Plant and Soil Science

The results of research on the effect of sowing and plant stand density of sunflower hybrids of different ripening periods on its yield in the Right-bank Steppe of Ukraine. Established that the limiting factor for growing sunflower in Ukraine steppe is soil moisture. On average, the most accessible moisture in the 0–10 cm layer of soil was when sown sunflower in the first term – when the soil is warmed at a depth of seed earnings of 5–6 0 C. By changing the timing of sowing and selecting the optimal plant density, we change the conditions for the growth and development of sunflower, bypassing the critical periods during the growth of cultivated plants. The duration of the interphase periods of the studied sunflower hybrids varied according to the timing of sowing, the biological peculiarities of the crop plants and the weather conditions. The optimal time of sowing of most sunflower hybrids in Right-bank steppe is warming the soil at a depth of earnings seeds to 7-8 0 C, the optimum density – 60 thousand pieces hectares. Under these conditions, the hybrid Forward had a yield of 3.07 t / ha, LG hybrid 56.32 – 3.55 t / ha, LG 55.82 – 3.68 t / ha, hybrid LG 54.85 – 3.66 t / ha.

sunflower, hybrids, sowing dates, density of plants standing, productive moisture, yield