Kudrina V. Formation of sunflower productivity depending on the elements of growing technology in the conditions of the Southern Steppe of Ukraine

The dissertation work is devoted to the improvement of certain elements of sunflower growing technology in the conditions of the Southern Steppe of Ukraine using modern approaches to resource conservation, which contribute to the optimization of plant nutrition. Regularities of water consumption, growth and production processes of sunflower plants, formation of yield and quality of seeds by them during selection of biologics, their norms and term of use have been established. The positive effect of extracorporeal fertilization of sunflower plants in the main vegetation phases on the height of plants, their accumulation of above-ground biomass (raw and dry), the assimilation surface area is determined. It has been found that the treated plants keep the leaves green for a significantly longer period, they grow and accumulate biomass longer, and in general grain productivity in the end. When optimizing the nutrition of sunflower crops, on average 40% more lean moisture is used compared to the control - reserves of soil and sediment of the growing period. On average, over the years of research, the coefficient of water consumption, that is, the cost of water for the formation of a crop unit, decreases to 40-42%, and in dry years they use it even more efficiently. The grain yield when optimizing nutrition grew: for spraying sunflower crops in phase 3-4 pairs of leaves with various doses of the drug Fresh Energy, the yield changed from 3.3 tons/ha to 3.9 tons/ha, and in combination with Retardin to 4.2 tons/ha. When treating sunflower crops in the butonization phase, the yield increased from 3.3 tons/ha to 4.3 tons/ha. The effect of two feeding of sunflower crops in the 3-4 pairs of leaves and butonization phases was greatest, yields increased by 30.3% compared to the control. Close correlation relationships are defined between the level of sunflower yield and individual indicators of growth processes and crop structure. Studies have established the positive effect of biologics on the main indicators of seed quality. The mass of 1000 increases, the natural mass, the husk decreases and the fat content in the seeds and its conditional collection from a unit area increases significantly. The economic and energy efficiency of sunflower cultivation in the conditions of the Southern Steppe of Ukraine has been determined. Key words: sunflower, growth processes, photosynthetic activity, grain yield and quality, water consumption, economic and energy efficiency