Dicotyledonous weeds terms of control in spring wheat crops

To effectively reduce the number of weeds by herbicidal treatment, both within the time allotted by the application regulations and beyond them, a comprehensive study of the methods and timing of the application of herbicides is necessary. In this connection, three-year studies were carried out in the Altai Region to clarify the optimal timing of the use of herbicides belonging to different classes of chemical compounds against a complex of dicotyledonous weeds in sowing spring wheat. Spraying with herbicides was carried out in 4 terms (beginning of tillering of wheat, end of tillering of wheat, beginning of stemming, end of stemming). In the phase of wheat tubing, high efficiency against dicotyledonous weeds was observed in fluroxypyr (up to 89 %) and tribenuron-methyl (up to 83 %), which contributed to an increase in yield by 56 and 29 %, respectively. Spraying of sowing at the end of tillering was optimal for 2,4-D (ether), the drug helped to reduce weed infestation in this phase by 83 %, which provided an increase in yield by 43 %. Dicamba in the experiment showed itself as a more toxic preparation for spring wheat, therefore, the tillering phase became the optimal period for its use in the experiment, where the effectiveness against weeds was estimated at 69 %, and the increase was 40 % in relation to the control. Late processing times were more effective against perennial weeds, which was due to their biology and the peculiarities of the movement of nutrients along the xylem and phloem.