The purpose of the course is to introduce students to basic knowledge of biology and ecology of weeds, invasive and parasitic plants. Particular emphasis is given on the principles of integrated weed management using cultural, biological, natural and chemical methods . In addition, the interactions of weeds with crops are studied (competition / allelopathy). Moreover, herbicides are presented (groups, mechanisms of action, selectivity, fate and behaviour in soil, movement in the plant, metabolism) and the advantages and disadvantages of chemical and non-chemical methods of weed control are also discussed. Special reference is made to the problem of herbicide resistant weeds (and methods of prevention and management) and to the ways of correct application of herbicides.