27342 - Plant Pathology and Pathometry

Academic Year 2021/2022

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: First cycle degree programme (L) in Marketing and Economics of the agro-industrial system (cod. 8526)

Learning outcomes

Students will acquire knowledge on: 1) the general bases of plant diseases caused by biotic and abiotic agents; 2) major infective crop diseases with severe economic impact; 3) the measurement of disease symptoms; 4) principle of disease control in according to the recent legislation of integrated or biological disease management.

Course contents

A) Prerequisites

Students attending this course will have good knowledge of plant biology physiology, agricultural genetic and microbiology. Such skills are provided by the courses of the first and second years.

B) Teaching Units

  1. General plant pathology
  2. Diagnosis and plant disease measurement
  3. Principles of disease control
  4. Specific plant diseases and their control

1. General plant pathology (total teaching unit 14 hours)

Introduction to plant pathology (2 hours) - Disease definition and the concept of plant disease. Differences between disease and damage. Economic and social importance of plant disease. Infectious and non-infectious diseases. Differences between symptom and sign of disease. Morphological and physiological alterations.

Symptoms (1 hour) – Localized and systemic, specific and non-specific, internal and external. Types of symptoms: discolouration, changes in size and shape, necrosis, stunting, hyperplasia, hypertrophy.

Disease classification (1 hour) – Etiological criterion: biotic and abiotic diseases. Pathophysiological criterion: epiphytic, trophic, necrotic, auxonic, vascular, lytic and wood diseases.

Pathogenesis (2 hours) – Biotic disease cycle: inoculation, spore germination, infection (penetration, colonisation, symptom appearance, spore production) dispersal of inoculum, winter survival. Monocyclic and polycyclic diseases. Endemic and epidemic diseases.

Pathogens (5 hours) - Morphological, biochemical and biological features of fungi, oomycetes, bacteria, phytoplasmas and viruses. Biotrophic and necrotrophic pathogens.

Phytosanitary surveillance (1 hour) - Aims, quarantine pathogens, measures to prevent and limit their spread, role of International Plant Protection convention (IPPC), Regional Plant Protection Organizations (RPPOs), European and Mediterranean Plant Protection Organization (EPPO), Italian Phytosanitary Service, phytosanitary certificate for the export, EC Plant Passport, example of Erwinia amylovora as a quarantine pathogen and regulated areas subjected to its surveillance. The concept of the phytosanitary trade barrier.

Plant (host)-pathogen interaction (2 hours) - Non-host plant, incompatibility or host resistance, compatibility. How plants defend themselves against pathogens (pre-existing and induced defences).

Knowledge acquired in the teaching unit 1:

Specific terms to use in plant disease description.

Different type of plant pathogens and main characteristics.

Main diseases and abtiotic alterations.

Disease cycle phases in relation to the pathogen, the environmental factors and vegetative plant phases.

Plant-pathogen interaction

2. Diagnosis and plant disease measurement (total teaching unit 4 hours)

Diagnosis (1 hour) - Visual analysis of symptom appearance on plant and on crop in the field. Gathering of information of agronomic and climatic conditions during crop cultivation. Collection of symptomatic samples. Observation of samples. Koch's postulates.

Disease measurement (3 hours) - Methods of disease assessment. Incidence, severity and economic threshold of the disease. Disease indexes. EPPO standards. Examples of disease severity index values for vineyard downy mildew and for fungal diseases of cereals.

Knowledge acquired in the teaching unit 2:

Elements of diagnosis

Usefulness of plant disease assessment.

Calculation of disease incidence and severity.

3. Principles of disease control (total teaching unit 11 hours)

Fundamental concepts (1 hour) – Importance of plant disease control in relation to economic and environmental sustainability and to healthy crops. Possibility to reduce disease severity by action on the pathogen, the environment and on the plant. Fundamental guidelines of integrated disease management. Principles of compulsory and voluntary integrated disease control.

Cultural practices to prevent diseases (2 hours) - Crop rotation, tillage, fertilization, irrigation, selection of the cultivar(s) and site of cultivation, plant and soil management, pruning. Methods to prevent the spreading of soil-pathogens.

