Spot, due Tuesday; Module 6 has many examples. RE-watch Dr. Moorman's Video in Module 2, Section 5 for a great explanation of 'Signs vs Symptoms.' This video will also give ideas and explanations for disease diagnosis specimens.

Week 5: Module 7 & Required Reading Links

Disease Diagnosis Exercise 1: Photograph and identify a Leaf spot. Identify the plant, and submit the information and photo(s) on the disease diagnosis template form.

Hint: Review Module 6, & Module 2; Section 2 has some good diagnosis suggestions, as does the video at the end of Module 2. Read the LocatingDiseaseDiagnosisSpecimensPPEM300.pdf for more hints & suggestions. If you are looking at trees on the University Park campus, Lorax is a good aid to helping with tree identification. If you go to the Arboretum at Penn State, you may find their Plant Finder ID helpful.

Optional Bonus Disease Diagnosis 1. Photograph and identify a Leaf spot different from the one used in the 20-point required lab exercise. Submit the information on the appropriate template form. (10 pts.) This is the only Bonus diagnosis that permits the same 'type' of disease to be submitted (i.e., two different leaf spot diseases).

Module 7-Rusts, Needlecasts, and Downy Mildews
Video Lab on Cedar-Rusts.

Required Reading links are found on the Module 7 Overview page:

  1. Cedar-apple and other Rusts
  2. Needlecasts
  3. Downy mildew

Reminders: Disease Diagnosis 2 (& Optional Bonus) due Tuesday.
Review for QUIZ 3 for next week.

Week 6: Module 8 & Required Reading Links

Disease Diagnosis Exercise 2: Photograph and identify a Rust or a Powdery mildew. Identify the plant, and submit the information and photo(s) on the disease diagnosis template form. (20 pts.)

Optional Bonus Disease Diagnosis 2. Photograph and identify a Powdery mildew if the above sample was a Rust or vice versa. Submit the information and photo on the appropriate template form. (10 pts.) Note: The primary and the Bonus disease diagnosis must be different 'type' diseases—one may not submit two Rusts or two Powdery mildews.

QUIZ #3 on Modules 5-6 & Required Readings (30 pts).
Module 8-Root Rots (herbaceous plants)
Root rots (herbaceous plants): Thielaviopsis, Rhizoctonia, Pythium

Required Reading links are found on the Module 8 Overview page:

  1. Pythium
  2. Thielaviopsis
  3. Rhizoctonia
  4. Cylindrocladium
  5. Fungal root rots and chemical fungicide use
  6. Damping-off

Reminders: Lab Report 2, Damping Off, due Tuesday.
Work on 1st Draft PDAR.

Week 7: Module 9 & Required Reading Links

Lab Report 2, Damping-off, 25 pts. An online, virtual lab experiment. Please complete the experiment and submit it. (Please use the template forms provided for submission.) Instructions are in Module 8 Activities, watch the video, use Damping-Off template.

Module 9-Root Rots
Root rots (woody plants): Inonotus, Armillaria, Ganoderma; Hazard trees.
Root rots: Verticicladiella, Phytophthora
Labs - Kits for diagnosis, Plant disease clinic services
Video – Root and Butt Rots

Required Reading links are found on the Module 9 Overview page:

  1. Hazard trees
  2. Inspecting trees for hazards
  3. Phytophthora

Reminder: Disease Diagnosis 3 (& Optional Bonus) due Tuesday.
Review for QUIZ 4 for next week.
Work on 1st Draft PDAR.

Week 8: Module 10 & Required Reading Links

Disease Diagnosis Exercise 3, Photograph and identify a plant affected by root rot, stem rot, or fruit rot. Identify the plant and submit the information and photo(s) on the disease diagnosis template form.

Optional Bonus Disease Diagnosis 3. Photograph and identify a different sample from the one used in the lab exercise. If you did a root rot, then do either a stem rot or a fruit rot, etc. Submit an original photo and report on the appropriate template. (10 pts.)

