Influence of soil herbicides on biometric indicators and yield of sunflower

The article has presented the results of field experiments and laboratory studies of the effectiveness of the use of soil herbicides of various chemical classes in sunflower agrophytocenosis. The effectiveness of the influence of the specified technological aspects on the processes of growth and development, as well as on the formation of quantitative and qualitative indicators of the sunflower harvest, has been established. The research results have confirmed more optimal conditions for the formation of vegetation mass, assimilation apparatus and the root system of sunflower against the background of the application of pre-emergence herbicides. For example, the height of the plants was greater by 2.9–4.5 cm, the length of the root system exceeded the benchmark by 6.1–10.0 cm, the area of the leaf surface — by 1.4–2.8 dm2. When determining such a fundamentally economic and valuable indicator, as seed roughness, а clear regularity of the effect of the use of soil herbicides on this indicator has not been found. The study of the influence of Harness, Dual Gold and Gezagard on the quality indicators of sunflower seeds has showed that the use of herbicides had had a positive effect on the process of oil accumulation. In addition to quality indicators, sunflower yield has been also determined. The yield of the sunflower hybrid Sonachny was 2.64 t/ha when using the herbicide Gezagard, while the yield in the control was 2.13 t/ha. Under the action of Harness and Dual Gold herbicides, the yield was at the level of 2.46–2.47 t/ha, which is 15.5% higher than the control.