Course code LauZ5125

Credit points 5

Weed Science I

Total Hours in Course200

Number of hours for lectures32

Number of hours for seminars and practical classes32

Number of hours for laboratory classes16

Independent study hours120

Date of course confirmation22.03.2011

Responsible UnitInstitute of Soil and Plant Science

Course developers

author Augsnes un augu zinātņu institūts

Maija Ausmane

Dr. agr.

author Augsnes un augu zinātņu institūts

Dainis Lapiņš

Dr. agr.

Course abstract

MStudents of master studies become more profound to biological properties of weeds species diversity. Obtain the knowdedge about the plant life-relating factors, prognosis of changes by modelling Technologies of crop production. Evolution of weed control. Using of biological individuality of weeds for weed control. Weeds in the agrophytcenosis. Valuation criteria of agroeconomical efficiency of weed control, different weed control technologies.

Learning outcomes and their assessment

1. Students obtain the more profound knowledge about scientific basics of weed biology, species diversity, weed control. Students to knew put into praktice the biological properties of weeds for weed control.
2. Students acquire skills to aplied and compare different criteria of valuation of economical efficiency of weed contro, different weed control technologies.

3. In the result students are competent to direct production or advisory work, to carry out investigations self-dependently, employing knowledge in weed biology and control, to study and analysis scientific publications.

Course Content(Calendar)

1. Cours Structure, Expection, Assignments.
2. Concepts of Weed science. Definitions of weeds.
Weed biology and ecology
3. Relevance of weeds in agrocenosis
4. Classification of weeds: botanical, biological
5. Population of weeds:dispersal, community, dominants
6. Characteristic of weeds: biomes
7. Weeds as environmental indicator species
The Test 1 (2 – 7 p.)

8. Weed life cycles and reproductive biology: asexual, sexual reproduction. Relevance of weed management systems.
9. Seed dormancy, and longevity. Periodicity of seed dormancy.
10. Germination requirements.
11. Seed bancs. Reproduction from vegetative parts.
12. Succession.
13. Invasive weed species, alien invaders, environmental implications.
14. Problems from introduced plants.
15. Ecological relationships and concepts: principles of competition. Factors influencing competitiveness.
16. Allelopathy. Allelopathy in weed management.
17. Weed conception and their noxiousness, the threthold of noxiousness.
18. Characteristics of soil and crop weediness in Latvia
19. Benefical importance of weeds
The Test 2 (8 – 19 p.)

Weed control
20. Principles in weed management: direct and indirect.
21. Direct weed control – mechanical, chemical, biological.
22. Mechanical weed control: principles, methods.
23. Influence of conventional soil tillage systems on weed population
24. Influence of reduced soil tillage systems on weed population
25. Chemical weed control: principles, use of herbicides.
26. Effect of chemical weed control
27. Weed selectivity to herbicides.
28. Biological weed control: biotic aģents in weed management.
29. Indirect weed control: preventation, crop sequence.
30. Influence of crop rotation and crop sequence in weed management.
31. Integrated weed control systems
32. Weed management strategies in biological farming systems
The Test 3 (20 – 32 p.)

Practical works/ seminars
1. Analytical estimation of crop weediness.- 2 h
2. The models of economical threshols of different weed groups.- 2 h
3. The effectiviness of agroeconomical criteria of weed control estimation .- 2 h
4. Micoherbicides.
5. Weeds – environmental indicators. Weed communities. - 4 h
6. Characteristics of soil and crop weediness. – 2 h
7. Seminar. Crop weediness of field crops in Latvia. .- 2 h
8. The potential – 2 h
9. The investigation methods of weed population = 2 h
10. The monitoring of crop weediness in different reģions of Latvia. – 2 h
11. Historical background of herbicide synthesis and use – 2 h
12. Nowaday weed chemical control systems – 2 h
13. Development of weed control in future = 2 h
14. Investigations of allelotathycal effects on weed interference with desired plants.- 2 h
15. Seminar.Integrated weed management systems.- 2 h

Laboratory works
1. Identification of weed seeds in soil and crop yield – 4 h
2. Database of weeds - 2 h
3. Identification of weed seedlings – 2 h
4. Crop Weediness anlalyses by counting method– 2 h
5. Weed control integrated system in rape and field beens - 2 h

6. Weed control integrated system in cereals.- 2 h

Requirements for awarding credit points

The writen examination.
The assignment for the test include:
- theoretical questions covered during the semester.
All tests and tutorials of laboratory works should have a positive evaluation.

Before to pass an exsamination must be presented report.

Criteria for Evaluating Learning Outcomes

The assessment of thre study course examination is comulative. It is made up of the grades of the examinationtests during the semester and tutorials of laboratory works.
The grade is successful if at least 50% of the question of tests or the examination are correct.

Students who have at least „7”are not required to write a theoretical part of the examination; their grade for this part is made up of an arithmetic mean of grades in tests during the semester and grade of tutorials of laboratory works.

Compulsory reading

1. Hock B., Fedtke C., Schmidt R. R. (1995) Herbicide / Entwicklung, Anwendung, Wirkungen, Nebenwirkungen . -Stuttgart.New York, Georg Thieme Verlag, 358 s.
2. Hanus H., Heyland k. - U., Keller E. (1997) Grundlagen des Pflanzenbaues 800 s.
3. Aldrich R.J. and Kremer R.J. Principles in Weed Management (1997) Iowa State University Press.. - 425 p.
4. Weed Control Handbook: Principles (1990) / Ed. by R.J. Hance and K. Holly. - Blackwell Scientific Publications, Oxford,. - 553 p.
5. Turka I. Pesticīdu lietošanas riski augu aizsardzībā (2003) – Rīga: LR ZM,.-159 lpp.
6. Lapiņš D., Kažotnieks J. (2000) Laukkopība.- Ozolnieki, LLKC, 247 lpp.
7. Weed Research. Expanding Horizons. Edited by Hatcher P.E., Fround-Williams R.J .Willey. 2017. 432 p.
8. Radosevich S., Holt J., Ghersa C. Weed Ecolgy: Implications for Management.John Wiley and Sons. Inc.,1997. 589 p.

9. Handbook of Weed Management Systems. Edited by Albert E. Smith. Marcel Dekker, Inc. 1995. 741 p.

Further reading

1. Hant M. The Arable Weeds of Europe. (1983) BASF U.K., - 494 p.
2. Nezāļu, to grupu un augu aizsardzības tehnikas terminoloģijas vārdnīca(1997). /sast. A. Lejiņš u.c. - Skrīveri,. - 300 s.
3. Weed Control in Baltic Region. (1997) Proceedings of International Conference. Latvia University of Agriculture, Jelgava, - 259 p.
4. Weed Control in the Changing Situation of Farming in the Baltic Region (1995). // Proceedings of International Conference. Lithuania - Kaunas, - 340 p.
5. Фисюнов А.В.( 1984) Сорные растения. Москва: Колос, - 317 с.
6. Hakansson S. Weeds and Weed Management on Arable Land : An Ecological Approach. CABI Publishing. 2003. 288 p.

7. Modern Crop Protection Compounds. Vol. 1: Herbicides. Edited by W. Kramer, U. Schirmer, P. Jaschke, and M. Witschel. Willey VCH Verlag GmbH & Co. KcaA. 2012. 534 p..

Periodicals and other sources

1. Agro Tops.
2. Saimnieks LV.

3. Weed Research. An International Journal of Weed Biology, Ecology and Vegetation Management. European Weed Research Society (EWRS). Wiley Online Library. https://online