QUIZ #4 on Modules 7, 8, 9 & Required Readings (30 pts).
Module 10: Vascular Wilts
Vascular wilts: Xanthomonas, Ralstonia, Xylella
Vascular wilts: Verticillium wilt, Fusarium wilt, Bacterial wetwood, Dutch elm disease, Oak wilt
Lab Videos:

  • Verticillium wilt
  • Wetwood (slime flux)

Required Reading links are found on the Module 10 Overview page:

  1. Geranium diseases
  2. Geranium bacterial blight
  3. Bacterial wilt, Ralstonia
  4. Bacterial leaf scorch
  5. Elm diseases
  6. Oak wilt
  7. Wetwood - slimeflux

Reminders: 1st Draft PDAR due Tuesday – No late submissions.

Week 9: Module 11 & Required Reading Links

The First Draft of your Plant Disease Assessment Report. (30 points, if complete and on time.) See the grading rubric for details. No late submissions. Late = zero. Turn it in even if it is incomplete.

Module 11-Cankers and Galls
Cankers - Botryosphaeria, Sphaeropsis (Diplodia), Cytospora, fire blight
Galls: azalea flower gall, crown gall, black knot, honey locust knot
Video labs:

  • Botryosphaeria
  • Cytospora
  • Crown gall
  • Fire blight
  • Sphaeropsis, Diplodia

Reading links are found on the Module 11 Overview page:

  1. Cankers on deciduous trees
  2. Botryosphaeria canker
  3. Diplodia on pine
  4. Canker stain
  5. Fire blight
  6. Cytospora canker on spruce
  7. Disinfecting tools and equipment
  8. Crown gall
  9. Azalea and Rhododendron diseases (Azalea leaf and flower gall)
  10. Black knot (on Prunus)

Reminders: Disease Diagnosis 4 (& Optional Bonus) due Tuesday.

Week 10: Module 12 & Required Reading Links

Disease Diagnosis Exercise 4: Photograph and identify a hazard tree or a wood rot. Identify the plant, and submit the information and photo(s) on the disease diagnosis template form. (20 pts.)

Optional Bonus Diagnosis 4. Photograph and identify a different sample from the one used in the lab exercise. If you did a hazard tree, then do a wood rot for the Bonus or vice versa. Submit the report and original photo on the appropriate template. (10 pts.)

Module 12-Virus Diseases and Declines
Virus diseases: INSV, TMV, CMV
Declines: Diseases of complex etiology
Video lab - Declines

Required Reading links are found on the Module 12 Overview page:

  1. Insect vectored plant pathogens on woody ornamentals
  2. Impatiens necrotic spot virus - INSV
  3. Cucumber mosaic virus - CMV
  4. Tobacco mosaic virus - TMV
  5. Over-fertilization

Reminders: Disease Diagnosis 5 (& Optional Bonus) due Tuesday.

Week 11: Module 13 & Required Reading Links

Disease Diagnosis Exercise 5: Photograph and identify a disease-related gall (not an insect or mite gall) or a canker. Identify the plant, and submit the information and photo(s) on the disease diagnosis template form. (20 pts.) Last Diagnosis!

Optional Bonus Disease Diagnosis 5. Photograph and identify a gall or canker different from the one used in the lab exercise. If you did a gall, then do a canker or vice versa, for the bonus points. Submit and attach the information and original photo to the appropriate template. (10 pts.) Last optional BONUS Diagnosis!

Nematodes: root-knot, foliar, dagger and lesion

Required Reading links are found on the Module 13 Overview page:

  1. Nematodes on woody ornamentals
  2. Foliar nematode – Aphelenchoides

Assessing the threat of disease in greenhouses.
Assessing the threat of disease in nurseries.
Assessing the threat of disease in gardens/parks/plantings.

Reminder: Review for QUIZ 5 for next week. (Last Quiz!)
Work on Final PDAR.

Week 12: Module 14 & Required Reading Links

QUIZ #5 on Modules 10, 11, 12, 13 & Required Readings (30 pts).
Module 14-Pathogens of Global Importance Carried on Horticultural Crops
Pathogens of global importance carried on horticultural crops.
The threat of foreign pathogens: Chestnut blight, Dutch elm disease, Phytophthora ramorum.