Phytosanitary products (2 hours) – Meaning of the term "phytosanitary product". Short background on the law rules of plant protection products (Reg. CE n.1107/2009, Dir. CE n. 128/2009, D.Lgs. n. 150-14/08/2012, Reg. CE n. 396/2005). About the National Action Plan (PAN) for the sustainable use of phytosanitary products. Toxicological classification of substances (CLP Reg. CE n. 1272/2008). Label and formulation of products.

Characteristics of fungicides (1 hour) – Specific terms to use in plant disease control. Contact, systemic, protective, curative and eradicant fungicides. Modes and mechanisms of action. Pre-harvest interval (latest time of application) and time to re-entry in the field. Maximum level of residue. Resistance of pathogens to fungicides.

Synthetic and natural fungicides (3 hours)

Main groups, spectrum of activity and mechanism of action

- Inorganics: copper, sulphur and carbonates;

- Synthetic organics: dithiocarbamates, phtalimides, BSI, QI, SDHI, anilinopyrimidines, CAA, fenilamides, acetamides, and phosphonates;

- Plant, algae and crostaceous derived products;

- Microorganisms.

Other control means (1 hour) – Termotherapy, steam soil treatment, solarisation and soil biofumigation.

Summary of disease control peculiarity against fungi, oomycetes, bacteria, phytoplasma and viruses (1 hour)

Knowledge acquired in the teaching unit 3:

Principles of plant disease control.

Different control methods.

Knowledge of law rules on plant protection products.

Principles of integrated and biological disease managements.

4. Specific plant diseases and their control (total teaching unit 7 hours)

This part develops main diseases of important crops, their symptoms, epidemiology and basic elements of control measures.

Grapevine (2 hours) - Downy mildew (Plasmopara viticola), grey mould (Botryotinia fuckeliana, an. Botrytis cinerea), powdery mildew (Uncinula necator, an. Oidium tuckeri), yellows disease by phytoplasmas.

Pome fruits (2 hours) - Apple scab (Venturia inaequalis, an. Spilocaea pomi), apple powdery mildew (Podosphaera leucotricha, an. Oidium farinosum), fire blight (Erwinia amylovora), Apple Proliferation Phytoplasma (APP)

Stone fruits (1 hours) - Peach leaf curl (Taphrina deformans), twig cankers (Fusicoccum amygdali, syn. Phomopsis amygdali), brown rot (Monilinia spp., an. Monilia), Olive Quick Decline Syndrome (Xylella fastidiosa), sharka (PPV - plum pox virus).

Kiwifruit (0.5 hours) - Bacterial canker (PSA - Pseudomonas syringae pv. actinidiae

Herbaceous crops (1 hour) - Potato and tomato late blight (Phytophthora infestans), tracheomycosis (Fusarium oxysporum f.sp.), tomato spotted wilt virus (TSWV), Fusarium head blight (Fusarium spp.), wheat foot rot (Gaeumannomyces graminis tritici, Rhizoctonia cerealis, Pseudocercosporella herpotrichoides), rusts (Puccinia spp.), powdery mildew (Erysiphe graminis f. sp. tritici), Septoria tritici blotch and soil borne cereal mosaic virus (SBCMV)

Cankers (caused by bacteria and fungi) and wood decay (caused by fungi) and Armillaria root rot (Armillaria mellea, sin. Armillariella mellea) (0.5 hour)

Knowledge acquired in the teaching unit 4:

Symptoms of the main diseases and abiotic stresses of agricultural plants mainly.

Disease epidemiology.

Disease control measures.

Teaching support activity (24 hours)

Activity in lecture rooms

1) Training seminars on

- Cereal diseases and their control: Fusarium head blight (Fusarium spp.), foot rot (Gaeumannomyces graminis tritici, Rhizoctonia cerealis, Pseudocercosporella herpotrichoides), rusts (Puccinia spp.), powdery mildew (Erysiphe graminis f. sp. tritici) and Septoria tritici blotch.

- Abiotic stresses and damage by the hail quantification

- Mycotoxins in food

2) Projection of educational movies on fungus and disease cycles.

3) Plant samples showing disease symptoms.

4) Assessment of disease severity by using specific scales.

5) Reading and discussion of fungicide product labels and safety sheet.

Laboratory activity

1) Fungal pathogens recognition at optical microscope.

2) Assess of fungicide database for disease control strategies.

3) At the end of the activity, students will be invited to write a brief report.

Field activity

1) Assessment of disease symptoms at the agricultural garden of the Dipsa, at the University experimental farm in Cadriano (BO) and at other farms.

