18459 - Protection of Food Crops ( Corso Integrato) - Postharvest Pathology of Food Crops

Learning outcomes

This course trains students to:

at the end of the course the student will know a)  the phytopathogens agents of postharvest losses in food products; b) understand the role of integrated protection in the prevention of postharvest losses; c) evaluate the effects of pathogens attacks on the quality and on the contamination, by toxic compounds, of food products.

Course contents

POSTHARVEST PATHOLOGY

GENERAL ASPECTS (Teaching units:10)

Chilling injury (teaching units:3)

importance and limits to the use of cold chain, classification of horticultural products according to their susceptibility to chilling injury, symptoms, induced structural and physiological modifications, control.

Integrated protection of plant products (Teaching units 7)

Integrated postharvest disease management of raw and semi-processed fresh products, during storage, transportation and distribution (physical, chemical and biological methods).

Physical methods

High temperatures: types of heat treatments (hot air and hot water), effects on the host and on the pathogen.

Low temperature (cooling): importance of the cold chain in the storage and distribution of raw and semi-processed fresh plant products, effects on the host and on the pathogen.

Oxygen and carbon dioxide: importance of controlled atmosphere (CA) , dynamic CA and modified atmosphere in storage and distribution of raw and processed fresh plant products, effects on the host and on the pathogen.

Ethylene scrubbing: influence of ethylene on ripening and senescence of the products, scrubbing technologies, effects on the host and on the pathogen.

Relative humidity (RH): importance and management of RH during storage and distribution, effects on the host and on the pathogen.

Ultraviolet light at low doses: management of the treatments, effects on the host and on the pathogen.

Ionizing radiation: sources, safety, limits, effects on the host and on the pathogen.

Chemical methods

Disinfectants: importance, types of disinfectants used on fresh plant products, how to apply, efficacy.

Chemical protectants: classification, hazard classes, technical limits, safety precautions, mode of application and of action, formulation types, residues, outlook of EC regulation of pesticide residues.

Biological methods

Natural susbstances: sources, activity, non target effects, application limits.

Antagonistic microrganisms (fungi, bacteria and yeasts): mode of action, compatibilty with other control methods, formulations, efficacy limits.

SPECIFIC PRODUCT DISESASES AND DISORDERS (Teaching units 16)

Each disease and disorder is described from the point of view of:

• importance, distribution, qualitative and quantitative losses caused
• taxonomy, symptomatology, epidemiology and control
• influence on product processing (losses, mycotoxins, safety issues)

Pome fruits: Neofabrea, Penicillium, Botrytis, Mucor, Alternaria, superficial scald, soft scald, watercore, bitter pit. Stone fruits: Monilinia, Botrytis*, Rhizopus, Mucor*, internal breakdown (mealiness), abnormal ripening. Kiwifruit: Botrytis*, Phialophora. Grapes: Botrytis*, Aspergillus*. Strawberry: Botrytis*, Colletotricum. Tomato: Alternaria*, Colletotricum*, Botrytis* (mold count by Howard method), Pectobacterium, chilling injury. Potato: Fusarium, Pectobacterium*, greening, sweetening, sprouting.Onion: Botrytis*, Aspergillus*, Colletotricum*, Fusarium*, Pectobacterium*, Pseudomonas, sprouting. Leafy vegetables: Sclerotinia, Botrytis*, Pectobacterium*, Pseudomonas*, russet spotting, yellowing, senescence.

* Only symptoms and control

Readings/Bibliography

Postharvest pathology

Patologia postraccolta dei prodotti vegetali
di V. De Cicco - P. Bertolini - M.G. Salerno Pagg.287, Euro 35,00 (l'importo dei diritti d'autore è devoluto alla Società Italiana di Patologia vegetale - SIPaV) - Piccin Nuova Libraria S.p.A., Padova. Italy

Atlas:

Snowdon A.L. A colour atlas of postharvest diseases & disorders of fruit & vegetables. Vol. 1 & 2 . Wolfe Scientific ed. London, 1990.

Website : http://books.google.com/books?id=WK-Scwl9skYC&pg=PA184&lpg=PA184&dq=pseudomonas+fluorescens+vegetables+rot&source=bl&ots=wSGByFca5i&sig=PLTrtJYPNRoAj-NTMIliB1-Zlzk&hl=en&ei=ZoGAToTiOKXH0QXwivnBCQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEMQ6AEwBQ#v=onepage&q=pseudomonas%20fluorescens%20vegetables%20rot&f=false

Tonini G. Atlante delle alterazioni microrganiche postraccolta (pomacee e drupacee). Bayer s.p.a, Milano,1996, Italy.

Web sites:

[http://postharvest.ucdavis.edu/PF/] → Produce facts →Choose the language (English, Francais, Espanol) → fruits /vegetables species → Link to produce photo album (miglior sito web)

AAVV. Identifying and Controlling Postharvest Tomato Diseases in Florida - http://edis.ifas.ufl.edu/

AAVV Market Diseases of Apples, Pears, and Quinces. http://postharvest.tfrec.wsu.edu/market_diseases.html#breakdown

C. L. Xiao. Postharvest Diseases of Apples and Pears - A Guide to Diagnosis and Control. http://decay.tfrec.wsu.edu/

AAVV. The Commercial Storage of Fruits, Vegetables. http://www.ba.ars.usda.gov/hb66/contents.html

Teaching methods

The course will offer traditional oral classroom teaching methods with PowerPoint presentations (the same files that students will find in PDF format on the VIRTUALE portal). During these sessions, the lecturer will actively engage with students in discussing the lesson content, presenting case studies, practical examples, and showing technical videos relevant to the topics covered.

Lectures will be complemented by practical exercises involving the identification of postharvest diseases in fruits and vegetables, with the participation of experts from companies for discussing about postharvest preservation and storage.

Students are encouraged to take an active role in the lessons by presenting in class problems discussed in scientific articles proposed by the lecturer and related to the subject matter.

 

Assessment methods

The exam is unique for both modules and includes a written and an oral part.

The written part consists of a multiple-choice test with 4 possible answers, only one of which is correct. There are 26 questions in total (13 from the pathology module and 13 from the parasitology module). Each correct answer is worth 1 point, and there are no penalties for unanswered or incorrect answers. The time allowed is 40 minutes. The exam is usually held (depending on availability) on the computers in the IT classroom, or alternatively in a different classroom (announced on the Almaesami website) in paper format. The test is corrected immediately afterwards. Students are admitted to the oral exam if they pass the written test with a score of at least 16 points (with at least 8 correct answers in each module). The oral exam is worth 4 points (2 points for each module) and consists of identifying postharvest diseases or parasites.

Students with specific learning disabilities (DSA) are kindly asked to notify both the lecturer and the Unibo DSA office at least one week in advance if they require any accommodations

Registration on Almaesami is mandatory; the exam registration list will open at least 10 days before the exam date and will close two days prior to the exam. If a student decides not to take the exam on the booked date, it is mandatory to remove their name from the list before the registration deadline.

The course, teaching materials, and written exam questions will be in Italian. Erasmus students may answer the written exam questions in English.

 

Teaching tools

PC, projector, diseased products, study visit to wholesale market.

Office hours

See the website of Elena Baraldi