Reminder: Catch up on any tardy Lab Report or Plant Disease Diagnoses 1-5 & Bonuses.
If you submit a late assignment, please notify the instructor.
Next Tuesday (Week 13) is the absolute deadline for any of these outstanding assignments.

Note: Please remember that the Plant Disease Assessment Report is in Week 14. This report cannot be submitted late, due to the time required for grading. Late = zero.

Week 13: Module 15 & Required Reading Links


All remaining (late) Lab Reports and Diagnoses/Bonus Diagnoses are due Tuesday Week 13. Last opportunity to catch up with these assignments.

The Plant Disease Assessment Report is due in Week 14; Late= zero. Turn it in even if incomplete. Partial credit is better than none. This part of the assignment is worth 50 points. No late submissions are permitted due to the time required for grading.

Readings key to completing the PDAR:

  1. Sources of plant pathogens
  2. Assessing the threat of disease in greenhouses
  3. Assessing the threat of disease in nurseries
  4. Assessing the threat of disease in gardens/parks/plantings

Week 14

The Final copy of Plant Disease Assessment Report (50 points).
Turn in the PDAR even if it is incomplete. Partial credit is better than none.

Week 15: Review all modules

Review for the partially comprehensive Final Exam, given during Final Exam week, Week 16. Plan your time to take the Final Exam and mark it on your calendar so you will not forget!

Finals Week

FINAL EXAM IS DURING FINALS, (100 pts.). As with quizzes, it is open-book and given online at a scheduled time interval. The final exam is partially cumulative and fully machine graded, with no partial credit. Plan your time to take the Final Exam and mark it on your calendar so you will not forget!


Please use the templates provided for all assignments.

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 proposal is worth 20 out of 100 points.
  • 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 PDA Report. 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 1st Draft PDAR is worth 30 out of 100 points.
  • The Final PDA Report is due Tuesday, week 14. The Final PDAR is worth 50 out of 100 points.
  • 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 = zero points.
  • This assignment is worth 20% of your grade, so allow time to show me what you have learned!

Quiz Policy

Five quizzes are given online during a specified, scheduled time frame. For example, quizzes are 'opened' for student access for 2 days, 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 the 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 final 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. (IP addresses can be monitored!)

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.

The final exam is tentatively scheduled for Sunday through Tuesday 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.

Important Assignment Closure Dates/Times

Most assignments are due on Tuesdays and must be uploaded to Canvas by 11:59 p.m. This gives you the end of the previous week, the weekend, or Monday to complete the work.

Online courses can provide some flexibility. If Tuesdays are not a good assignment evening for you or you prefer to take a quiz on Thursday, please contact the instructor. An alternate day can be selected if the student is consistent. However, the PDAR 1st Draft (due Tuesday, week 9) and Final PDAR (due Tuesday, week 14) due dates cannot be changed.

PDAR Proposal. 20 points. If the instructor suggests changes to the student proposal it may be re-submitted without penalty.

The 1st Draft PDAR. 30 points. Hard deadline. No late submissions are permitted for the PDAR 1st Draft and Final copy due to the time needed for grading and personal feedback. Late = zero points. Turn it in even if it is not complete. Partial credit is better than none.

The Final PDAR. 50 points. Hard deadline. No late submissions are permitted for this assignment due to the time needed for grading and personal feedback. Late = zero points. Turn it in even if it is not complete. Partial credit is better than none.

All "late" Lab Reports and Diagnosis/Bonus assignments are due in week 13.

