Agrobiological and agrochemical aspects of increasing the yield of sunflower hybrids in the Saratov Trans-Volga region

  Abstract. The article provides an analysis of agrobiological (hybrids, seeding rate) and agrochemical (mineral fertilizers) aspects of increasing the yield and quality of sunflower in the Saratov Trans-Volga region. The results of three-year studies have established that the cultivation of the sunflower hybrid P64LE25 using Ammophos at a dose of 80 kg/ha before the main tillage and Sulfoammophos at a dose of 50 kg/ha when sown at a seeding rate of 60000 pcs. germinating seeds per 1 ha ensures the maximum yield of sunflower oilseeds - 2.02 t/ha. Increasing the seeding rate from 55 thousand to 65 thousand seeds/ha reduced the planting density and field germination by 3.2–3.4%. Mineral fertilization reduced field germination by 0.7–1.5%. The cultivation of the late-ripening hybrid P64LE25 increases the yield of oilseeds by 0.28 t/ha (by 18.8%), oil content by 2.5% compared to the mid-early hybrid P64F66. The seeding rate of 60000 pcs/ha increases the yield of the studied hybrids by 0.23 t/ha (by 15.4%). Mineral fertilization (N8P10S6) provides an increase in the yield of sunflower oil seeds - 0.24 t/ha (by 15.9%), and oil content by 0.4%.