Hermes herbicide application in sunflower cultivation
Experimental data of scientific research obtained in ARI of the South-East region has shown the possibility of increasing the sunflower productivity depending on the application timing of the modern domestic Hermes herbicide 1.0 l/ha. Its effect on the phytosanitary state of sowing and crop productivity in the conditions of the Lower Volga region has been studied for three years (2014-2016). The highest results in the fight against weed plants in sunflower were obtained when it was treated in phase of 2 and 4 leaves. The number of weed plants was 15-28 times less in the experimental variants than in the control ones including perennial by 6-7.5 times, annual by 15-29 times, that is, biological effectiveness against annual weeds was 93.4-96.6 %, perennial 83.8-87.1 %, and all weed plants 93.3-96.5 %. The herbicide was highly effective throughout the growing season. Before harvesting, the overall weed infestation decreased by 89.0-92.7 %, and the weight of weed plants reduced to 93.3-96.5 % when applying the herbicide. The efficiency was lower when the crops were treated in later phases of 6, 8 or 10 leaves. So the application of the herbicide in the 6-leaves phase reduced the weed infestation by 90.1 %; in the 8-leaves phase by 84.1 %; in the 10-leaves phase by 72.4 %. When agrotechnical techniques (2 cultivations) are used, it decreased only by 30.0 %. The use of Hermes herbicide contributed to a significant increase in the crop productivity. The best results for increasing the productivity were obtained when the herbicide was applied in the 4-leaves phase (0.84 t/ha (55.6 %)). When applying the herbicide in the 2-leaves phase, the result was slightly less (0.73 t/ha (48.3 %)). Its use in the 6-leaves phase contributed to the crop preservation (0.68 t/ha (45.1 %)); in the 8-leaves phase (0.56 t/ha (37.1 %)); in the 10-leaves phase (0.49 t/ha (32.5 %)). The smallest increments (0.25 t/ha) were due to the use of two cultivations with the crop productivity at the control 1.51 t/ha