LV EN RU DE FR

Pests and Pathogens of Crops

Course developers

Prior knowledge

LauZ5165, Integrated Management of Harmful Organisms

Replaced course

LauZ6137 [GLAU6137] Pests and Pathogens of Crops

Course abstract

Students are introduced with newest achievements, issues and study areas of plant pathology and agricultural entomology. They acquire particular knowledge on systematics, biology and ecology of microorganisms-pathogens and invertebrates. Interactions between plants and pathogens, resistance. Practical acquirements to use identification keys for identification of taxa.

Learning outcomes and their assessment

Students obtain particular knowledge on systematics of microorganisms and invertebrates, understand its relation with biological properties of pathogens and pests and essence of resistance.
Students are able to identify pathogens and invertebrates and to analyse scientific literature to understand interactions between plants and harmful organisms.
Students can integrate knowledge on agricultural entomology and phytopathology with practical plant protection and agronomy. They are competent to give practical advises on identification of plant diseases and pests. Students are able to use scientific methods to study harmful organisms of plants, to prepare presentations and to discuss issues related with plant diseases.

Course Content(Calendar)

1. Introduction. Systematics of invertebrates. 3h
2. Fungi from the phylum Ascomycota as important plant pathogens. Subphylum Saccharomycotina, Taphrinomycotina and Pezizomycotina apakšnodalījumi. 2h
3. Fungi from orders Taphrinales, Eurotiales, Erysiphales, Rhytismatales, Helotiales, Diaporthales, Ophiostomatales, Glomerellales and Dothideomycetes – the most important genera, caused diseases, biological traits of causal agents and their importance in nature. 2h
4. Fungi from the phylum Basidiomycota as important plant pathogens. Exobasidiales, Urocystidales, Ustilaginales and Pucciniales – the most important diseases, their causal agents, symptoms and life cycle. The most important genera from subphylum Agaricomycotina, their importance in nature. 2 h
5. Fungi from the phylums Glomeromycota and Chytridiomycota, the most important diseases, their composition, reproduction, and importance in nature. 1 h
6. Kingdoms Chromista and Protozoa. Composition, reproduction, and importance in nature. Most important diseases caused by these microorganisms. Diseases caused by the order Peronosporales. 2h
7. Identification of plants diseases’ causal agents. 8h
8. Bacteria and viruses as causal agents of diseases, 6 h
9. Basics of interactions between plants and their pathogens in genetic and biochemical level. 2h
10. Nematodes (Nematoda) and other round worms. Gall mites (Eriophydae), spider mites (Tetranychidae) and other chelicerates. 2h
11. Springtails (Collembola). Locusts (Acrididae), mole crickets (Gryllotalpidae) and other orthopterans. 2h
12. Mirid bugs (Miridae), stink bugs (Pentatomidae), jewel bugs (Scutelleridae) and other bugs. Thrips (Thysanoptera). 2h
13. Aphids (Aphididae), wax scales (Coccidae), mealy bugs (Pseudococcidae), cicadas (Auchenorrhyncha), whiteflies (Aleurodidae), leaf flies (Psyllidae) and other homopterous insects. 2h
14. Scarab beetles (Scarabaeidae), click beetles (Elateridae), sap beetles (Nitidulidae), leaf beetles (Chrysomelidae), weevils (Curculionidae), seed weevils (Apionidae), leaf-rolling weevils (Attelabidae) and other beetles. 2h
15. Crane flies (Tipulidae), gall midges (Cecidomyiidae), dark-winged fungus gnats (Sciaridae), leaf-miner flies (Agromyzidae), hoverflies (Syrphidae), frit flies (Chloropidae), fruit flies (Drosophilidae) and other flies. 2h
16. Whites and yellows (Pieridae), hawk moths (Sphingidae), geometer moths (Geometridae), owlet moths (Noctuidae), grass moths (Pyralidae), leafroller moths (Tortricidae), eggars (Lasiocampidae), ermine moths (Yponomeutidae) and other butterflies and moths. 2h
17. Identification of invertebrates’ taxa by using identification keys. 12h

Requirements for awarding credit points

1) Two tests successfully accomplished: identification of invertebrates’ taxa (1) and identification of plant pathogens (2).

