Weed control chemical methods system in sunflower crops

The goal of the research was to determine the effects of various chemical control systems on the degree of weed infestation of crops, the growth of cultivated plants and the yield of sunflower seeds. The herbicides Triflyurex, Express, Selector and their combination in sunflower crops in the Lugansk and Rostov regions were the objects of the research. The soil was ordinary chernozem. Hybrid HC-X-6006 (Serbia) was sown. By the stage of formation of 2-4 leaves in sunflower, there were 384 weed seedlings / m2 in the crops. The use of the soil herbicide Triflurex alone did not provide sufficient level of weed control. The use of the system of soil andpost-emergent herbicides ensured the control of 80.4-81.3 % of weeds. The application of the herbicide Express against dicotyledonous weeds in the phase of 3-4 pairs of true leaves in combination with the Selector preparation against monocotyledonous species ensured the destruction of 89.2 % of weeds. With the introduction of half the norm of the same preparations in the phase of 2 pairs of true leaves in sunflower, and the second half in the phase of 3-4 pairs of leaves, the weed infestation decreased by 95.0 % in terms of the number of weeds, and in weight - by 97.1 %. The maximum yield of sunflower seeds, 3.41-3.45 t/hectare, was obtained with the use of post-emergence herbicides with their single or double application in half doses. Thus, the most reliable, low-toxic for sunflower and ecologically safe system of protection of sunflower plants is a two-fold application of the herbicide Express and Selector at half rates in the phase of 2 and 3-4 pairs of leaves in cultivated plants.