YIELD OF SUNFLOWER SEEDS DEPENDING ON THE USE OFMINERAL FERTILIZERS AND BIOLOGICAL PRODUCTS

Abstract

The results of the influence of nitrogen-phosphorus fertilizers in combination with Vitavax 200 FF, Helafit Seeds and Helafit Combi on the yield of sunflower in the ForestSteppe of western Ukraine for 2018-2020 are presented. It was found that pre-sowing treatment of seeds with the chemical pesticide Vitavax 200 FF caused a decrease in plant density by 2.2 thousand/ha (4.1%), and the complex biological product Helafit Seeds, on the contrary, to some extent stimulated plant growth and development.
Sunflower plants formed a powerful leaf surface, which reached its maximum value in the flowering phase. This indicator gradually increased from 30.9 thousand m2/ha on the control without fertilizers to 40.0 thousand m2/ha on the background of N30P45 + Helafit Combi and to 44.2 thousand m2/ha on the background of N60P90 + Helafit Combi.
The combined use of nitrogen-phosphorus fertilizers and the drug Helafit Combi caused a prolongation of the photosynthetic activity of the leaves for 6-8 days and provided an increase in the photosynthetic potential of sunflower plants by 64.7-95.8%. Under these conditions, the highest yield of dry biomass was achieved – 8.2-8.8 t/ha and the highest seed yield – 3.03-3.11 t/ha. Analysis of crop structure elements showed that the increase in seed productivity was due to an increase in the number of seeds in the flower head (34.1%) and the weight of seeds from one flower head (41.3%). The best economic indicators were provided by the joint use of N30P45 and the drug Helafit Combi: the profit was UAH 19,120 / ha, the cost of 1 ton of seeds – UAH 4,690, the level of profitability – 134%. Increasing the rate of fertilizer to N60P90 negatively affected the economy of sunflower cultivation.