The dissertation highlights the peculiarities of growth and development and the formation of productivity of dyeing safflower varieties Dobrynya and Sonyachny under the influence of changes in the elements of cultivation technology: the width of the rows and the density of crops in the conditions of the Right Bank Forest Steppe of Ukraine.
It was established that the shortest duration of vegetation was obtained by growing the Dobrynya or Sonyachny varieties with a row width of 19 cm and sowing rates of 100–200 thousand pieces/ha. At the same time, the increase in the sowing rate even up to 300,000 units/ha contributed to an increase in the duration of the growing season by 2–4 days. In general, for the extension of the duration of individual phenophases when growing with a row width of 57 cm and a density of crops of 200–300 thousand units/ha, these options also resulted in a longer period of general vegetation.
It was investigated that the density of crops at the time of full emergence differed from the planned one, but was within the limits of permissible deviations of ±10 %.
It was determined that the density of crops at the time of harvesting of safflower reflected the loss of vegetation during the growing season, and therefore, in general, for the Dobrynya variety, they amounted to 10.9 thousand units/ha, and for the Sonyachny variety – 11.3 thousand units/ha, compared with accounting for the time of full stairs. Also, with a row spacing of 19 cm, the loss of plants was the greatest – 11.7 thousand pieces/ha, when with a row spacing of 38 cm it was 10.6 thousand pieces/ha, and with a row spacing of 57 cm – 10.8 thousand. units/ha. At the same time, the level of competitive losses of plants also increased as the density of crops increased, at a density of 100,000 plants/ha they were 4.7 thousand plants/ha, at a density of 200,000 plants/ha – 10.7, and at a density of 300 thousand pieces/ha – 17.8 thousand pieces/ha.
It was established that 4.78 t/ha of dry matter was accumulated during the cultivation of the Dobrynya variety on the variant of the row width of 38 cm and the sowing rate of 300,000 plants/ha, and 4.83 t/ha when growing the Sonyachny variety with similar parameters.
The lowest level of weediness of safflower was determined for the cultivation of both studied varieties of safflower with a row spacing of 19 cm and a planting density of 300,000 pieces/ha. Accordingly, in general, according to the experiment, the lowest number of weeds in safflower crops was observed with a row width of 19 cm – 14.3 weeds/m2, while the growth of the row width to 38 cm increased by 4.6 weeds/m2, and 57 cm, the number increased by 11.7 pcs./m2 to the basic version of the experiment. As for the density of safflower crops, increasing the sowing rate, on the contrary, contributed to a lower level of crop weediness. Thus, at a density of 100,000 weeds/ha, there were 22.8 weeds/m2, at 200,000 weeds/ha – 19.5 weeds/m2, and at a density of 300,000 weeds/ha – 17.1 weeds/m2.
It was established that the area of the leaf surface of the dyeing safflower increased as the width of the rows and the rate of sowing increased, which emphasizes the importance of optimizing the location of plants in the field as a component of effective photosynthesis and subsequent crop formation. Thus, at the time of flowering in the Dobrynya variety, the leaf area was 32.7, and in the Sonyachny variety – 31.2 thousand m2/ha, the varieties differed in general by 1.5 thousand m2/ha, which exceeded the value of the smallest significant difference according to the experiment.
It was determined that during the period of budding of dye safflower plants in the Dobrynya variety, the best content of the amount of chlorophyll was on the options with a width of 38 cm between rows and a density of crops – 200 and 300 thousand pieces/ha – 5.21 and 5.24 mg/g of dry matter. Similarly, in the Sonyachny variety, the row width of 38 cm and the density of crops – 200 and 300 thousand units/ha contributed to the formation of the total chlorophyll content of 5.19 and 5.22 mg/g of dry matter.
It was also determined that, in general, over the years of research on the cultivation of the Dobrynya variety, the best indicators of seed mass per plant were obtained for the cultivation of plants with a row spacing of 19 cm and a seeding rate of 100,000 seeds/ha – 19.2 g/plant, while for the cultivation of the Sonyachny variety with a row width of 38 cm and a seeding rate of 100,000 pieces/ha, the best weight indicator according to the experiment was 19.5 g/plant.