Grading Policy

  • Five Quizzes
    • Each quiz is worth 30 points.
    • Each quiz is 15 questions, open book, and has a time limit of 45 minutes.
  • Plant Disease Assessment Report (a student customized report)
    • Worth a total of 100 points. 
    • Your proposal (location/description/photo) is worth 20 out of 100 points.
    • 1st Draft PDAR is worth 30 out of 100 points. Late = zero points.
    • The Final PDAR is worth 50 out of 100 points. Late = zero points.
  • Two Virtual Lab Reports (online)
    • Each lab report is worth 25 points.
    • Lab 1: Fungicide Resistance (found in Module 4) 
    • Lab 2: Damping Off (found in Module 8) 
  • Five Disease Diagnosis Exercises
    • Each is worth 20 points. Each diagnosis is submitted via a specifically designated Canvas assignment.
    • Leaf Spot
    • Powdery Mildew or Rust Disease
    • Root Rot, Stem Rot, or Fruit Rot
    • Hazard Tree or Wood Rot
    • Canker or Disease-Related Gall
  • Final Exam (online during finals week)
    • The final exam is worth 100 points.
  • Five Bonus Disease Diagnosis Exercises (optional)
    • Each is worth 10 points, for a possible total of 50 bonus points. Each bonus diagnosis is submitted via a specifically designated Canvas assignment.
    • Bonus diagnosis must be of the opposite "type" from the required 20-point diagnosis.
    • Bonus Leaf Spot
    • Bonus Powdery Mildew or Rust Disease
    • Bonus Root Rot, Stem Rot, or Fruit Rot
    • Bonus Hazard Tree or Wood Rot
    • Bonus Canker or Disease-Related Gall

The total amount of points for this course (excluding bonus points) is 500 points. Your grade is based on the number of points earned out of 500.

Grading Criteria
Requirement Cumulative Point Value
Quizzes 150
Plant Disease Assessment Report 100
Labs 50
Disease Diagnosis Exercises 100
Final Exam 100
TOTAL: 500
*5 Bonus Disease Diagnosis Exercises (Optional) 50

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

*50 bonus points: Optional Disease Diagnosis Exercises are worth 10 points each. Optional bonus points are added to the accumulated total. Bonus diagnoses must be of an opposite "type" from those turned in for the 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.

Grading Scheme
Letter Grade Percentage Lowest Number of Points Earning the Letter Grade
A 100% – 93% 465
A- < 93% – 90% 450
B+ < 90% – 87% 435
B < 87% – 83% 415
B- < 83% – 80% 400
C+ < 80% – 77% 385
C < 77% – 70% 350
D < 70% – 60% 300
F < 60% 295

Please refer to the University Grading Policy for Undergraduate Courses for additional information.

NOTE: If you are planning to graduate this semester, please communicate your intent to graduate to your instructor. This will alert your instructor to the need to submit your final grade in time to meet the published graduation deadlines. For more information about graduation policies and deadlines, please see "Graduation" under World Campus Student Resources.

Nine 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 to your success!
  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 use the 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 given suggestions and asked to revise 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 the document "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 and 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 individuals' words or photos will result in a zero for the assignment and an Academic Integrity report, as per PSU policy.
  8. Download the photos you take 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. Those students that are interested in how other disciplines (such as genetics, biochemistry, microbiology, meteorology, botany, entomology, nematology, and soil science) are integrated into a branch of biology that addresses the practical issues of agriculture and the environment are also encouraged to take this course.

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

This is an introductory-level course that can be used by students to evaluate their interest in registering for additional courses in plant pathology, entomology, or other plant-health-related courses.

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 an introduction to help you feel comfortable navigating the library website to find valuable information for your coursework.

Technical Requirements

This course is offered online and it is assumed you possess the minimum system requirements and computing skills to participate effectively. A list of technical requirements is listed on 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.

Getting Help With Canvas Courses

Canvas support is available 24/7 via chat or phone.

It is in your own best interest to be as specific as you possibly can. 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.).

Support Services

As a student, you have access to a variety of services and resources, including advising, tutoring, library services, career services, and more. Please visit the following resources for more information:

Accessibility Information


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

Penn State Policies

Login 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.

Course Availability

Your course will be available to you beginning the first day of class and will remain open for one year. After one year the course will close.

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).

Please 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 in fostering 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 page.

Privacy Policies

For information about Penn State's privacy statement and what it encompasses, please read their Web Privacy Statement. Visit Penn State's FERPA Guidelines for Faculty and Staff page for information regarding its rules governing the privacy of student educational records.

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 AD40, 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 their academic progress, social development, or emotional well-being. 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.

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 website provides contact information for every Penn State campus. For further information, please visit the Student Disability Resources page.

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' 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 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.

Course Availability

If you're ready to see when your courses will be offered, visit our public LionPATH course search to start planning ahead.