Dynamics of weed species composition on the example of partial flora of sunflower crops in the steppe zone of Krasnodar region

The article presents information on the dynamics of the species composition of weeds in sunflower crops under long-term research conditions. The phytosanitary role of each species, determined by its activity, was identified at several stages of the study. The difference in the number of active and inactive species indicates the complexity of weed dynamics and the need to take these data into account in agricultural practice. The differences between one-year and multi-year surveys have been established. The importance of long-term observations for an accurate assessment of the species diversity of weeds is emphasized.