BIOLOGY AND CONTROL OF ANOTHER IMPORTANT WEEDS OF THE CZECH REPUBLIC: CANADIAN FLEABANE - CONYZA CANADENSIS (L.) CRONQUIST

Conyza canadensis grows well especially on light soils and dry locations. It reproduces only generativelly. Rippened achenes show good germination rates. Conyza achenes are positivelly photoblastic and can germinate also under conditions of higher salinity and low water availability. Plants emerge from soil surface and upper soil layers only. Individuals that emerged during spring finish their life cycle in the same year white those that emerge during autumn mostly overwinter in growth stage of leaf rosette and continue in growth in spring. C. canadensis is relatively susceptible to majority of: herbicide active ingrediences and so it is not a problematic need on arable land. Pupolations resistant to triazine herbicides and to glyphosate can he found in many countries.