Lesson Structure: Plant Pathology BHT206

There are 8 lessons:

1. Introduction

• Overview of plant disease
• Diagnosis of problems: nutritional, environmental, pathological
• Symptoms
• Common terminology

2. Types of Diseases

• Morphological changes
• Necroses
• Hypoplases
• Hyperplases
• Types of pathogens: viruses, bacteria, actinomycetes, fungi, nematodes
• Techniques for diagnosing plant diseases: optical equipment, preparing pathogens for observation, culture methods, inoculation, etc
• Plant viruses; detection and diagnosis
• Plant nematodes
• Case study: Australian plant nematodes
• Main types of diseases
• Spots
• Rots
• Cankers
• Galls
• Mildews
• Rusts
• Moulds
• Wilts
• Scabs
• Others
• Using a key to diagnose diseases in plants

3. The Lifecycle of a Disease

• Inoculation
• Penetration
• Infection
• Growth and reproduction
• Dissemination
• Methods of penetration by bacteria and nematodes
• Lifecycle of nematodes
• Fungal biology
• Role of insect spreading fungal and bacterial pathogens

4. Control Techniques

• Sanitation
• Resistant Plant Varieties
• Biological Controls
• Soil Drenches/dips
• Chemical Controls
• Nematicides
• Soil fumigants
• Contact poisons
• Fungicides and the environment
• Systemic fungicides
• Misters, dusters, blowers, sprayersSpray maintenance and cleaning
• Natural controls: cultural, physical, biological, etc
• Terminology

5. Selected Pathogen Diseases Ornamentals

• Fungi affecting turf
• Phytopthera cinnamomi
• The process of tree decay: Shigo
• Case study: how phytopthera cinnamomi kills a susceptible Eucalyptus
• Peach powdery mildew
• Rose powdery mildew
• Honey fungus on rhododendrons and azaleas
• Petal blight on rhododendrons and azaleas

6. Selected Pathogen Diseases Crops

• Sclerotinia rot in vegetables
• Nematodes and citrus production
• Citrus diseases: scaly butt, lemon crinkle, citrus canker
• Brown rot
• Fire blight
• Apple fruit rot caused by trichoderma harzianum
• Prunus necrotic ringspot virus in cut flower roses
• Potato and tomato blight
• Club root

7. Non-Infectious Diseases

• Nutritional disorders
• Lack of water
• Excess water
• Other environmental problems
• Disorders caused by man: mechanical damage, pollution
• Case Study: Air pollution
• Other disorders: genetic, disturbed growth
• Non parasitic turf problems

 8.   Special Project

Each lesson culminates in an assignment which is submitted to the school, marked by the school’s tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Learning Goals: Plant Pathology BHT206

• The first part of the course develops an understanding of the different types of problems which can occur and how to identify them.
• Terminology is covered in some depth, so as to enable the student to be able to read and understand books and articles written about plant diseases. Other major topics of study include “symptoms” (ie. necroses, hypoplases, hyperplases, etc), “types of pathogens” (ie. viruses, bacteria, fungi, nematodes, etc), and the life-cycle of a disease.
• The second part of the course looks at how to control pathology problems. The major methods of controlling pathogens (ie. sanitation, resistant varieties, biological controls, soil drenches and chemical sprays, etc.) are all studied, along with types of equipment and safety.
• The third part of the course looks at some of the most common plant pathology problems in commercial horticulture, how to identify them and how they are controlled.
• Describe a range of pathological problems that affect plants.
• Describe symptoms of a range of diseases that affect plants.
• Describe disease life cycles and explain how this knowledge can be applied in disease control
• Explain the methods used to control diseases
• Demonstrate a comprehensive knowledge of a particular plant pathogen.
• Identify and describe a range of non-infectious diseases and problems that affect plants
• Identify and describe a range of common pathogens that affect ornamental plants.
• Identify and describe a range of common pathogens that affect crop plants

Practicals – What You Will Do

•  The first part of the course develops an understanding of the different types of problems which can occur and how to identify them.
•  Terminology is covered in some depth, so as to enable the student to be able to read & understand books & articles written about plant diseases.
  Other major topics of study include “symptoms” (ie:  Necroses, Hypoplases, Hyperplases, etc), “types of pathogens” (ie: Viruses, bacteria, fungi, Nematodes, etc), and the lifecycle of a disease.
•  The second part of the course looks at how to control pathologyproblems. The major methods of controlling pathogens (ie: Sanitation, resistant varieties, biological controls,
  soil drenches & chemical sprays, etc) are all studied, along with types of equipment & safety.
•  The third part of the course looks at some of the most common plant pathology problems in commercial horticulture, how to identify them and how they are controlled.
•  Some of the problems studied include cinnamon fungus, tree decay, powdery mildew, nematodes, brown rot, blights, turf fungi, damping off and non infectious problems
  such as temperature burns, air pollution, wind burn and excessive light.
•  The course is a highly practical one involving as much time in practical/field work as it does theory.
•  No prior formal training is required, though anyone undertaking this course is expected to have some experience in horticulture (either having worked in the industry or
  having studied in some related discipline.