2) Final exam (oral) successfully passed.

Description of the organization and tasks of students’ independent work

While working on independent work, students study relevant literature about the themes they have heard in lectures and prepare for successful pass of tests and exam.

Criteria for Evaluating Learning Outcomes

1) Tests on identification of invertebrates and plant pathogens are successfully passed if student correctly identifies more than half of proposed invertebrates (plant pathogens). These tests are not assessed with mark.

2) To pass the oral exam, student must answer to two questions: question on harmful microorganisms for cultivated plants (1), question on potentially harmful group of invertebrates for cultivated plants (2). All questions are announced to students at least four weeks before the exam. At the beginning of the exam, student randomly picks both questions. 15–20 minutes are given to prepare answers. Then student must answer to question by describing systematic, morphological, biological and ecological properties and potential harmfulness of corresponding groups of microorganisms and invertebrates. Base mark of the exam is 8. Student may earn this mark if his/her knowledge corresponds to amount of information obtained during lessons. If answer to the questions are incomplete, then the mark of exam decreases. Student may earn higher mark (9 or 10) by demonstrating deeper knowledge obtain from scientific literature during independent studies.

Compulsory reading

1. Tronsmo A.M., Collinge D.B., Djurle A., Munk L., Yuen J., Tronsmo A. Plant Pathology and Plant Diseases. CABI: 2020. 437 p. Ir LLU AAZI 1 eks.
2. Gillot C. (2005). Entomology. Dordrecht: Springer. 831 p.

3. Ozols E. (1973). Lauksaimniecības entomoloģija. Rīga: Zvaigzne. 495 lpp.

Further reading

1. Agrios G.N. Plant Pathology. – Academic Press, INC.-1997 un visi vēlākie izdevumi.
2. Engemann J.G., Hegner R.W. (1981). Invertebrate zoology. New York; London: Macmillan Publishing Co. 746 p.
3. Fungal Plant Pathogens (2012), ed. By C.R. Lane, P.A. Beales, K.J.D. Hugges. CABI. 307 p.
4. Molecular Plant Pathology: Annual Plant Reviews (2000), Vol. 4, ed. By M. Dickinson and J. Beynon, Sheffield Academic Press. 293 p.

5. Schumann G.L. Plant diseases: Their Biology and Social Impact (2003). APPS PRESS, 397 p.

Periodicals and other sources

1. Canadian Journal of Plant Pathology. [tiešsaiste]. Published behalf of Canadian Phytopathological Society. [Skatīts 08.03.2019]. Piejams: https://www.tandfonline.com/toc/tcjp20/current
2. Journal of Plant Pathology. [tiešsaiste]. Springer. Online ISSN: 2239-7266 [Skatīts 08.03.2019]. Pieejams: www.springer.com/life+sciences/biochemistry+%26+biophysics/journal/42161
3. Journal of Applied Ecology. [tiešsaiste]. British Ecological Society. Online ISSN: 1365-2664. [Skatīts 23.02.2019.]. Pieejams: https://besjournals.onlinelibrary.wiley.com/journal/13652664
4. Journal of Applied Entomology. [tiešsaiste]. Blackwell Verlag GmbH. Online ISSN:1439-0418. [Skatīts 01.03.2019.]. Pieejams: https://onlinelibrary.wiley.com/journal/14390418

5. Crop protection. [tiešsaiste]. The Official Journal of the International Association for the Plant Protection Sciences. ISSN: 0261-2194. [Skatīts 01.03.2019.]. Pieejams: https://www.journals.elsevier.com/crop-protection

Notes

Master study programme “Agriculture”