摘要：From the point of view of herbicide efficacy, the most important target enzymes in amino acid biosynthesis processes are glutamine synthetase (GS), enolpyruvylshikimate-3-phosphate synthase (EPSP), and acetolactate synthase (ALS). Among GS inhibiting herbicides, active ingredience glufosinate is widely used. It is a non-selective post-emergent herbicide or desiccant which is uptaken by plants by green parts only. This active ingredience is poorly translocated to longer distances in plant body but it shows locally systemic activity so its efficacy is high also in the case of later growth stages of weeds. Higher and faster efficacy can be reached under conditions of higher intensity of sunlight, high air and soil moisture and high temperature. EPSP inhibitors are easily dissociated salts of glyphosate. In relation to its rapid decomposition in the soil, glyphosate is uptaken by leaves only. It is relatively well and rapidly translocated by the plant. Glyphosate shows the highest translocation rate when weeds are treated during the period of intensive growth. Even if the affected plants stop their growth immediately after application, chlorosis and willing occur after several days. Plant tissues necrotise and subsequently die after 1–3 weeks. Some species can show anthocyanin coloration of the leaves
关键词：herbicide mode of action; herbicide site of action; glufosinate NH4; glyphosate; sugar beet; phytotoxicity