FREQUENTLY ASKED QUESTIONS

Here is a list of the most often asked FAQ’s.

General

Q. Why should I enrol with the Academy for Distance Learning?
A. Here at ADL, our students are our priority – we treat everyone as a unique individual.

Q. Do I need to buy text books?
A. No, as each module has been written by highly qualified industry professionals. The content of the material is presented in such a way that text books are not required. However, if you require additional reading your tutor will be able to supply a list.

Q. What happens if I have to stop studying for a while? (eg. become sick, go on holidays, have a baby, move house, etc)
A. It’s OK to take a break and start up your study at a later point in time. Just let us know.

Q. Is there an age limit?
A. There is no maximum age limit. We do however, have a minimum age limit of 18 years. Below that age parental consent would be required.

Q. Are your courses up-to date?
A. Our courses are revised and updated on a rotation system.

Q. Do you have a Cancellation policy?
A. Yes. We have a cancellation policy that is fair and equitable. For further details please click here.

Q. Will I have any opportunity to engage with other students?
A. We have a Student Community group based on facebook! If you don’t have a facebook account already, you could make one just for talking with fellow students on the group.

Enrolment

Q. When can I enrol/start?
A. You may enrol and start at any time of the year – it’s all self- paced.

Q. Can I study from anywhere in the world?
A. Our courses are available to anyone, anywhere in the world from the comfort of your own home. The course content is relevant to any country, culture or economy.

Q. How long do I have to complete the course?
A. You complete the course at any time that is convenient for you.

Q. Completing a 100 hour module – how long will it take?
A. For some students a 100 hour module will take approximately to 3- 6 months to complete. Others take less time and some even longer.

Assessment

Q. Assessment – how does it work?
A. For each 100 hour module you are assessed by assignments (at the end of each lesson) and a final one and a half hour exam (or you may elect to complete a Project, instead of sitting the exam) – the choice is yours – you sit for the exam in your own location.

Q. I don’t cope well with exams – what can I do?
A. You may elect to undertake a Project (set by your tutor) instead of sitting the exam. Projects are completed from your home and can usually take a couple of weeks to complete.

Q. If my assignment is not up to standard is there an opportunity to resubmit my work?
A. Yes –

Q. How many assignments do I need to complete for each module?
A. At the end of each lesson, there is an assignment – so if a course has say, 10 lessons, there would be 10 assignments.

Q. I am having difficulty attending workshops/industry meetings, what can be done?
A. If your course requires attendance at workshops, conferences, or industry meetings; alternative arrangements can be made in your country.

Qualifications

Q. What qualification will I receive?
A. For individual modules, you would be awarded a Certificate endorsed by TQUK (Training Qualifications, UK), providing you complete all assignments and the exam. If you just want to complete only the assignments and not sit for the exam or finish a Project, then a Letter of Achievement would be awarded. For more details on qualifications available please click here.

Q. Can I customize my diploma/higher qualification?
A. Not all educational institution’s certificates /diplomas meet everyone’s needs. The opportunity to Design Your Own Diploma at the Academy (subject to our approval) is an added bonus, not found at other colleges. You choose modules that you think will help you in achieving your goal.

Q. What do I get when I complete the course? Will I receive a transcript?
A. At the completion of all courses and providing all assignments and exam requirements have been met, you will receive your Award and a Transcript.

Tutors

Q. Our tutors – who are they?
A. We appoint Tutors and require that they must be currently active in their industry, with at least 5 years’ experience in their chosen profession.

Q. Can I contact my tutor at any time?
A. Yes – you have unlimited access to your tutor via email through our Online Classroom. You can always leave a message with ADL requesting your tutor to contact you. You decide on how much or how little contact you wish to have.

Q. Practical work – How is this done?
A. To find out more about this part of the course please visit the section on How Our Courses Work here.