Consolidation activity

This part of the course will be dedicated to the consolidation of the knowledge provided during the lessons, with particular attention to the needings raised by the students.

Readings/Bibliography

  • Vannacci G. et al. (2021). Patologia vegetale, Edises, ISBN: 8836230415
  • Belli G. (2012). Elementi di Patologia Vegetale, Piccin Editore, ISBN: 8829921297.
  • Agrios G.N. (2005) Plant Pathology, Academic Press (USA), ISBN: 9780120445653 - This textbook is usefull for students who wish to make the exam in English.
  • Lorenzini G. & Nali C. ‘Principi di Fitoiatria’, 2012, Edagricole Bologna, ISBN: 8850653883.

Teaching material will be upload in the "Isegnamenti on line" at the end of each lesson. Students of this course should register to the plattform to download the teaching material.

Teaching methods

1) Class lectures

Knowledge acquirement a) necessary to understand the general characteristics of fungi, bacteria, viruses and phytoplasmas pathogens of agricultural and ornamental plants; b) principles of integrated and biological disease control; c) of the methods to measure plant diseases; d) on the main abiotic stresses.

This knowledge will be monitored during the course through a continuous interaction between teacher and student. This will possibly involve also the discussion of some interesting papers on the main topics covered during the lessons. This will allow to stimulate the critical sense communication skills of the student.

2) Practical activity

Learning of: a) observation and assessment of disease symptoms; b) general practices commonly used in a laboratory of plant pathology and crop protection; c) consultation of databases ad web sites to plan disease managements and to learn the key aspects of plant protection products, in order to practically apply the theoretical knowledge acquired during lessons.

3) Guided tours

Student will be accompanied in guided tours to the agricultural field of University, in Cadriano (BO) and in local farms in order to examine plant diseases symptoms.

· Class lectures: through the class lectures the student will acquire the knowledge necessary to understand the general characters of plant pathogens and the resistance forms of plants. This knowledge will be monitored during the course through a continuous interaction between teacher and student. This will possibly involve also the discussion of some interesting papers on the main topics covered during the lessons. This will allow to stimulate the critical sense communication skills of the student.

· Practical activity: the student will be directly involved in general practices commonly used in a laboratory of plant pathology in order to practically apply the theoretical knowledge acquired during lessons.

· Guided tours: student will be accompanied in guided tours to the agricultural field of DipSA, in Cadriano and in local farms in order to examine plant diseases symptoms.

Assessment methods

Written exams in Italian language. Written exams in English upon prior and reasoned request. Esams will cover all the issues raised in the lessons and in training seminars. In particular the exams will take place in June (two exams) in July (two exams), in September (two exams), in December (one exam) and in January (two exams) and in February (one exam). Exam dates will be listed in "Alma esami" and in the hompage of the teacher in the "latest news" section. The exam consists of 31 closed questions. Each question will have 4 answers with only one is right. Exams will take place on line.

For the preparation of the exam, self-tests are provided tests for each topic covered in the lessons. Self-tests will be available on IOL (Insegnamenti On Line). These are multiple choice quizzes with four answer options, of which only one is correct. Each correct answer has a value of 1.0 point. Quizzes are not required to take the exam, but they are recommended. Each quiz can be run only once and has a time limit hat can be different depending on the number of questions. There is a final score (1 or 2 points) that will be added to that of the final official exam under the following conditions: a) it is necessary to perform all the self-tests; b) those who have run all the self-tests with a score in each from 60% to 80% of exact answers will have 1 point; c) those who have run all the self-tests with a score higher than 80% of exact answers will have 2 points. There are no penalties for those who do not respond accurately according to the limits set out above, partially perform the self-tests or do not perform them at all. During the period of the teaching lessons, the self-tests will be active until June 1 th 2021. Then, the self-tests will be available in a period ranging from the end of each exam to 4-5 days from the beginning of the next one.

Teaching tools

Overhead projector and personal computer will be used for class lectures.

Laboratory exercises will take place in the Teaching laboratories of

  • Biology I - 1st floor – North Wing, n. 46.
  • ICT and multimedia – 1st floor – North Wing, n. 44-46.

Office hours

See the website of Roberta Roberti

SDGs

Zero hunger Good health and well-being Responsible consumption and production

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.