Excerpt From The Course

TURF DISEASES

Although there are a variety of conditions such as lack of water, poor nutrition, and waterlogging which can cause the most common symptom on lawns – discoloured turf, it can also be caused by a number of diseases and so the cause is worth investigating.

Fungi on Turf

Let us firstly recap on what we already know about fungi. Fungi are a primitive form of plant life which, unlike green plants (such as grasses), are unable to produce their own food through photosynthesis.  This means that fungi must obtain their food from other life forms (plants or animals – living or dead).  Some types of fungi are in fact of benefit to us, living on dead organic material and helping decomposition.  Other fungi however attack living organisms, feeding from and causing deterioration to the life form it attacks.

Most fungi are made up of a body comprised of filaments which grow hyphae. Together, groups of filaments are called mycelium.  When the mycelium establishes sufficiently and has the right conditions, it will produce fruiting bodies (e.g. the umbrella which we eat of a mushroom – this is the mushroom fruiting body which has grown up from a mass of hyphae growing in organic matter in the soil).  The fruiting bodies of fungi can vary greatly in shape and size.  On maturation, one fruiting body will release many (sometimes thousands) spores (i.e. the equivalent of seeds in flowering plants).  These spores are microscopic and move in the air, soil, water etc. They can lie dormant sometimes for years, until the conditions are suitable for growth.  Under the right conditions, the spores will grow to produce a new mycelium.

When a plant leaf, stem, root, flower, or fruit is affected by fungi, hyphae grow into the body of the living plant feeding off its tissue and (depending on the severity of the type of fungus) causes anything from a slight ill effect through to death of part of the plant, or whole plant.

Damping Off

This refers to several different types of fungus (Pythium, Phytopthora etc) which attack young seedlings causing them to rot at ground level.  This disease is of significance in both the nursery industry and in turf care. In turf, damping off will show in a newly sown lawn as a reddening or bronzing of grass leaves in patches, particularly in places where grass is dense, or in wet spots.  Overwatering is a significant cause of damping off.  Reduced watering as well as application of a fungicide (e.g. Zineb) are the best techniques for control.

Red Thread

This is caused by the fungus, Corticum fusiform, usually in the autumn or late summer. it is more noticeable following rainfall or morning dews and is visible as pinkish red patches. Close inspection reveals horn shaped red fungal growths attached to grass blades and stalks sometimes sticking them together since they become gelatinous with moisture. Often damage is minimal, being more unsightly than anything else, and the fungus disappears after several weeks. If there is a severe outbreak then the fungus may remain in drier weather. It often takes hold in soils low in nitrogen and with poor aeration. Aerating the soil and removing thatch therefore helps, as does feeding with a nitrogenous fertiliser. Fungicides containing benomyl, thiophanate-methyl or carbendazim are also beneficial.

Brown Patch

This appears as light yellowing or browning of grass blades in irregular patches.  The areas will increase in size if unchecked and can result in the death of grass and subsequent invasion by mosses.  Lack of aeration, poor drainage, and warm weather are contributors to the infection.  High applications of nitrogen fertilisers in summer make grass more susceptible to attack.

If fertilising you are better to apply a little, more frequently, to reduce likelihood of brown patch.

Hollow tine aeration will help control brown patch.  Chemical control can be achieved with Captan, PMA or Thimer.

Fairy Rings

These appear as a ring of toadstools or puffballs (small round white balls) growing in a circle.  The mycelium of these fungi can penetrate soil to a depth of 8 inches in a mass of white fibres.  This fibrous growth throughout the soil can have a waterproofing effect. Since water does not penetrate, the grass becomes starved for water and suffers.  Aeration can assist in the short term however the only long term sure control is to fumigate the soil (this means killing the turf and starting afresh).

Dollar Spot

Small pale green or yellow spots 1 or 2 inches across appear at first, often with a white edge.  As the disease progresses, spots may grow larger and join to form irregular patches.  The disease occurs most frequently in conditions of high humidity and warm weather.  Overwatering, particularly night watering in hot weather, will favour development of the fungus.  Low nitrogen levels in the soil will favour development of this particular complaint.

Chemical control is achieved with Benlate or Daconil.  You should be sure that Benlate is only from a freshly opened packet since this chemical deteriorates once exposed to air.

Rust

Rust appears as orange, brown or black streaks on leaf blades of grass. Rust is more commonly a problem on greens, particularly in autumn.  Severely infected grass can die.

Some fungicidal sprays may help, however the best control is achieved by removing all grass clippings from the area of the turf and by maintaining a program of regular fertilising and deep watering.